JPH09171952A - Formation of resist pattern and production of semiconductor device employing it - Google Patents

Formation of resist pattern and production of semiconductor device employing it

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Publication number
JPH09171952A
JPH09171952A JP33332495A JP33332495A JPH09171952A JP H09171952 A JPH09171952 A JP H09171952A JP 33332495 A JP33332495 A JP 33332495A JP 33332495 A JP33332495 A JP 33332495A JP H09171952 A JPH09171952 A JP H09171952A
Authority
JP
Japan
Prior art keywords
film
resist
antireflection film
resist pattern
antireflection
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
JP33332495A
Other languages
Japanese (ja)
Inventor
Yasuhiko Sato
康彦 佐藤
Masashi Asano
昌史 浅野
Shinichi Ito
信一 伊藤
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Toshiba Corp
Original Assignee
Toshiba Corp
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Toshiba Corp filed Critical Toshiba Corp
Priority to JP33332495A priority Critical patent/JPH09171952A/en
Publication of JPH09171952A publication Critical patent/JPH09171952A/en
Pending legal-status Critical Current

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Abstract

PROBLEM TO BE SOLVED: To enhance the machining accuracy of a work by suppressing the reflection of exposing light from the work side to the resist side as much as possible and increasing the total exposing light absorption efficiency of anti- reflection film thereby making thin the anti-reflection film sufficiently. SOLUTION: An anti-reflection film 5 and a resist 1 are formed sequentially on a work and then the resist 1 is subjected to selective exposure and development thus forming a resist pattern. Extinction coefficient of the anti-reflection film 5 at the wavelength of exposing light is set to prevent reflection of exposing light on the interface between the resist 1 and anti-reflection film 5 and to increase from the interface to resist toward the interface to work.

Description

【発明の詳細な説明】Detailed Description of the Invention

【０００１】[0001]

【発明の属する技術分野】本発明はレジストパターン形
成方法及びそのレジストパターン形成方法を用いた半導
体装置の製造方法に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resist pattern forming method and a semiconductor device manufacturing method using the resist pattern forming method.

【０００２】[0002]

【従来の技術】半導体素子の製造方法においては、シリ
コンウェハー上に複数の物質を堆積し、所望のパターン
にパターニングする工程を多く含んでいる。このパター
ニング工程は、まず、シリコンウェハー上に形成された
絶縁体、導体、半導体薄膜上にフォトレジスト膜をスピ
ンコーテング法等により形成し、選択的にフォトレジス
トを露光した後、現像工程を経てレジストパターンを形
成する。さらにこのレジストパターンをエッチングマス
クとして基板上に形成された被加工物である絶縁体、導
体、半導体薄膜をエッチングすることにより、微細な配
線や開孔等を所望のパターンに加工することによってな
される。2. Description of the Related Art A method of manufacturing a semiconductor device includes many steps of depositing a plurality of substances on a silicon wafer and patterning them into a desired pattern. In this patterning process, first, a photoresist film is formed on the insulator, conductor, or semiconductor thin film formed on a silicon wafer by spin coating, etc., the photoresist is selectively exposed, and then a developing process is performed to form the resist. Form a pattern. Further, the resist pattern is used as an etching mask to etch the insulators, conductors, and semiconductor thin films that are workpieces formed on the substrate to process fine wiring, openings, etc. into a desired pattern. .

【０００３】この工程においては、レジストパターンの
寸法を高精度で制御することが重要である。しかし、実
際には、露光光に対して高い反射率を有する基板上のパ
ターン形成工程において、レジストパターンの側壁がレ
ジスト膜中で発生した定在波のために波打ち形状となっ
たり、基板段差部からの反射光の作用によって局所的な
レジスト寸法の変動やプロファイルの劣化が生じる場合
がある。In this process, it is important to control the dimensions of the resist pattern with high accuracy. However, actually, in the pattern forming process on the substrate having a high reflectance for the exposure light, the side wall of the resist pattern becomes wavy due to the standing wave generated in the resist film, or the substrate step portion is formed. There is a case where a resist dimension locally varies or a profile is deteriorated due to the action of reflected light from.

【０００４】また、レジスト直下に露光光に対して比較
的透明な珪素酸化物や珪素窒化物が存在する場合には、
露光光はこれらの膜中で多重反射する。それゆえ、これ
らの膜厚が変動すると上記多重反射の振る舞いがその影
響を受ける。その結果、実質的にレジスト層に与えられ
る光エネルギーの量が変動し、レジスト寸法の制御性に
重大な影響を及ぼす。When silicon oxide or silicon nitride, which is relatively transparent to exposure light, is present immediately below the resist,
Exposure light is multiply reflected in these films. Therefore, if these film thicknesses change, the behavior of the multiple reflection is affected. As a result, the amount of light energy provided to the resist layer varies substantially, which has a significant effect on the controllability of the resist size.

【０００５】さらには、レジスト膜中でも多重反射がお
こるためレジスト膜厚の変動がある場合にはやはり寸法
変動に大きな影響を及ぼす。上記の問題を解決するため
に、レジストと基板との間に反射防止膜を形成する方法
が採られている。この方法では、基板と反射防止膜との
界面で反射した光とレジストと反射防止膜との界面で反
射した光を反射防止膜による露光光の吸収と位相の反転
により打ち消すことで、再度レジスト層に反射する光の
強度を著しく弱めることができ、基板段差からの露光光
の反射やレジスト膜厚の変動に伴うレジストの寸法変動
やプロファイルの劣化を低減することができる。Further, since multiple reflection occurs even in the resist film, when the resist film thickness fluctuates, the dimensional fluctuation is also greatly affected. In order to solve the above problems, a method of forming an antireflection film between a resist and a substrate is adopted. In this method, the light reflected at the interface between the substrate and the antireflection film and the light reflected at the interface between the resist and the antireflection film are canceled by absorption of the exposure light by the antireflection film and phase inversion, whereby the resist layer It is possible to significantly weaken the intensity of the light reflected on the substrate, and it is possible to reduce the dimensional variation of the resist and the deterioration of the profile due to the reflection of the exposure light from the substrate step and the variation of the resist film thickness.

【０００６】一方、下地が透明膜の場合、透明膜の膜厚
変動に対するレジストパターンの寸法変動を防ぐために
は、反射防止膜中で露光光を吸収し透明膜に入射する露
光光の強度を可能な限り減じる必要がある。露光波長に
対する消衰係数がｋの膜中を強度Ｉの光がｘだけ進んだ
時、強度はＩｅｘｐ（−４πｋｘ／λ）に減じられる。
従って、露光光に対する消衰係数ｋと反射防止膜の膜厚
ｄのいずれかの変数を大きくすることで、反射防止膜中
で吸収される光強度は増大し、透明膜まで到達できる光
を減じせしめることができる。On the other hand, when the underlayer is a transparent film, in order to prevent the dimensional variation of the resist pattern due to the variation of the film thickness of the transparent film, the intensity of the exposure light which is absorbed in the antireflection film and is incident on the transparent film is possible. It is necessary to reduce it as much as possible. When the light having the intensity I advances by x in the film having the extinction coefficient k with respect to the exposure wavelength, the intensity is reduced to Iexp (-4πkx / λ).
Therefore, by increasing either the extinction coefficient k for the exposure light or the film thickness d of the antireflection film, the light intensity absorbed in the antireflection film is increased and the light that can reach the transparent film is reduced. It can be done.

【０００７】ところで、反射防止膜の膜厚は薄い方が反
射防止膜のエッチング時に生じる寸法変換差及びレジス
ト削れが小さく所望の寸法に加工すべき被加工物の寸法
精度を向上させることができるため、反射防止膜の膜厚
を厚くすることは好ましくない。従って、このような場
合には透明膜に到達する光強度を可能な限り抑え、かつ
反射防止膜を薄膜化するには、消衰係数ｋを大きくする
方が好ましい。By the way, the smaller the thickness of the antireflection film is, the smaller the dimensional conversion difference and the resist scraping that occur during etching of the antireflection film are, and the dimensional accuracy of the workpiece to be processed into a desired dimension can be improved. However, it is not preferable to increase the thickness of the antireflection film. Therefore, in such a case, it is preferable to increase the extinction coefficient k in order to suppress the light intensity reaching the transparent film as much as possible and reduce the thickness of the antireflection film.

【０００８】しかしながら、レジスト反射防止膜界面で
の光反射率Ｒは、反射防止膜内で光が吸収され下地基板
に光が到達しない時、レジストと反射防止膜の露光波長
での複素屈折率をそれぞれｎ＋ｉｋ、ｎ1 ＋ｉｋ1 とす
ると、（１）式のように表すことができ、 Ｒ＝（（ｎ−ｎ1 ）2 ＋（ｋ−ｋ1 ）2 ） ／（（ｎ＋ｎ1 ）2 ＋（ｋ＋ｋ1 ）2 ） …（１） 反射防止膜の消衰係数ｋを大きくしすぎると、結果的に
光反射率Ｒが大きくなり、レジストの膜厚変動に対して
レジストパターンの寸法変動が顕著になるという問題が
生じる。However, the light reflectance R at the resist antireflection film interface is the complex refractive index at the exposure wavelength of the resist and antireflection film when the light is absorbed in the antireflection film and does not reach the underlying substrate. each n + ik, When n 1 + ik 1, (1 ) can be represented as equation, R = ((n-n 1) 2 + (k-k 1) 2) / ((n + n 1) 2 + ( k + k 1 ) 2 ) (1) If the extinction coefficient k of the antireflection film is made too large, the light reflectance R becomes large as a result, and the dimensional fluctuation of the resist pattern becomes remarkable with respect to the fluctuation of the resist film thickness. The problem arises.

【０００９】つまり、これは反射防止膜を用いないとき
に被加工物の光反射率が高いとレジストパターン寸法の
変動量が大きくなるという問題に帰結し、当該問題には
いくつかの報告（例えばT.A.Brunner,SPIE,Vol、1466,p
p.297-308）があるのでここでは細述しないが、これは
レジスト膜内での定在波発生によって、レジスト膜厚の
変化に対する露光光の吸収分率が波打ち状に変化するこ
とによるものである。That is, this results in the problem that the variation of the resist pattern size becomes large when the light reflectance of the workpiece is high when the antireflection film is not used. TABrunner, SPIE, Vol, 1466, p
I will not go into detail here because of the presence of standing waves in the resist film, but this is because the absorption fraction of the exposure light changes in a wavy shape with respect to changes in the resist film thickness. Is.

【００１０】以上のことから、レジスト及び被加工物内
に発生する定在波の抑制と反射防止膜の薄膜化の要請を
同時に満たす材料を選定するのは困難である。また、反
射防止膜の材料としては、プラズマ分解型のポリサルフ
ォン等の樹脂に露光波長を吸収するクマリン、クルクミ
ン等の染料を加えたスピンコーテング法により成膜が可
能な反射防止膜が特開昭５９−９３４４８等に開示され
ている。これら有機化合物からなる反射防止膜では、露
光波長に対する複素屈折率の値が、例えばエキシマレー
ザー光の波長（λ＝２４８ｎｍ）では屈折率が１．５か
ら１．９、消衰係数が０から０．４程度と狭い範囲に限
られており、被加工物内での多重反射を抑えるために反
射防止膜の膜厚が厚くなるという問題が生じる。From the above, it is difficult to select a material that simultaneously satisfies the requirements of suppressing standing waves generated in the resist and the workpiece and reducing the thickness of the antireflection film. Further, as a material of the antireflection film, an antireflection film which can be formed by a spin coating method in which a dye such as coumarin or curcumin that absorbs an exposure wavelength is added to a resin such as plasma decomposition type polysulfone is disclosed. -93448 and the like. In the antireflection film made of these organic compounds, the value of the complex refractive index with respect to the exposure wavelength is, for example, at the wavelength of the excimer laser light (λ = 248 nm), the refractive index is 1.5 to 1.9, and the extinction coefficient is 0 to 0. It is limited to a narrow range of about 0.4, and there arises a problem that the film thickness of the antireflection film becomes large in order to suppress multiple reflection in the workpiece.

【００１１】また、反射防止膜を構成する有機化合物の
種類によってレジストパターンの反射防止膜の界面付近
の形状が顕著に変化するため、良好なレジストプロファ
イルと反射防止効果の高い複素屈折率の相方を満たす材
料を見い出すことが難しかった。Further, since the shape of the resist pattern near the interface of the antireflection film remarkably changes depending on the type of the organic compound constituting the antireflection film, a good resist profile and a complex refractive index having a high antireflection effect are used. It was difficult to find the material to fill.

【００１２】一方、特開平４−２３４１０９では、反射
防止膜が少なくとも被加工物上に接して露光光を吸収す
る層と、レジストの直下に接して反射光の定在波を生じ
させる緩衝層とからなることを特徴とする反射防止方法
が開示されている。しかしながら、本方法では緩衝層の
露光波長に対する消衰係数が０．００５程度の透明膜で
あるため、露光光に対する吸収を十分に確保するために
は、緩衝層を有する分だけ反射防止膜全体として厚くな
らざるを得ない。On the other hand, in Japanese Unexamined Patent Publication No. 4-234109, an antireflection film is at least in contact with the work piece to absorb the exposure light, and a layer directly below the resist to generate a standing wave of the reflected light. An antireflection method comprising the following is disclosed. However, in this method, since the extinction coefficient of the buffer layer with respect to the exposure wavelength is about 0.005, in order to sufficiently secure the absorption of the exposure light, the antireflection film as a whole has only the buffer layer in order to ensure sufficient absorption. There is no choice but to thicken it.

【００１３】また、消衰係数が極端に小さい透明膜を用
いる関係上、当該透明膜（緩衝膜）と吸収層との間で、
露光光が反射し、その反射光はレジスト内に戻ることと
なる。Since a transparent film having an extremely small extinction coefficient is used, between the transparent film (buffer film) and the absorption layer,
The exposure light is reflected, and the reflected light returns to the inside of the resist.

【００１４】したがって、特開平４−２３４１０９の場
合であっても、状況に対応して十分薄い反射防止膜を実
現し、かつ、レジストに戻る光反射を充分に抑えること
ができないものと考えられる。Therefore, even in the case of Japanese Unexamined Patent Publication (Kokai) No. 4-234109, it is considered that it is impossible to realize a sufficiently thin antireflection film depending on the situation and sufficiently suppress the light reflection returning to the resist.

【００１５】[0015]

【発明が解決しようとする課題】以上のことから、従来
の反射防止膜の問題点をまとめると次の通りである。反
射防止膜が単層である場合、レジストに対する被加工物
からの光の戻りを十分に押さえるためには、反射防止膜
を厚くする必要があり、これでは、細微な加工を行うに
当たって十分な加工精度を得られない。一方、反射防止
膜を薄くすると、上記被加工物からの光の戻りが大きく
なり、レジスト膜のパターン寸法の変動量が大きくな
る。From the above, the problems of the conventional antireflection film are summarized as follows. When the antireflection film is a single layer, it is necessary to thicken the antireflection film in order to sufficiently suppress the return of light from the work piece to the resist, which is sufficient for fine processing. I can't get the accuracy. On the other hand, if the antireflection film is made thin, the return of light from the workpiece increases, and the amount of variation in the pattern dimension of the resist film increases.

【００１６】また、薄い反射防止膜により被加工物から
の光の戻りを押さえるために、単に消衰係数ｋを大きく
して反射防止膜内での吸収を大きくしようとすると、
（１）式より今度はレジスト・反射防止膜界面での光反
射が大きくなり、やはりレジスト膜のパターン寸法の変
動量が大きくなる。Further, in order to suppress the return of light from the workpiece by the thin antireflection film, if the extinction coefficient k is simply increased to increase the absorption in the antireflection film,
According to the equation (1), the light reflection at the interface between the resist and the antireflection film becomes large, and the variation of the pattern dimension of the resist film becomes large.

【００１７】さらに、反射防止膜を多層にした場合、反
射防止膜全体として厚いものとなる。また、反射防止膜
内の各層間での反射により、レジスト側に反射光が戻る
こととなる。Further, when the antireflection film has a multi-layer structure, the total thickness of the antireflection film is large. Further, the reflected light returns to the resist side due to the reflection between the respective layers in the antireflection film.

【００１８】本発明は、このような実情を考慮してなさ
れたもので、被加工物側からレジスト側への露光光の反
射を極力押さえ、かつ、反射防止膜全体での露光光吸収
効率を高くして反射防止膜を十分に薄くすることを可能
とし、これらにより被加工物の加工精度の高いレジスト
パターン形成方法及びそのレジストパターン形成方法を
用いた半導体装置の製造方法を提供することを目的とす
る。The present invention has been made in consideration of such a situation, and suppresses the reflection of exposure light from the workpiece side to the resist side as much as possible, and the exposure light absorption efficiency of the entire antireflection film. An object of the present invention is to provide a resist pattern forming method with high processing accuracy of a workpiece and a method of manufacturing a semiconductor device using the resist pattern forming method, by making it possible to make the antireflection film sufficiently thin by making it high. And

【００１９】[0019]

【課題を解決するための手段】上記課題を解決するため
に、請求項１に対応する発明は、被加工物上に反射防止
膜、レジストを順次形成し、レジストを選択的に露光、
現像を行いレジストパターンを形成するレジストパター
ン形成方法において、レジストと反射防止膜との界面に
おける当該反射防止膜の露光波長に対する消衰係数を界
面での露光光反射を防止する大きさとし、かつ、当該反
射防止膜の消衰係数をレジストとの界面側から被加工物
との界面側に向って増大するように設定するレジストパ
ターン形成方法である。In order to solve the above-mentioned problems, the invention corresponding to claim 1 is that an antireflection film and a resist are sequentially formed on a workpiece, and the resist is selectively exposed,
In a resist pattern forming method for forming a resist pattern by developing, an extinction coefficient for the exposure wavelength of the antireflection film at the interface between the resist and the antireflection film is set to a size that prevents exposure light reflection at the interface, and This is a resist pattern forming method in which the extinction coefficient of the antireflection film is set so as to increase from the interface side with the resist toward the interface side with the workpiece.

【００２０】また、請求項２に対応する発明は、請求項
１に対応する発明において、反射防止膜の消衰係数をレ
ジストとの界面側から被加工物との界面側に向って連続
的に増大するような部分を少なくとも設けるレジストパ
ターン形成方法である。The invention according to claim 2 is the invention according to claim 1, wherein the extinction coefficient of the antireflection film is continuously changed from the interface side with the resist toward the interface side with the workpiece. This is a method of forming a resist pattern in which at least an increasing portion is provided.

【００２１】さらに、請求項３に対応する発明は、被加
工物上に反射防止膜、レジストを順次形成し、レジスト
を選択的に露光、現像を行いレジストパターンを形成す
るレジストパターン形成方法において、反射防止膜は、
レジストと接する第１の膜と、被加工物と接する第２の
膜との少なくとも２層からなり、第１の膜は、レジスト
と反射防止膜との界面における当該反射防止膜の露光波
長に対する消衰係数を、露光波長に対して吸収性を有
し、かつ界面での露光光反射を防止する大きさとし、第
２の膜は、第１の膜よりも露光波長に対する吸収性が高
い膜とするレジストパターン形成方法である。Further, the invention according to claim 3 is a method for forming a resist pattern, wherein an antireflection film and a resist are sequentially formed on a workpiece, and the resist is selectively exposed and developed to form a resist pattern. The antireflection film is
It is composed of at least two layers of a first film in contact with the resist and a second film in contact with the workpiece, and the first film has a function of eliminating the exposure wavelength of the antireflection film at the interface between the resist and the antireflection film. The extinction coefficient is set to a size that has an absorptivity to the exposure wavelength and prevents exposure light reflection at the interface, and the second film is a film having a higher absorptivity to the exposure wavelength than the first film. It is a method of forming a resist pattern.

【００２２】次に、請求項４に対応する発明は、請求項
３に対応する発明において、第１の膜の厚さと第２の膜
の厚さの組み合わせの中で、露光光のレジスト側への戻
りが極小となり、かつ、反射防止膜全体の厚さを最も薄
くする組み合わせを選択するレジストパターン形成方法
である。Next, the invention according to claim 4 is, in the invention according to claim 3, in the combination of the thickness of the first film and the thickness of the second film, to the resist side of the exposure light. Is a resist pattern forming method in which the return is minimized and the combination that minimizes the total thickness of the antireflection film is selected.

【００２３】また、請求項５に対応する発明は、請求項
１〜４のうち、何れか一項記載のレジストパターン形成
方法を用いた半導体装置の製造方法である。したがっ
て、まず、請求項１に対応する発明のレジストパターン
形成方法においては、被加工物上に反射防止膜を用いる
形式のレジストパターン形成方法を取り扱っている。An invention corresponding to claim 5 is a method of manufacturing a semiconductor device using the resist pattern forming method according to any one of claims 1 to 4. Therefore, first, in the resist pattern forming method of the invention corresponding to claim 1, a resist pattern forming method of a type using an antireflection film on a workpiece is dealt with.

【００２４】ここで、レジストと反射防止膜との界面に
おける当該反射防止膜の露光波長に対する消衰係数を界
面での露光光反射を防止できる大きさとし、この段階で
のレジストへの露光光の戻りを確実に防止している。Here, the extinction coefficient of the antireflection film with respect to the exposure wavelength at the interface between the resist and the antireflection film is set to a size that can prevent exposure light reflection at the interface, and the exposure light returns to the resist at this stage. Is surely prevented.

【００２５】さらに、当該反射防止膜の消衰係数をレジ
ストとの界面側から被加工物との界面側に向って増大す
るように設定し、反射防止膜内での露光光の吸収を十分
に行って、被加工物の影響によりレジスト側に露光光の
戻る状況があっても、反射防止膜内での吸収で、レジス
ト側への戻りを極力少なくしている。Further, the extinction coefficient of the antireflection film is set so as to increase from the interface side with the resist toward the interface side with the workpiece, and the absorption of the exposure light in the antireflection film is sufficiently performed. Even if there is a situation where the exposure light returns to the resist side due to the influence of the processed object, the return to the resist side is minimized by the absorption in the antireflection film.

【００２６】また、消衰係数が被加工物側に向って増大
することから、反射防止膜全体での露光光吸収効率が高
く、反射防止膜を十分に薄くことができる。したがっ
て、上記両者の効果により被加工物の加工精度を高く
し、被加工物の種類や各種膜厚変動にかかわらず、レジ
ストパターンの寸法変動を抑えることが可能となる。Further, since the extinction coefficient increases toward the workpiece, the exposure light absorption efficiency of the entire antireflection film is high and the antireflection film can be made sufficiently thin. Therefore, it is possible to improve the processing accuracy of the workpiece by the effects of both of the above, and suppress the dimensional variation of the resist pattern regardless of the type of the workpiece and various film thickness variations.

【００２７】なお消衰係数を変化させる方法の例として
は、反射防止膜を消衰係数の異なる複数層の膜をスピン
コーテング法、蒸着法、スパッター法、ＣＶＤ法等の物
理的成膜方法で被加工物上に順次形成していく方法、物
理的成膜方法で成膜を行う際に基板温度、ガスの流量等
の成膜条件を時間と共に変化させる方法、或は反射防止
膜の成膜後、光照射、プラズマ照射、熱の照射、化学処
理等を行い膜厚方向に物性の変化を持たせる方法、反射
防止膜の成膜時に露光波長を吸収する染料等に膜厚方向
で分布をもたせる方法等があるが特に限定させることは
ない。As an example of the method of changing the extinction coefficient, a physical film forming method such as a spin coating method, a vapor deposition method, a sputtering method, a CVD method or the like is used as the antireflection film to form a plurality of layers having different extinction coefficients. Method of sequentially forming on work piece, method of changing film forming conditions such as substrate temperature and gas flow rate with time when forming by physical film forming method, or film formation of antireflection film After that, light irradiation, plasma irradiation, heat irradiation, chemical treatment, etc. are performed to change the physical properties in the film thickness direction, and the dye etc. that absorbs the exposure wavelength during the formation of the antireflection film is distributed in the film thickness direction. There is a method of giving it, but the method is not particularly limited.

【００２８】また、レジストとの界面側での反射防止膜
の消衰係数は、被加工物側の消衰係数と比べて、複素屈
折率の膜厚方向での分布を調節することで、被加工物の
表面からレジストへ反射する光強度を減衰させることが
可能である。The extinction coefficient of the antireflection film on the interface side with the resist is adjusted by adjusting the distribution of the complex refractive index in the film thickness direction as compared with the extinction coefficient on the side of the workpiece. It is possible to attenuate the light intensity reflected from the surface of the work piece to the resist.

【００２９】つまり、反射防止膜の膜厚方向での複素屈
折率の分布は、例えば多層膜中の多重反射をも考慮した
計算によりレジストと反射防止膜界面での光反射率や透
過率の計算を行い決定すればよい。That is, the distribution of the complex refractive index in the film thickness direction of the antireflection film is calculated, for example, by considering the multiple reflection in the multilayer film, and the calculation of the light reflectance and the transmittance at the interface between the resist and the antireflection film. And decide.

【００３０】このようにすれば、単純に消衰係数の増大
による露光光吸収効果以上の反射防止効果を期待でき
る。なお、かかる計算の方法は、Ｐ．Ｈ．Ｂｅｒｎｉｎ
ｇ：Ｐｈｙｓｉｃｓ ｏｆＴｈｉｎ Ｆｉｌｍ．Ｖｏ
ｌ．１，ｐｐ６９−１２１（１９６３），Ａ．Ｅ．Ｂｒ
ｌｌ＆Ｆ．Ｗ．Ｓｐｏｎｇ：ＩＥＥＥ Ｊｏｕｒｎａｌ
ｏｆ Ｑｕａｎｔｕｍ Ｅｌｅｃｔｒｏｎｉｃｓ，Ｖ
ｉｌ．ＱＥ−１４，ｐｐ４８７−９５（１９７８），
Ｋ．Ｏｈｔａ＆Ｈ．Ｉｓｉｄａ：Ａｐｐｌｉｅｄ Ｏｐ
ｔｉｃｓ，Ｖｏｌ．２９，ｐｐ１９５２−１９５８（１
９９０）などに詳述されている方法で行うことができ
る。By doing so, it is possible to expect an antireflection effect that is greater than the exposure light absorption effect by simply increasing the extinction coefficient. The calculation method is described in P. H. Bernin
g: Physics of Thin Film. Vo
l. 1, pp69-121 (1963), A.I. E. FIG. Br
ll & F. W. Spong: IEEE Journal
of Quantum Electronics, V
il. QE-14, pp487-95 (1978),
K. Ohta & H.A. Isida: Applied Op
tics, Vol. 29, pp1952-1959 (1
990) and the like.

【００３１】また、請求項２に対応する発明のレジスト
パターン形成方法においては、請求項１に対応する発明
と同様に作用する他、反射防止膜の消衰係数がレジスト
との界面側から被加工物との界面側に向って連続的に増
大するような部分を少なくとも設けている。Further, in the resist pattern forming method of the invention according to claim 2, the same action as in the invention according to claim 1 is achieved, and the extinction coefficient of the antireflection film is processed from the interface side with the resist. At least a portion that continuously increases toward the interface with the object is provided.

【００３２】このように反射防止膜を多層構造にせず、
消衰係数を連続的に変化させることにより、反射防止膜
内の反射を確実に防止することができる。つまり、なん
らかの目的のために、反射防止膜を多層構造にした場
合、従来技術でも説明した通り、その層間での反射によ
り露光光がレジストに戻るという現象を生じる。これに
よりパターン寸法の変動量が大きくなる。この変動量の
増加は、寸法精度が高くない場合にはあまり問題がない
が、超細微な加工を行う場合には、このようなわずかな
パターン寸法の変動も問題となり、上記層間での反射を
も防止することが望ましい。As described above, the antireflection film does not have a multi-layer structure,
By continuously changing the extinction coefficient, it is possible to reliably prevent reflection in the antireflection film. That is, when the antireflection film has a multi-layer structure for some purpose, as described in the prior art, the phenomenon that the exposure light returns to the resist due to the reflection between the layers occurs. As a result, the variation amount of the pattern size becomes large. This increase in the amount of variation does not cause much problem if the dimensional accuracy is not high, but when performing ultra-fine processing, such a slight variation in the pattern dimension also poses a problem, causing reflection between the layers. It is desirable to prevent

【００３３】本請求項に対応する発明によれば、この反
射防止膜内に層を設けないで消衰係数を変化させるの
で、層間での反射が起こることもなく、その目的をより
確実に達成することが可能である。According to the invention corresponding to the present claim, since the extinction coefficient is changed without providing a layer in the antireflection film, reflection between layers does not occur and the object can be achieved more reliably. It is possible to

【００３４】さらにまた、請求項３に対応する発明のレ
ジストパターン形成方法においては、、被加工物上に反
射防止膜を用いる形式のレジストパターン形成方法を取
り扱っている。Furthermore, in the resist pattern forming method of the invention according to claim 3, a resist pattern forming method of using an antireflection film on a workpiece is dealt with.

【００３５】この、反射防止膜は、レジストと接する第
１の膜と、被加工物と接する第２の膜との少なくとも２
層からなっている。ここで、第１の膜は、レジストと反
射防止膜との界面における当該反射防止膜の露光波長に
対する消衰係数を界面での露光光反射を防止できる大き
さとし、この段階でのレジストへの露光光の戻りを確実
に防止するとともに、屈折率と消衰係数とからなる複素
屈折率の値を調整することで、上記反射防止要件を満た
しつつ、その消衰係数を露光波長に対して吸収性を有す
る大きさとしている。The antireflection film has at least two layers, a first film that contacts the resist and a second film that contacts the workpiece.
It consists of layers. Here, the first film has an extinction coefficient with respect to the exposure wavelength of the antireflection film at the interface between the resist and the antireflection film of a size that can prevent exposure light reflection at the interface, and the exposure of the resist at this stage is performed. By reliably preventing the return of light and adjusting the value of the complex index of refraction consisting of the index of refraction and the extinction coefficient, the extinction coefficient can be absorbed by the exposure wavelength while satisfying the above antireflection requirements. Has a size.

【００３６】一方、第２の膜は、第１の膜よりも露光波
長に対する吸収性が高い膜とし、第１、第２の膜の相乗
効果により、反射防止膜内での露光光の吸収を十分に行
って、被加工物の影響によりレジスト側に露光光の戻る
状況があっても、反射防止膜内での吸収で、レジスト側
への戻りを極力少なくしている。On the other hand, the second film is a film having a higher absorptivity to the exposure wavelength than the first film, and the synergistic effect of the first and second films causes the absorption of the exposure light in the antireflection film. Even if there is a situation in which the exposure light returns to the resist side due to the effect of the workpiece, the return to the resist side is minimized by the absorption in the antireflection film.

【００３７】また、このように反射防止膜全体での露光
光吸収効率が高いことから、反射防止膜を十分に薄くこ
とができる。また、仮に第１の膜、第２の膜界面等の反
射防止膜内の層間での反射があった場合でも、第１の膜
が露光光の吸収性を有するため、露光光のレジストへの
戻りを十分に抑制することができる。Further, since the exposure light absorption efficiency of the entire antireflection film is high as described above, the antireflection film can be made sufficiently thin. Even if there is reflection between the layers in the antireflection film such as the interface between the first film and the second film, the first film has a property of absorbing the exposure light, so that the resist does not absorb the exposure light. The return can be suppressed sufficiently.

【００３８】したがって、上記各効果により被加工物の
加工精度を高くし、被加工物の種類や各種膜厚変動にか
かわらず、レジストパターンの寸法変動を抑えることが
可能となる。Therefore, it is possible to improve the processing accuracy of the work piece by the above respective effects and suppress the dimensional change of the resist pattern regardless of the kind of the work piece and various film thickness changes.

【００３９】なお、第１，第２の膜として使用する材料
の例としては、高温で熱酸化された酸化ノボラック膜、
ポリサルフォン、ポリアミド、ポリイミド等の官能基が
露光波長を吸収するもの、或はこれらの樹脂やポリメチ
ルメタクレラート、ポリイソブチルケトン等のプラズマ
に分解しやすい樹脂に露光波長を吸収するクマリン、ク
ルクミン等の染料を加えたもの、ＳｉＣ、ＳｉＮ、Ｓｉ
Ｏ、ＭｏＳｉ、ＴｉＮ、カーボン膜、露光波長を吸収す
る染料を加えたＳＯＧ等が挙げられるが特に限定はされ
ない。As an example of the material used as the first and second films, an oxide novolac film thermally oxidized at a high temperature,
Functional groups such as polysulfone, polyamide, and polyimide that absorb the exposure wavelength, or coumarin, curcumin, etc. that absorb the exposure wavelength in these resins and resins that easily decompose into plasma such as polymethylmethacrylate and polyisobutylketone. With added dye, SiC, SiN, Si
Examples thereof include O, MoSi, TiN, a carbon film, and SOG to which a dye that absorbs the exposure wavelength is added, but are not particularly limited.

【００４０】また、この本発明のように反射防止膜が複
数層からなる場合、それらの膜が同一エッチング条件で
一度にエッチング除去できる材料で構成される方が望ま
しい。 また、本請求項に対応する発明では、レジスト
の直下に形成された膜の消衰係数は、被加工物の直上に
形成された膜の消衰係数より低く設定されているためレ
ジストの直下に形成された膜の膜厚を調節することで、
レジストの直下に形成された膜の表面と裏面での光の位
相の相殺効果と吸収でレジスト膜中に被加工物から反射
する光を減衰させることができる。When the antireflection film is composed of a plurality of layers as in the present invention, it is preferable that the films are made of a material that can be removed by etching at the same time under the same etching conditions. Further, in the invention corresponding to this claim, the extinction coefficient of the film formed immediately below the resist is set lower than the extinction coefficient of the film formed immediately above the workpiece, so that the extinction coefficient immediately below the resist is set. By adjusting the film thickness of the formed film,
The light reflected from the workpiece in the resist film can be attenuated by the effect of offsetting and absorbing the phase of the light on the front surface and the back surface of the film formed immediately below the resist.

【００４１】つまり、反射防止膜を構成する薄膜の膜厚
は、多層膜中の多重反射を考慮した計算によりレジスト
と反射防止膜界面での光反射率や透過率を求め決定すれ
ば、より効果的に露光光の反射を防止し、その効果が高
い値の中から反射防止膜が薄くなるような膜厚の組み合
わせを選択することができる。That is, the film thickness of the thin film forming the antireflection film is more effective if the light reflectance and the transmittance at the interface between the resist and the antireflection film are determined by calculation by taking into consideration the multiple reflection in the multilayer film. It is possible to select a combination of film thicknesses that can prevent the reflection of the exposure light and reduce the thickness of the antireflection film from among the values having a high effect.

【００４２】つまり、請求項４に対応する発明のレジス
トパターン形成方法においては、請求項３に対応する発
明と同様に作用する他、上記組み合わせの中で反射防止
効果の高いものの中から反射防止膜全体の厚さが最も薄
くなる組み合わせを選択している。That is, in the resist pattern forming method of the invention according to claim 4, the same action as that of the invention according to claim 3 is achieved, and the antireflection film is selected from the combinations having a high antireflection effect. The combination that gives the smallest overall thickness is selected.

【００４３】具体的には、第１の膜の厚さと第２の膜の
厚さの組み合わせの中で、露光光のレジスト側への戻り
が極小となるものを選択している。なお、いうまでもな
いが、ここで極小というのは、極小値となる点そのもの
指すのではなく、極小値付近における反射防止効果の高
い領域を指している。Specifically, the combination of the thickness of the first film and the thickness of the second film that minimizes the return of the exposure light to the resist side is selected. Needless to say, the local minimum here does not refer to the point where the local minimum value is obtained, but to a region having a high antireflection effect near the local minimum value.

【００４４】また、請求項５に対応する発明に対応する
半導体装置の製造方法においては、請求項１〜４の何れ
かに対応するレジストパターン形成方法を用いているの
で、被加工物の加工精度のすぐれた半導体装置の製造方
法を提供できる。Further, in the method of manufacturing a semiconductor device corresponding to the invention according to claim 5, since the resist pattern forming method according to any one of claims 1 to 4 is used, the processing accuracy of the work piece is improved. An excellent semiconductor device manufacturing method can be provided.

【００４５】[0045]

【発明の実施の形態】以下、本発明の実施の形態につい
て説明する。 （発明の第１の実施の形態）図１は本発明の第１の実施
の形態に係るレジストパターン形成方法を適用したレジ
ストパターンの一例を示す構成図である。BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below. (First Embodiment of the Invention) FIG. 1 is a structural view showing an example of a resist pattern to which a resist pattern forming method according to a first embodiment of the present invention is applied.

【００４６】同図に示すレジスト等形成パターンは、Ｔ
ＥＯＳ酸化膜４上に、カーボン膜３と、塗布型反射防止
膜としてのポリサルフォンを主成分とする薄膜２と、レ
ジスト１とを順次堆積してなっている。The resist forming pattern shown in FIG.
On the EOS oxide film 4, a carbon film 3, a thin film 2 containing polysulfone as a main component as a coating type antireflection film, and a resist 1 are sequentially deposited.

【００４７】ここで、カーボン膜３とポリサルフォンを
主成分とする薄膜２とによって本実施の形態に係る反射
防止膜５が構成されている。このレジストパターンは以
下のように形成される。Here, the carbon film 3 and the thin film 2 containing polysulfone as a main component constitute the antireflection film 5 according to the present embodiment. This resist pattern is formed as follows.

【００４８】まず、膜厚５０００Ａ（Ａはオングストロ
ームを示す。以下同じ）のＡｌ−Ｓｉ膜上に形成された
ＴＥＯＳ酸化膜４上にカーボン膜３を形成した。カーボ
ン膜３はＡｒ雰囲気中でグラファイト板をターゲットと
したＤＣマグネトロンスパッタリング法を用いることで
作成した。First, a carbon film 3 was formed on a TEOS oxide film 4 formed on an Al-Si film having a film thickness of 5000 A (A indicates angstrom; the same applies hereinafter). The carbon film 3 was formed by using a DC magnetron sputtering method targeting a graphite plate in an Ar atmosphere.

【００４９】形成条件は基板温度２５０℃、圧力４×１
０-3Ｔｏｒｒ、電力密度３．５Ｗ／ｃｍ2 、アルゴン流
量４０ＳＣＣＭである。なお、この形成条件で成膜を行
なったカーボン膜の露光波長λ＝２４８ｎｍでの複素屈
折率はｎ＝１．７８、消衰係数ｋ＝０．６８である。な
お、ポリサルフォンを主成分とする薄膜の複素屈折率は
ｎ＝１．７８、ｋ＝０．２４である。The formation conditions are a substrate temperature of 250 ° C. and a pressure of 4 × 1.
0 -3 Torr, power density 3.5 W / cm 2 , and argon flow rate 40 SCCM. The complex refractive index at the exposure wavelength λ = 248 nm of the carbon film formed under these forming conditions is n = 1.78 and the extinction coefficient k = 0.68. The complex refractive index of the thin film containing polysulfone as a main component is n = 1.78 and k = 0.24.

【００５０】次に、カーボン膜の膜厚の決定方法につい
て述べる。各層での多層反射を考慮して計算したレジス
トとカーボン膜の界面での光反射率を図２に、カーボン
膜の透過率を図３に示す。Next, a method of determining the thickness of the carbon film will be described. FIG. 2 shows the light reflectance at the interface between the resist and the carbon film calculated in consideration of multilayer reflection in each layer, and FIG. 3 shows the transmittance of the carbon film.

【００５１】図２はカーボン膜厚と光反射率の関係を示
す図である。図３はカーボン膜厚と透過率の関係を示す
図である。なお、各実施の形態における各種計算の際に
必要な露光波長での複素屈折率は、分光エリプソにより
測定を行った結果得られた値を用いており、まず、本実
施の形態において必要な複素屈折率を図４に示す。FIG. 2 is a diagram showing the relationship between the carbon film thickness and the light reflectance. FIG. 3 is a diagram showing the relationship between the carbon film thickness and the transmittance. Note that the complex refractive index at the exposure wavelength necessary for various calculations in each embodiment uses a value obtained as a result of measurement by spectroscopic ellipso. The refractive index is shown in FIG.

【００５２】図４は各物質の複素屈折率を示す図であ
る。まず、図３に示すように、カーボンの膜厚が８００
Ａ以上の時、カーボン膜厚に対して反射率が一定となっ
ている。これは、カーボン膜３中で露光光の大部分が吸
収され、カーボン膜３中で多重反射が起こらずカーボン
膜固有の反射率を示しているためである。FIG. 4 is a diagram showing the complex refractive index of each substance. First, as shown in FIG. 3, the carbon film thickness is 800
When A or more, the reflectance is constant with respect to the carbon film thickness. This is because most of the exposure light is absorbed in the carbon film 3, multiple reflection does not occur in the carbon film 3, and the reflectance specific to the carbon film is exhibited.

【００５３】ここで、カーボンの膜厚設定検討のため、
カーボン膜のみを反射防止膜として設け、カーボン膜厚
が８００Ａ及び５２０Ａの場合、カーボン膜上にレジス
トを膜厚５０００Ａで塗布し、後述する［比較例１］の
方法で０．１５μｍのコンタクトホールパターンを形成
しＴＥＯＳ酸化膜の膜厚を７５００〜８５００Ａの範囲
で変化させた時の開孔部の寸法変動量を測定した結果を
図５に示す。Here, in order to study the setting of the carbon film thickness,
When only the carbon film is provided as an antireflection film and the carbon film thickness is 800 A and 520 A, a resist is applied on the carbon film to a film thickness of 5000 A, and a contact hole pattern of 0.15 μm is formed by the method of [Comparative Example 1] described later. FIG. 5 shows the result of measurement of the dimensional variation of the opening when the film thickness of the TEOS oxide film was changed in the range of 7500 to 8500 A by forming the film.

【００５４】図５はカーボン膜を設けたときの０．１５
μｍコンタクトホール寸法のＴＥＯＳ酸化膜膜厚依存性
を示す図である。このとき、膜中で発生した多重反射に
よる（定在波による）寸法変動量を図５に示すように、
すなわち寸法変動量は条件変動（この場合は酸化膜厚変
動）に伴う被加工物の寸法変動（この場合はコンタクト
ホール寸法）であると定義すると、ＴＥＯＳ酸化膜中で
発生した多重反射による寸法変動量は０．０１０μｍ
で、許容範囲（０．０１５μｍ）に収まっていることが
分かる。FIG. 5 shows 0.15 when the carbon film is provided.
It is a figure which shows the TEOS oxide film film thickness dependence of a μm contact hole size. At this time, as shown in FIG. 5, the dimensional variation due to multiple reflections (due to standing waves) generated in the film is
That is, if the amount of dimensional variation is defined as the dimensional variation (contact hole dimension in this case) of the work piece due to the condition variation (in this case, oxide film thickness variation), the dimensional variation due to multiple reflection occurring in the TEOS oxide film. The amount is 0.010 μm
It can be seen that within the allowable range (0.015 μm).

【００５５】これは、図３からも分かるようにカーボン
膜の透過率は８％と低く、ＴＥＯＳ酸化膜中に至る光強
度が無視できるほどの大きさとなるためである。以上の
考察からカーボンの膜３の厚さを８００Ａに設定した。
次に、ポリサルフォンを主成分とする膜２をカーボン膜
３上に塗布し２２０℃で９０秒間ベーキングを行った。
膜厚はレジスト１と反射防止膜５との界面での光強度反
射率を図６に示すように計算して反射率が極小となる３
００Ａとした。This is because, as can be seen from FIG. 3, the transmittance of the carbon film is as low as 8%, and the light intensity reaching the TEOS oxide film is so large that it can be ignored. From the above consideration, the thickness of the carbon film 3 was set to 800A.
Next, the film 2 containing polysulfone as a main component was applied onto the carbon film 3 and baked at 220 ° C. for 90 seconds.
The film thickness is minimized by calculating the light intensity reflectance at the interface between the resist 1 and the antireflection film 5 as shown in FIG.
00A.

【００５６】図６はポリサルフォンを主成分とする膜の
膜厚と光反射率の関係を示す図である。以上のような方
法で反射防止膜５を構成する各層の膜厚の最適化を行
い、反射防止膜５上にポジ型の化学増幅型レジスト１を
膜厚５０００Ａでスピンコーテング法により形成した。FIG. 6 is a diagram showing the relationship between the film thickness of a film containing polysulfone as a main component and the light reflectance. The film thickness of each layer constituting the antireflection film 5 was optimized by the above method, and the positive chemically amplified resist 1 was formed on the antireflection film 5 with a film thickness of 5000 A by the spin coating method.

【００５７】次に、このように形成されたレジストパタ
ーンを用いた場合における半導体装置の製造プロセスの
一つとして、コンタクトホール形成の場合を説明する。
まず、図１に示すレジストパターンに対し、ＫｒＦエキ
シマレーザー光を照射して露光、ついで現像を行い、
０．１５μｍのコンタクトホールを形成する。Next, a case of forming a contact hole will be described as one of the manufacturing processes of a semiconductor device in the case of using the resist pattern thus formed.
First, the resist pattern shown in FIG. 1 is irradiated with KrF excimer laser light for exposure, and then developed,
A contact hole of 0.15 μm is formed.

【００５８】このときの反射防止膜のエッチング方法に
ついて述べる。本実施形態では反射防止膜としてカーボ
ン膜３、ポリサルフォンを主成分とする薄膜２を用いて
おり、両者ともに有機系の物質であるため、レジストを
エッチングする時と同じエッチング条件でエッチングを
行うことができる。A method of etching the antireflection film at this time will be described. In this embodiment, the carbon film 3 and the thin film 2 containing polysulfone as a main component are used as the antireflection film. Since both are organic substances, etching can be performed under the same etching conditions as when etching the resist. it can.

【００５９】その際、エッチング装置には平行平板型の
ＲＩＥ装置を用いた。ガスとしてＣＨＦ3 とＯ2 を２：
３の割合で混ぜたものを用い、圧力、励起電力はそれぞ
れ１０ｍＴｏｒｒ、１．３ｋＷ／ｃｍ2 の条件でエッチ
ングを行った。反射防止膜５のエッチング時の工程を図
７に示す。At that time, a parallel plate type RIE apparatus was used as an etching apparatus. CHF 3 and O 2 as gases 2:
Etching was performed under the conditions of a pressure and an excitation power of 10 mTorr and 1.3 kW / cm 2 , respectively, using a mixture of 3 parts. FIG. 7 shows a process of etching the antireflection film 5.

【００６０】図７は本実施の形態に係るレジストパター
ン形成方法を適用したときのコンタクトホール作成を示
す工程図である。すなわち、同図（ａ）のレジストパタ
ーンに対し、まず同図（ｂ）に示すようにレジスト１の
みをエッチングし、さらに同図（ｃ）に示すように反射
防止膜５をエッチングする。FIG. 7 is a process chart showing the formation of contact holes when the resist pattern forming method according to the present embodiment is applied. That is, with respect to the resist pattern of FIG. 9A, first, only the resist 1 is etched as shown in FIG. 7B, and the antireflection film 5 is further etched as shown in FIG.

【００６１】ここで、エッチング時の寸法精度の問題と
して、反射防止膜５のエッチング終了後、レジストパタ
ーンがテーパー角を有するため、寸法変換差が生じ被加
工物が所望の寸法精度に仕上がらないという問題があ
る。ここで、反射防止膜５のエッチング終了後、生じる
寸法変換差を図７（ｂ），（ｃ）に示すように定義す
る。すなわち、寸法変換差とは、レジスト１のエッチン
グ終了後反射防止膜５エッチング前の寸法ＣＤ１に対す
る反射防止膜５エッチング終了後の寸法ＣＤ２の差を１
／２したものをいう。Here, as a problem of dimensional accuracy at the time of etching, since the resist pattern has a taper angle after the etching of the antireflection film 5, a dimensional conversion difference occurs and the work cannot be finished to a desired dimensional accuracy. There's a problem. Here, the dimensional conversion difference that occurs after etching of the antireflection film 5 is defined as shown in FIGS. 7B and 7C. That is, the dimension conversion difference is a difference between the dimension CD1 after the etching of the resist 1 and before the etching of the antireflection film 5 and the dimension CD2 after the etching of the antireflection film 5 is 1.
/ 2 means what was done.

【００６２】上記説明からわかるように、レジストと被
加工物の間に介在する膜の厚み，この場合は反射防止膜
５が薄いほど寸法変換差がつきにくい。本実施形態の場
合、カーボン膜３とポリサルフォンを主成分とする薄膜
２の膜厚は、それぞれ８００Ａ、３００Ａで合計１１０
０Ａで、エッチング終了後生じた寸法変換差は０．００
８μｍで許容範囲（０．０１μｍ）にあることが分かっ
た。As can be seen from the above description, the smaller the thickness of the film interposed between the resist and the object to be processed, in this case, the thinner the antireflection film 5 is, the smaller the difference in dimensional conversion is. In the case of the present embodiment, the thickness of the carbon film 3 and the thickness of the thin film 2 containing polysulfone as main components are 800 A and 300 A, respectively, which is 110 in total.
At 0 A, the dimensional change after the etching is 0.00
It was found to be within the allowable range (0.01 μm) at 8 μm.

【００６３】反射防止膜５のエッチング終了後、パター
ニングされたレジスト１と反射防止膜５をエッチングマ
スクとしＴＥＯＳ酸化膜４のエッチングを行なった。そ
の際、エッチング装置には平行平板型のＲＩＥ装置を用
いた。ソースガスとしてＣ3Ｆ8 を用い、圧力、励起電
力、ＲＦ周波数はそれぞれ１０ｍＴｏｒｒ、１．３ｋＷ
／ｃｍ2 、１３．５６ＭＨｚの条件でエッチングを行っ
た。After the etching of the antireflection film 5 was completed, the TEOS oxide film 4 was etched using the patterned resist 1 and the antireflection film 5 as etching masks. At that time, a parallel plate type RIE apparatus was used as an etching apparatus. C 3 F 8 was used as a source gas, and pressure, excitation power, and RF frequency were 10 mTorr and 1.3 kW, respectively.
Etching was performed under the conditions of / cm 2 and 13.56 MHz.

【００６４】この時のＴＥＯＳ酸化膜４の開孔部の直径
は０．１６５μｍで、規格内の寸法で被加工物の加工を
行なうことができた。次に、上記パターニング・エッチ
ング方法を用い、ＴＥＯＳ酸化膜４の膜厚を５０００Ａ
に固定し、図８に示すようにレジスト１の膜厚を４５０
０〜５５００Ａの範囲で変化させた時の寸法変動量の測
定を行った。At this time, the diameter of the opening portion of the TEOS oxide film 4 was 0.165 μm, and it was possible to process the work piece within the standard size. Next, using the patterning / etching method described above, the film thickness of the TEOS oxide film 4 is set to 5000A.
Then, as shown in FIG.
The amount of dimensional variation when changing in the range of 0 to 5500 A was measured.

【００６５】図８は本実施の形態に係るレジストパター
ン形成方法を適用したときのコンタクトホールの寸法変
動を示す図である。同図に示すように、本実施の形態の
方法によれば、寸法変動量は０．０１２μｍで許容範囲
内（０．０１５μｍ）に収まっており、レジスト膜中で
発生する多重反射を抑えることができた。なお、比較の
ため、後述する［比較例２］で述べる反射防止膜として
８００Ａのカーボン膜のみを用いた場合を同図に示す。FIG. 8 is a diagram showing the dimensional variation of the contact hole when the resist pattern forming method according to the present embodiment is applied. As shown in the figure, according to the method of the present embodiment, the dimensional variation is 0.012 μm, which is within the allowable range (0.015 μm), and it is possible to suppress the multiple reflection that occurs in the resist film. did it. For comparison, a case where only an 800 A carbon film is used as an antireflection film described in [Comparative Example 2] described later is shown in the same figure.

【００６６】以下、本発明の各実施の形態及び各比較例
での反射防止膜、ＴＥＯＳ酸化膜をエッチングする際の
条件は、エッチング時間を除いて上述した本発明の第１
の実施の形態と同様である。Hereinafter, the conditions for etching the antireflection film and the TEOS oxide film in each embodiment and each comparative example of the present invention are the same as those of the first embodiment of the present invention except the etching time.
This is the same as the embodiment.

【００６７】次に、本実施の形態による方法を評価する
ために、従来技術を用いた比較例について説明する。 ［比較例１］実施形態におけるカーボン膜厚最適化判断
を行うための比較例として、膜厚５２０Ａのカーボン膜
上に膜厚５０００Ａのレジストを形成した場合について
述べる。これは、上述した図５の結果を出すための実験
である。Next, a comparative example using a conventional technique will be described in order to evaluate the method according to the present embodiment. [Comparative Example 1] As a comparative example for determining the optimization of the carbon film thickness in the embodiment, a case will be described in which a 5000A-thick resist is formed on a 520A-thick carbon film. This is an experiment for producing the result of FIG. 5 described above.

【００６８】まず、図２から光反射率はカーボン膜厚が
５２０Ａの時、最少となることが分かる。これは、下地
基板と反射防止膜との界面で反射した光とレジストと反
射防止膜との界面で反射した光が反射防止膜による露光
光の吸収と位相の反転により打ち消されたためである。First, it can be seen from FIG. 2 that the light reflectance is minimum when the carbon film thickness is 520A. This is because the light reflected at the interface between the base substrate and the antireflection film and the light reflected at the interface between the resist and the antireflection film were canceled by the absorption of the exposure light and the phase inversion by the antireflection film.

【００６９】この時、レジストに再入射する光強度の大
きさが最少となるために、レジスト中に発生する多重反
射も最少に抑えられ、レジストの膜厚変動に対する寸法
変動を抑えることが可能となる。At this time, since the intensity of the light re-incident on the resist is minimized, the multiple reflection occurring in the resist is also suppressed to the minimum, and it is possible to suppress the dimensional fluctuation with respect to the fluctuation of the resist film thickness. Become.

【００７０】しかしながら、図３からカーボンの膜厚が
５２０Ａの時、カーボン膜の透過率は２６％と高い。次
に、ＴＥＯＳ酸化膜の膜厚を７５００〜８５００Ａの範
囲で変化させた時の０．１５μｍのコンタクトホールパ
ターンの寸法変動量の測定を行った。However, from FIG. 3, when the carbon film thickness is 520 A, the transmittance of the carbon film is as high as 26%. Next, the dimensional variation of the contact hole pattern of 0.15 μm was measured when the film thickness of the TEOS oxide film was changed in the range of 7500 to 8500A.

【００７１】測定結果を図５に示す。寸法変動量は０．
０２０μｍで、許容範囲（０．０１５μｍ）を越えてい
る。これは、カーボンの膜厚が５２０Ａの場合はカーボ
ンの透過率が高く、ＴＥＯＳ酸化膜中で多重反射が発生
しておりレジストパターンがＴＥＯＳ酸化膜の膜厚変動
の影響を受けやすくなっているためである。The measurement results are shown in FIG. The dimensional variation is 0.
At 020 μm, it exceeds the allowable range (0.015 μm). This is because when the carbon film thickness is 520 A, the carbon transmittance is high, multiple reflection occurs in the TEOS oxide film, and the resist pattern is easily affected by the film thickness variation of the TEOS oxide film. Is.

【００７２】また、同様な条件でカーボンの膜厚が８０
０Ａのときの結果では、寸法変動量が小さくなってい
る。これにより、上述したように、最適なカーボンの膜
厚の判断を行った。Under the same conditions, the carbon film thickness is 80
As a result at 0 A, the amount of dimensional variation is small. As a result, the optimum carbon film thickness was determined as described above.

【００７３】［比較例２］第１の実施の形態に対する比
較例として、膜厚８００Ａのカーボン膜上にレジストを
塗布した場合について述べる。これは上述した図８の結
果を出すための実験である。[Comparative Example 2] As a comparative example to the first embodiment, a case where a resist is applied on a carbon film having a film thickness of 800 A will be described. This is an experiment for producing the results shown in FIG. 8 described above.

【００７４】レジストの膜厚を４５００〜５５００Ａの
範囲で変化させ、０．１５μｍのコンタクトホールパタ
ーンの寸法変動量の測定を行った。測定結果を図８に示
す。レジスト膜中で多重反射が起こっているため寸法変
動量が０．０２０μｍと大きく、許容範囲（０．０１５
μｍ）を越えている。これは、カーボン膜の膜厚が８０
０Ａの時は図２から光反射率は５％と高く、レジスト膜
中で発生した多重反射が抑えられていないためである。The film thickness of the resist was changed in the range of 4500 to 5500 A, and the dimensional variation of the 0.15 μm contact hole pattern was measured. FIG. 8 shows the measurement results. Since multiple reflection occurs in the resist film, the dimensional variation is as large as 0.020 μm, which is within the allowable range (0.015 μm).
μm) is exceeded. This is because the carbon film thickness is 80
This is because at 0 A, the light reflectance is as high as 5% as shown in FIG. 2, and the multiple reflection generated in the resist film is not suppressed.

【００７５】［比較例３］第１の実施の形態に対する比
較例としてポリサルフォンを主成分とする反射防止膜の
みを直接ＴＥＯＳ酸化膜上に形成した場合について述べ
る。[Comparative Example 3] As a comparative example to the first embodiment, a case will be described in which only the antireflection film containing polysulfone as a main component is directly formed on the TEOS oxide film.

【００７６】本発明の第１の実施の形態での考察から、
ＴＥＯＳ酸化膜の膜厚変動がレジストプロファイルに与
える影響を防ぐには、ポリサルフォンを主成分とする反
射防止膜の膜厚をレジストと反射防止膜との界面での反
射率が固有の反射率を示す膜厚に設定し、被加工物内に
光が達しないようにすればよいことが分かる。From the consideration in the first embodiment of the present invention,
In order to prevent the influence of the variation in the film thickness of the TEOS oxide film on the resist profile, the film thickness of the antireflection film containing polysulfone as a main component shows the unique reflectance at the interface between the resist and the antireflection film. It is understood that the film thickness should be set so that the light does not reach the workpiece.

【００７７】レジストと反射防止膜との界面での反射率
を反射防止膜の膜厚に対して計算した結果を図９に示
す。図９はレジストと反射防止膜との界面での反射率を
ポリサルフォンを主成分とする膜のみからなる反射防止
膜の膜厚に対して計算した結果を示す図である。FIG. 9 shows the result of calculation of the reflectance at the interface between the resist and the antireflection film with respect to the film thickness of the antireflection film. FIG. 9 is a diagram showing the results of calculation of the reflectance at the interface between the resist and the antireflection film with respect to the film thickness of the antireflection film composed only of a film containing polysulfone as a main component.

【００７８】同図から２５００Ａ以上の膜厚に設定すれ
ば固有の反射率を示しており、また、この時、レジスト
と反射防止膜との界面での反射率もほとんど無視できる
大きさとなっていることが分かる。From the same figure, when the film thickness is set to 2500 A or more, the specific reflectance is shown, and at this time, the reflectance at the interface between the resist and the antireflection film is also a value that can be almost ignored. I understand.

【００７９】ＴＥＯＳ酸化膜とレジストの膜厚変動に対
するレジストパターンの寸法変動を測定したところ、そ
れぞれ０．０１２μｍ、０．０１４μｍでいずれも許容
範囲（０．０１５μｍ）にあることが分かった。しかし
ながら、反射防止膜の膜厚が２５００Ａと厚いため、本
発明の第１の実施の形態と同じエッチング条件で反射防
止膜のエッチングを行ったところ寸法変換差が０．０１
５ｍで、許容範囲（０．０１μｍ）を越えており所望の
寸法で被加工物の加工ができなかった。When the dimensional variation of the resist pattern with respect to the variation of the film thickness of the TEOS oxide film and the resist was measured, it was found to be 0.012 μm and 0.014 μm, respectively, which were both within the allowable range (0.015 μm). However, since the thickness of the antireflection film is as thick as 2500 A, when the antireflection film is etched under the same etching conditions as in the first embodiment of the present invention, the dimension conversion difference is 0.01.
At 5 m, the allowable range (0.01 μm) was exceeded, and the work piece could not be machined to the desired size.

【００８０】かくして、上述したように本発明の第１の
実施の形態のレジストパターン形成方法によれば、消衰
係数の高いカーボン膜によりＴＥＯＳ酸化膜に入射する
光強度を抑え、消衰係数がカーボン膜よりは低いポリサ
ルフォンを主成分とする反射防止膜をカーボン膜上に形
成することでカーボン膜からレジスト膜中へ反射する光
強度を抑えるようにしたので、つまり、レジスト〜反射
防止膜界面の反射を押さえ、かつレジストから被加工物
に向かって消衰係数が増大するようにしたので、ＴＥＯ
Ｓ酸化膜とレジストの膜厚変動に対して影響を受けない
寸法制御性のよいレジストパターンを得ることが可能と
なった。As described above, according to the resist pattern forming method of the first embodiment of the present invention, the carbon film having a high extinction coefficient suppresses the light intensity incident on the TEOS oxide film, and the extinction coefficient is reduced. Since the antireflection film whose main component is polysulfone, which is lower than the carbon film, is formed on the carbon film to suppress the light intensity reflected from the carbon film into the resist film, that is, at the resist-antireflection film interface. Since the reflection coefficient is suppressed and the extinction coefficient increases from the resist toward the workpiece, TEO
It has become possible to obtain a resist pattern having good dimensional controllability that is not affected by variations in the film thickness of the S oxide film and the resist.

【００８１】なお、ポリサルフォンを主成分とする反射
防止膜のみを被加工物上に形成しても膜中で発生する多
重反射は抑えられるが、本実施形態によれば約２分の１
の膜厚でこれらの条件を満たすことができるため、反射
防止膜のエッチング加工時に生じる寸法変換差をより小
さくすることができる。Even if only the antireflection film containing polysulfone as a main component is formed on the workpiece, the multiple reflection that occurs in the film can be suppressed, but according to this embodiment, it is about half.
Since these conditions can be satisfied by the film thickness of, the dimensional conversion difference generated during the etching process of the antireflection film can be further reduced.

【００８２】すなわち本実施の形態のレジストパターン
形成方法によれば、被加工物からの反射光の抑制が従来
より薄い反射防止膜の膜厚で可能にすることができるの
で、レジスト膜厚の変動、被加工物の種類や膜厚に依存
しないレジストパターンを得ることができ、かつ反射防
止膜のエッチング時に生じる寸法変換差を小さくするこ
とができる。また、エッチング時のレジスト削れを防止
することができる。That is, according to the resist pattern forming method of the present embodiment, it is possible to suppress the reflected light from the object to be processed with the film thickness of the antireflection film which is thinner than the conventional one. It is possible to obtain a resist pattern that does not depend on the type and film thickness of the workpiece, and reduce the dimensional conversion difference that occurs during etching of the antireflection film. Further, it is possible to prevent the resist from being scraped during etching.

【００８３】これにより、規格内の寸法で被加工物の加
工を行なうことができる。また、レジスト及び被加工物
の膜厚変動に伴うレジスト寸法の変動、ハーレーショ
ン、レジストパターンの側壁の波打ち形状等を防ぐこと
ができる。As a result, the work piece can be machined within the standard size. Further, it is possible to prevent fluctuations in resist dimensions due to fluctuations in the film thickness of the resist and the workpiece, halation, and corrugated shapes of the sidewalls of the resist pattern.

【００８４】なお、本実施の形態のレジストパターン形
成方法において、レジスト〜反射防止膜界面の反射防止
膜側の複素屈折率をそのレジスト側への光強度反射率が
極小になるように調整すれば、より一層確実に、レジス
ト膜厚の変動、被加工物の種類や膜厚に依存しないレジ
ストパターンを得ることができる。In the resist pattern forming method of this embodiment, the complex refractive index on the antireflection film side of the resist-antireflection film interface is adjusted so that the light intensity reflectance to the resist side is minimized. Further, it is possible to more reliably obtain a resist pattern that does not depend on variations in the resist film thickness and the type and film thickness of the workpiece.

【００８５】また、以下の実施形態２〜５とその比較例
においてレジスト膜、及びＴＥＯＳ酸化膜中で発生した
多重反射による寸法変動量の許容範囲は、コンタクトホ
ールの直径０．１５μｍの１０％である０．０１５μｍ
とし、反射防止膜のエッチング後に生じる寸法変換差の
許容範囲は約３％である０．０１μｍとした。また、実
施形態２〜５においては、本実施例と同様に膜厚５００
ＡのＡｌ−Ｓｉ膜上にＴＥＯＳ酸化膜、レジストを形成
し、エキシマレーザー光で０．１５μｍのコンタクトホ
ールを形成する。In the following Embodiments 2 to 5 and its comparative example, the permissible range of the dimensional variation due to multiple reflection generated in the resist film and the TEOS oxide film is 10% of the diameter of the contact hole of 0.15 μm. 0.015 μm
The permissible range of the dimensional conversion difference generated after etching the antireflection film was about 3%, ie, 0.01 μm. In addition, in the second to fifth embodiments, the film thickness is 500 as in the present example.
A TEOS oxide film and a resist are formed on the Al-Si film of A, and a 0.15 μm contact hole is formed by excimer laser light.

【００８６】また、何れの実施例でもレジストの膜厚を
変化させた時はＴＥＯＳ酸化膜の膜厚は８０００Ａで固
定し、ＴＥＯＳ酸化膜の膜厚を変化させた時はレジスト
の膜厚は５０００Ａで固定して、ホール寸法を測長し
た。 （発明の第２の実施の形態）本実施の形態に係るレジス
トパターン形成方法においては、その反射防止膜として
２種類の塗布型反射防止膜を露光波長に対して透明な膜
上に形成する。In any of the examples, when the film thickness of the resist was changed, the film thickness of the TEOS oxide film was fixed at 8000 A, and when the film thickness of the TEOS oxide film was changed, the film thickness of the resist was 5000 A. After fixing with, the hole size was measured. (Second Embodiment of the Invention) In the resist pattern forming method according to the present embodiment, two types of coating type antireflection films are formed as antireflection films on a film transparent to an exposure wavelength.

【００８７】本実施の形態に係るレジスト等形成パター
ンは、ＴＥＯＳ酸化膜上に、反射防止膜としてのノボラ
ックを主成分とする膜及びポリサルフォンを主成分とす
る膜を設け、さらにその上にレジストを塗布してなって
いる。The resist or the like forming pattern according to the present embodiment is such that a film containing novolac as a main component as an antireflection film and a film containing polysulfone as a main component are provided on a TEOS oxide film, and a resist is further formed thereon. It has been applied.

【００８８】以下、各膜の形成について説明する。ま
ず、被加工物であるＴＥＯＳ酸化膜上にノボラックを主
成分とする膜を膜厚１１００Ａで塗布し３２０℃で３分
間ベーキングを行った。高温ベーキングした後のノボラ
ックを主成分とする薄膜の露光波長λ＝２４８ｎｍでの
複素屈折率はｎ＝１．７２、ｋ＝０．４６である。The formation of each film will be described below. First, a film containing novolac as a main component was applied at a film thickness of 1100 A on a TEOS oxide film, which is a workpiece, and baked at 320 ° C. for 3 minutes. The complex refractive index at the exposure wavelength λ = 248 nm of the thin film containing novolac as a main component after high temperature baking is n = 1.72 and k = 0.46.

【００８９】次に、ポリサルフォンを主成分とする膜を
膜厚２５０Ａで塗布し２２０℃でベーキングを行った。
なお、ポリサルフォンを主成分とする薄膜の複素屈折率
はｎ＝１．７８、ｋ＝０．２４である。Next, a film containing polysulfone as a main component was applied to a film thickness of 250 A and baked at 220 ° C.
The complex refractive index of the thin film containing polysulfone as a main component is n = 1.78 and k = 0.24.

【００９０】以上の方法で形成した２層の膜からなる反
射防止膜上にレジストを塗布し、ＫｒＦエキシマレーザ
ー光で露光、ついで現像を行い、０．１５μｍのコンタ
クトホールパターンを形成した。A resist was applied on the antireflection film formed of the two-layer film formed by the above method, exposed by KrF excimer laser light, and then developed to form a contact hole pattern of 0.15 μm.

【００９１】なお、ノボラックを主成分とする薄膜、ポ
リサルフォンを主成分とする薄膜の膜厚の決定方法は、
本発明の第１の実施の形態の場合と同様に行った。レジ
ストの膜厚を４５００〜５５００Ａ、ＴＥＯＳ酸化膜の
膜厚を７５００〜８５００Ａの範囲で変化させたときの
ホールパターンの寸法変動量と反射防止膜エッチング加
工跡の寸法変換差を図１０に示す。The method for determining the film thickness of the thin film containing novolac as a main component and the thin film containing polysulfone as a main component is as follows.
The same procedure as in the case of the first embodiment of the present invention was performed. FIG. 10 shows the dimensional variation amount of the hole pattern and the dimensional conversion difference of the antireflection film etching processing trace when the resist film thickness is changed in the range of 4500 to 5500A and the TEOS oxide film film thickness is changed in the range of 7500 to 8500A.

【００９２】図１０は本実施の形態のレジストパターン
形成方法を用いた場合及び用いない場合の各加工寸法を
比較する図である。 ［比較例４］本実施の形態に対する比較例として、反射
防止膜としてポリサルフォンを主成分とする薄膜のみを
用いた場合とノボラックを主成分とする薄膜のみを用い
た場合の寸法変動量と寸法変換差を図１０に示す。FIG. 10 is a diagram for comparing processing dimensions when the resist pattern forming method of the present embodiment is used and when it is not used. [Comparative Example 4] As a comparative example with respect to the present embodiment, the amount of dimensional variation and the size conversion when using only a thin film containing polysulfone as a main component as an antireflection film and using only a thin film containing novolac as a main component. The difference is shown in FIG.

【００９３】それぞれの膜厚はレジスト膜内、又はＴＥ
ＯＳ酸化膜内での多重反射の大きさが小さくなるように
最適化してある。表で寸法変動量、および寸法変換差が
許容範囲（０．０１５μｍ）に収まっている数値につい
ては○印を、許容範囲外のものについては×印をつけて
ある。The respective film thicknesses are within the resist film or TE.
It is optimized so as to reduce the magnitude of multiple reflection in the OS oxide film. In the table, the dimensional variation and the numerical value in which the dimensional conversion difference is within the allowable range (0.015 μm) are marked with a circle, and those outside the allowable range are marked with a cross.

【００９４】かくして、上述したように本発明の第２の
実施の形態のレジストパターン形成方法によれば、ＴＥ
ＯＳ酸化膜上に、消衰係数ｋ＝０．４６のノボラックを
主成分とする膜と、消衰係数ｋ＝０．２４のポリサルフ
ォンを主成分とする膜を順次塗布して、レジスト〜反射
防止膜界面の反射を押さえ、かつレジストから被加工物
に向かって消衰係数が増大するようにしたので、ＴＥＯ
Ｓ酸化膜とレジストの膜厚変動に対して影響を受けない
寸法制御性のよいレジストパターンを得ることができ、
第１の実施の形態と同様な効果を得ることができる。 （発明の第３の実施の形態）本実施の形態に係るレジス
トパターン形成方法においては、カーボン膜を成膜する
際に成膜途中に基板温度を変化させることによって、膜
厚放光で消衰係数の分布をもたせた反射防止膜を露光波
長に対して透明な被加工物上に形成する。As described above, according to the resist pattern forming method of the second embodiment of the present invention, TE
On the OS oxide film, a film containing novolac as the main component with an extinction coefficient k = 0.46 and a film containing polysulfone as the main component with extinction coefficient k = 0.24 are sequentially applied to form resist to antireflection. Since the reflection coefficient at the film interface is suppressed and the extinction coefficient increases from the resist toward the workpiece, TEO
It is possible to obtain a resist pattern having good dimensional controllability that is not affected by variations in the film thickness of the S oxide film and the resist.
The same effect as in the first embodiment can be obtained. (Third Embodiment of the Invention) In the resist pattern forming method according to the present embodiment, when the carbon film is formed, the substrate temperature is changed during the film formation so that the film is extinguished by light emission. An antireflection film having a coefficient distribution is formed on a workpiece that is transparent to the exposure wavelength.

【００９５】本実施の形態に係るレジスト等形成パター
ンは、ＴＥＯＳ酸化膜上に、連続的に複素屈折率（消衰
係数等）の変化する反射防止膜としてのカーボン膜を設
け、さらにその上にレジストを塗布してなっている。In the resist etc. forming pattern according to the present embodiment, a carbon film as an antireflection film having a complex refractive index (extinction coefficient etc.) continuously changing is provided on a TEOS oxide film, and further thereon. It is coated with resist.

【００９６】まず、ＣＶＤ成膜法でカーボン膜の成膜を
行う場合、成膜時の基板温度により複素屈折率が基板温
度により著しく変化する。成膜時の形成条件であるエチ
レンとアルゴンの流量比をそれぞれ４０ＳＣＣＭ、８０
ＳＣＣＭ、励起周波数を１３．５６ＭＨｚ、真空度を２
×１０-3Ｔｏｒｒに固定し、基板温度を室温から３５０
℃まで変えて生成したカーボン膜の成膜を行い、露光波
長λ＝２４８ｎｍでの複素屈折率の測定を行った結果を
図１１に示す。First, when a carbon film is formed by the CVD film forming method, the complex refractive index significantly changes depending on the substrate temperature depending on the substrate temperature at the time of forming the film. The flow rate ratio of ethylene and argon, which is the forming condition at the time of film formation, is 40 SCCM and 80, respectively.
SCCM, excitation frequency 13.56MHz, vacuum degree 2
Fixing at × 10 -3 Torr and substrate temperature from room temperature to 350
FIG. 11 shows the result of measuring the complex refractive index at the exposure wavelength λ = 248 nm by forming a carbon film formed by changing the temperature to ° C.

【００９７】図１１はカーボン膜の露光波長λ＝２４８
ｎｍでの複素屈折率の基板温度依存性を示す図である。
同図によれば基板温度を時間と共に下げれば、被加工物
との界面側からレジストとの界面側に向かってカーボン
膜の消衰係数を徐々に下げることが可能であることが分
かる。そこで、図１２のように基板温度を時間に対して
変化させ、ＴＥＯＳ酸化膜上にカーボン膜の堆積を行
い、カーボン膜の膜厚方向にレジスト側からＴＥＯＳ酸
化膜に向かって消衰係数が増大するように消衰係数に分
布を持たせた。FIG. 11 shows the exposure wavelength of the carbon film λ = 248.
It is a figure which shows the substrate temperature dependence of the complex refractive index in nm.
It can be seen from the figure that the extinction coefficient of the carbon film can be gradually decreased from the interface side with the workpiece to the interface side with the resist by lowering the substrate temperature with time. Therefore, as shown in FIG. 12, the substrate temperature is changed with time to deposit a carbon film on the TEOS oxide film, and the extinction coefficient increases from the resist side to the TEOS oxide film in the film thickness direction of the carbon film. The extinction coefficient has a distribution so that

【００９８】図１２は本実施の形態に係るレジストパタ
ーン形成方法における温度条件を示す図である。なお、
カーボン膜の堆積速度は基板温度には依存せず１００Ａ
／ｍｉｎである。FIG. 12 is a diagram showing temperature conditions in the resist pattern forming method according to the present embodiment. In addition,
The deposition rate of the carbon film does not depend on the substrate temperature and is 100 A
/ Min.

【００９９】以上の方法で形成されたカーボン膜上にレ
ジストを塗布し、ＫｒＦエキシマレーザー光で露光、つ
いで現像を行い、０．１５μｍのコンタクトホールパタ
ーンを形成した。A resist was coated on the carbon film formed by the above method, exposed with KrF excimer laser light, and then developed to form a 0.15 μm contact hole pattern.

【０１００】レジストの膜厚を４５００〜５５００Ａ、
ＴＥＯＳ酸化膜の膜厚を７５００〜８５００Ａの範囲で
変化させたときのホールパターンの寸法変動量とカーボ
ン膜エッチング加工後の寸法変換差を図１３に示す。The film thickness of the resist is 4500-5500A,
FIG. 13 shows the dimensional fluctuation amount of the hole pattern and the dimensional conversion difference after the carbon film etching process when the thickness of the TEOS oxide film was changed in the range of 7500 to 8500A.

【０１０１】図１３は本実施の形態のレジストパターン
形成方法を用いた場合及び用いない場合の各加工寸法を
比較する図である。 ［比較例５］実施例に対する比較例として基板温度を２
５℃に固定した時と３５０℃に固定した時の寸法変動量
と寸法変換差を図１３に示す。それぞれの場合での反射
防止膜の膜厚は、レジスト膜内、又はＴＥＯＳ酸化膜内
での多重反射の大きさが小さくなるように最適化してあ
る。図１３で寸法変動量、および寸法変換差が許容範囲
内に収まっている数値については○印を、許容範囲外の
ものについては×印をつけてある。FIG. 13 is a diagram for comparing processing dimensions when the resist pattern forming method of the present embodiment is used and when it is not used. [Comparative Example 5] As a comparative example to the embodiment, the substrate temperature was set to 2
FIG. 13 shows the amount of dimensional fluctuation and the difference in dimensional conversion when fixed at 5 ° C. and when fixed at 350 ° C. The film thickness of the antireflection film in each case is optimized so as to reduce the magnitude of multiple reflection in the resist film or the TEOS oxide film. In FIG. 13, numerical values for which the dimensional variation and dimensional conversion difference are within the allowable range are marked with a circle, and values outside the allowable range are marked with a cross.

【０１０２】かくして、上述したように本発明の第３の
実施の形態のレジストパターン形成方法によれば、カー
ボン膜中でレジストとの界面側から被加工物との界面側
に向かって連続的に消衰係数を増大させたので、図１３
に示すように、より薄い反射防止膜の膜厚でレジスト膜
厚、ＴＥＯＳ酸化膜の膜厚に対するレジストパターンの
寸法変動量を許容範囲内に収めることができ、寸法変換
差も許容範囲内に収めることができる。As described above, according to the resist pattern forming method of the third embodiment of the present invention, the carbon film is continuously exposed from the interface side with the resist toward the interface side with the workpiece. Since the extinction coefficient was increased, FIG.
As shown in (4), the dimensional variation of the resist pattern with respect to the thickness of the resist film and the thickness of the TEOS oxide film can be kept within the allowable range with a thinner antireflection film, and the dimensional conversion difference can also be kept within the allowable range. be able to.

【０１０３】その結果、規格内の寸法で被加工物の加工
を行なうことができる。また、反射防止膜を多層構造に
することなく、上記効果を得ることができ、この方法に
よれば、少なくとも多層構造にする弊害を排除している
ものと考えられる。なお、第１，第２の実施形態におい
て本実施形態と同等の加工精度を得ている理由は、レジ
スト側の膜にも露光光に対する吸収性のある膜を用いて
いることから、反射防止膜を層間の反射を吸収している
ためと考えられる。 （発明の第４の実施の形態）本実施の形態に係るレジス
トパターン形成方法においては、ＳｉＮ膜を成膜する際
に成膜途中でガスの流量をさせることによって、膜厚方
向で消衰係数に分布をもたせたＳｉＮ膜を露光波長に対
して透明な被加工物上に反射防止膜として形成する。As a result, it is possible to process the work piece within the standard size. Further, the above effect can be obtained without forming the antireflection film in a multilayer structure, and it is considered that this method eliminates at least the adverse effect of forming a multilayer structure. The reason why the processing accuracy equivalent to that of the present embodiment is obtained in the first and second embodiments is that the film on the resist side is also an absorptive film for the exposure light, and therefore the antireflection film is used. Is believed to be due to absorption of reflection between layers. (Fourth Embodiment of the Invention) In the resist pattern forming method according to the present embodiment, when the SiN film is formed, the extinction coefficient in the film thickness direction is set by changing the gas flow rate during the film formation. A SiN film having a distribution is formed as an antireflection film on a workpiece that is transparent to the exposure wavelength.

【０１０４】本実施の形態に係るレジスト等形成パター
ンは、ＴＥＯＳ酸化膜上に、連続的に複素屈折率（消衰
係数等）の変化する反射防止膜としてのＳｉＮ膜を設
け、さらにその上にレジストを塗布してなっている。In the resist etc. forming pattern according to the present embodiment, an SiN film as an antireflection film having a complex refractive index (extinction coefficient etc.) continuously changing is provided on a TEOS oxide film, and further thereon. It is coated with resist.

【０１０５】まず、Ｓｉをターゲットとし基板温度２５
０℃、真空度６×１０-4Ｔｏｒｒ、電力密度３．５ｋＷ
／ｃｍ2 、アルゴンガスの流量を４０ＳＣＣＭとした
時、生成させるＳｉx Ｎ1-x 膜の窒素ガスの流量に対す
る露光波長λ＝２４８ｎｍに対する複素屈折率の変化を
分光エリプソにより測定した結果を図１４に示す。First, with Si as the target, the substrate temperature was set to 25.
0 ℃, vacuum degree 6 × 10 -4 Torr, power density 3.5kW
14 / cm 2 , and the flow rate of the argon gas was 40 SCCM, the change in the complex refractive index with respect to the flow rate of the nitrogen gas in the Si x N 1-x film to be generated with respect to the exposure wavelength λ = 248 nm was measured by a spectroscopic ellipso. Shown in.

【０１０６】図１４はＳｉx Ｎ1-x 膜の窒素ガスの流量
に対する露光波長λ＝２４８ｎｍに対する複素屈折率の
変化を示す図である。同図によれば窒素ガスの流量を増
大させれば消衰係数が減衰し、膜の透明度が増すことが
分かる。FIG. 14 is a diagram showing a change in complex refractive index with respect to the exposure wavelength λ = 248 nm with respect to the flow rate of nitrogen gas in the Si x N 1-x film. According to the figure, it can be seen that when the flow rate of nitrogen gas is increased, the extinction coefficient is attenuated and the transparency of the film is increased.

【０１０７】そこで、始めの１１分間は窒素ガスの流量
を５０ＳＣＣＭとし複素屈折率がｎ＝２．１５、ｋ＝
０．９２の膜を４００Ａの膜厚で成膜し、さらに４分間
窒素ガスの流量を１２０ＳＣＣＭとし複素屈折率がｎ＝
２．０５、ｋ＝０．１２の膜を２００Ａの膜厚で、膜厚
８０００Ａの被加工物であるＴＥＯＳ酸化膜上に成膜し
た。以上のように形成された反射防止膜上にレジストを
塗布し、ＫｒＦエキシマレーザー光で露光、ついで現像
を行い０．１５μｍのコンタクトホールパターンを形成
した。Therefore, for the first 11 minutes, the flow rate of nitrogen gas is set to 50 SCCM and the complex refractive index is n = 2.15, k =
A 0.92 film is formed with a film thickness of 400 A, and the nitrogen gas flow rate is 120 SCCM for 4 minutes, and the complex refractive index is n =
A film having a film thickness of 2.05 and k = 0.12 was formed in a film thickness of 200 A on a TEOS oxide film which was a work piece having a film thickness of 8000 A. A resist was applied on the antireflection film formed as described above, exposed by KrF excimer laser light, and then developed to form a contact hole pattern of 0.15 μm.

【０１０８】レジストの膜厚を４５００〜５５００Ａ、
ＴＥＯＳ酸化膜の膜厚を７５００〜８５００Ａの範囲で
変化させたときのホールパターンの寸法変動量とＳｉx
Ｎ1-x 膜エッチング加工後の寸法変換差を図１５に示
す。The film thickness of the resist is 4500-5500A,
Dimensional variation of the hole pattern and Si x when the thickness of the TEOS oxide film is changed in the range of 7500 to 8500A
FIG. 15 shows the dimensional conversion difference after etching the N 1 -x film.

【０１０９】図１５は本実施の形態のレジストパターン
形成方法を用いた場合及び用いない場合の各加工寸法を
比較する図である。 ［比較例６］本実施の形態に対する比較例として、アル
ゴンガス、窒素の流量をそれぞれ４０ＳＣＣＭ、５０Ｓ
ＣＣＭに固定設定した場合の寸法変動量と寸法変換差を
図１５に示す。それぞれの場合での反射防止膜の膜厚
は、レジスト膜内、又はＴＥＯＳ酸化膜内での多重反射
の大きさが小さくなるように最適化してある。図１５で
寸法変動量、および寸法変換差が許容範囲内である０．
０１５μｍ以内に収まっている数値については○印を、
許容範囲外のものについては×印をつけてある。FIG. 15 is a diagram for comparing the respective processing dimensions with and without the use of the resist pattern forming method of the present embodiment. [Comparative Example 6] As a comparative example to this embodiment, the flow rates of argon gas and nitrogen are 40 SCCM and 50 S, respectively.
FIG. 15 shows the dimensional variation and the dimensional conversion difference when the CCM is fixedly set. The film thickness of the antireflection film in each case is optimized so as to reduce the magnitude of multiple reflection in the resist film or the TEOS oxide film. In FIG. 15, the dimensional fluctuation amount and the dimensional conversion difference are within the allowable range.
For the numerical value within 015 μm, mark ○.
Those outside the allowable range are marked with an X.

【０１１０】かくして、上述したように本発明の第４の
実施の形態のレジストパターン形成方法によれば、Ｓｉ
x Ｎ1-x 膜中でレジスト側から被加工物側に向かって消
衰係数を連続的に増大させたので、図１５に示すよう
に、より薄い反射防止膜の膜厚でレジスト膜厚、ＴＥＯ
Ｓ酸化膜の膜厚に対するレジストパターンの寸法変動量
を許容範囲内に収めることができ、寸法変換差も許容範
囲内に収めることができる。As described above, according to the resist pattern forming method of the fourth embodiment of the present invention, Si
Since the extinction coefficient was continuously increased from the resist side toward the workpiece side in the x N 1-x film, as shown in FIG. TEO
The amount of dimensional variation of the resist pattern with respect to the thickness of the S oxide film can be kept within the allowable range, and the dimensional conversion difference can also be kept within the allowable range.

【０１１１】その結果、所望の寸法に被加工物の加工を
行なうことができる。 （発明の第５の実施の形態）本実施の形態に係るレジス
トパターン形成方法においては、紫外光の照射処理を行
なうことで膜厚方向で消衰係数の分布をもたせた反射防
止膜を露光波長に対して透明な被加工物上に形成する。As a result, the work piece can be machined to a desired size. (Fifth Embodiment of the Invention) In the method for forming a resist pattern according to the present embodiment, an antireflection film having an extinction coefficient distribution in the film thickness direction is exposed to an exposure wavelength by performing irradiation treatment with ultraviolet light. On a work piece that is transparent to.

【０１１２】本実施の形態に係るレジスト等形成パター
ンは、第４の実施の形態の場合と同様に、ＴＥＯＳ酸化
膜上に、連続的に複素屈折率（消衰係数等）の変化する
反射防止膜としてのＳｉＮ膜を設け、さらにその上にレ
ジストを塗布してなっている。As in the case of the fourth embodiment, the resist or the like forming pattern according to the present embodiment has an antireflection property in which the complex refractive index (extinction coefficient etc.) is continuously changed on the TEOS oxide film. A SiN film as a film is provided, and a resist is further applied thereon.

【０１１３】以下、各膜及びコンタクトホールの形成に
ついて説明する。まず、シリコンをターゲットしたＤＣ
スパッタリング装置を用いて、Ｓｉx Ｎ1-x 膜の成膜を
行なった。基板温度２５０℃、真空度６×１０-4Ｔｏｒ
ｒ、電力密度３．５ｋＷ／ｃｍ2 、アルゴンガス、窒素
の流量をそれぞれ４０ＳＣＣＭ、５０ＳＣＣＭに設定
し、ＴＥＯＳ酸化膜上に膜厚４００Ａで堆積を行った。
この形成条件での露光波長λ＝２４８ｎｍでの複素屈折
率は屈折率ｎ＝２．０５、消衰係数ｋ＝０．９２であ
る。The formation of each film and contact hole will be described below. First, DC targeting silicon
A Si x N 1-x film was formed using a sputtering device. Substrate temperature 250 ° C, vacuum degree 6 × 10 -4 Tor
r, power density 3.5 kW / cm 2 , flow rates of argon gas and nitrogen were set to 40 SCCM and 50 SCCM, respectively, and the TEOS oxide film was deposited to a film thickness of 400 A.
The complex refractive index at the exposure wavelength λ = 248 nm under these forming conditions is a refractive index n = 2.05 and an extinction coefficient k = 0.92.

【０１１４】次に、１５０℃でベーキングを行いながら
高圧水銀灯で１分間の紫外線の照射を行い、Ｓｉx Ｎ
1-x 膜の表面を酸化させ消衰係数を低下させた。分光エ
リプソで複素屈折率を測定を行い、表面の酸化が起こっ
た反射防止膜を２層構造とし解析を行なったところ、表
面から２００Ａまでの複素屈折率に変化が見られ、屈折
率ｎ＝２．１５、消衰係数ｋ＝０．１２となっているこ
とが分かった。Next, while baking at 150 ° C., ultraviolet rays are irradiated for 1 minute with a high pressure mercury lamp to give Si x N 2.
The extinction coefficient was lowered by oxidizing the surface of the 1-x film. The complex index of refraction was measured by spectroscopic ellipsometry, and the analysis was performed with a two-layer structure of the antireflection film whose surface was oxidized. As a result, the complex index of refraction from the surface to 200 A was changed, and the index of refraction n = 2. It was found that the extinction coefficient k was 0.15 and the extinction coefficient k was 0.12.

【０１１５】紫外線を照射したＳｉx Ｎ1-x 膜上にレジ
ストを塗布し、ＫｒＦエキシマレーザー光で露光、つい
で現像を行い０．１５μｍのコンタクトホールパターン
を形成した。レジストの膜厚を４５００〜５５００Ａ、
ＴＥＯＳ酸化膜の膜厚を７５００〜８５００Ａの範囲で
変化させたときのホールパターンの寸法変動量とＳｉx
Ｎ1-x 膜エッチング加工後の寸法変換差の結果として、
第４の実施の形態の結果を示す図１５と同様なものが得
られた。A resist was applied on the Si x N 1-x film irradiated with ultraviolet rays, exposed with KrF excimer laser light, and then developed to form a 0.15 μm contact hole pattern. Resist film thickness of 4500-5500A,
Dimensional variation of the hole pattern and Si x when the thickness of the TEOS oxide film is changed in the range of 7500 to 8500A
As a result of the dimensional conversion difference after etching the N 1 -x film,
The same thing as FIG. 15 showing the result of the fourth embodiment was obtained.

【０１１６】かくして、上述したように本発明の第５の
実施の形態のレジストパターン形成方法によれば、Ｓｉ
x Ｎ1-x 膜中でレジスト側から被加工物側に向かって消
衰係数を連続的に増大させたので、より薄い反射防止膜
の膜厚でレジスト膜厚、ＴＥＯＳ酸化膜の膜厚に対する
レジストパターンの寸法変動量を許容範囲内に収めるこ
とができ、寸法変換差も許容範囲内に収めることができ
る。 （発明の第６の実施の形態）本実施の形態に係るレジス
トパターン形成方法においては、その反射防止膜として
２層の反射防止膜を露光波長に対して高反射な被加工物
上に形成する。As described above, according to the resist pattern forming method of the fifth embodiment of the present invention, Si
Since the extinction coefficient was continuously increased from the resist side to the workpiece side in the x N 1-x film, the thinner the thickness of the antireflection film to the thickness of the resist film and the thickness of the TEOS oxide film, The dimensional variation of the resist pattern can be kept within the allowable range, and the dimensional conversion difference can also be kept within the allowable range. (Sixth Embodiment of the Invention) In the resist pattern forming method according to the present embodiment, a two-layer antireflection film is formed as an antireflection film on a workpiece having high reflection with respect to an exposure wavelength. .

【０１１７】本実施の形態に係るレジスト等形成パター
ンは、光反射率の高いＡｌ−Ｓｉ膜上に、露光波長に対
する吸収率の高いＴｉＮ膜を設け、さらにＴｉＮ膜上に
ポリサルフォンを主成分とする膜を設け、当該ＴｉＮ膜
及びポリサルフォンを主成分とする膜を反射防止膜と
し、その上にレジストを塗布してなっている。In the resist or the like forming pattern according to the present embodiment, a TiN film having a high absorptance with respect to an exposure wavelength is provided on an Al-Si film having a high light reflectance, and polysulfone is the main component on the TiN film. A film is provided, the TiN film and the film containing polysulfone as a main component are used as an antireflection film, and a resist is applied thereon.

【０１１８】以下、各膜及びラインアンドスペースの形
成について説明する。まず、膜厚５０００ＡのＡｌ−Ｓ
ｉ膜上にＴｉＮ膜を、窒素雰囲気中でＴｉ板をターゲッ
トとしたＤＣマグネトロンスパッタリング法を用いるこ
とで作成した。形成条件は、基板温度２５０℃、圧力４
×１０-3Ｔｏｒｒ、電力密度３．５Ｗ／ｃｍ2 、アルゴ
ン流量４０ＳＣＣＭ、窒素流量５０ＳＣＣＭである。The formation of each film and line and space will be described below. First, Al-S with a film thickness of 5000 A
A TiN film was formed on the i film by using a DC magnetron sputtering method targeting a Ti plate in a nitrogen atmosphere. The formation conditions are a substrate temperature of 250 ° C. and a pressure of 4
× 10 −3 Torr, power density 3.5 W / cm 2 , argon flow rate 40 SCCM, nitrogen flow rate 50 SCCM.

【０１１９】次に、前記膜上にポリサルフォンを主成分
とする薄膜を塗布し、２２５℃で９０秒間ベーキングを
行った。次に、レジストを塗布しＫｒＦエキシマレーザ
ー光で露光、次いで現像を行いライン寸法０．１５μｍ
のラインアンドスペースパターンを形成した。Next, a thin film containing polysulfone as a main component was applied onto the above film and baked at 225 ° C. for 90 seconds. Next, a resist is applied, exposed with KrF excimer laser light, and then developed to have a line size of 0.15 μm.
Was formed.

【０１２０】ここで、ＴｉＮ膜と有機膜の膜厚の決定方
法について述べる。レジストと有機膜との界面からレジ
スト側に戻る光強度反射率を多重反射を考慮し、ＴｉＮ
膜と有機膜（ポリサルフォンを主成分とする膜）との膜
厚に対して計算をした結果を図１６に示す。Here, a method of determining the film thickness of the TiN film and the organic film will be described. The light intensity reflectance returning from the interface between the resist and the organic film to the resist side is determined by taking TiN
FIG. 16 shows the result of calculation for the film thickness of the film and the organic film (film containing polysulfone as a main component).

【０１２１】図１６は本実施の形態に係るレジストパタ
ーン形成方法に用いる反射防止膜におけるレジストと有
機膜との界面からレジストに戻る光強度反射率を示す図
である。FIG. 16 is a diagram showing the light intensity reflectance returning to the resist from the interface between the resist and the organic film in the antireflection film used in the resist pattern forming method according to this embodiment.

【０１２２】ここで、各層の露光波長に対する複素屈折
率には、分光エリプソにより測定した図４の値を用い
た。なお、なお、ポリサルフォンを主成分とする薄膜の
複素屈折率はｎ＝１．７８、ｋ＝０．２４である。As the complex refractive index of each layer with respect to the exposure wavelength, the value of FIG. 4 measured by spectroscopic ellipsometry was used. The complex refractive index of the thin film containing polysulfone as a main component is n = 1.78 and k = 0.24.

【０１２３】図１６によればＴｉＮ膜の膜厚を１５０
Ａ、有機膜の膜厚を４００Ａにすれば反射率は０．３％
で極小になることが分かった。従って、ＴｉＮ膜の膜厚
は２００Ａ、有機膜の膜厚は４００Ａに決定した。According to FIG. 16, the thickness of the TiN film is set to 150.
A, the reflectance is 0.3% if the film thickness of the organic film is 400A.
It turned out to be a minimum. Therefore, the thickness of the TiN film was determined to be 200A and the thickness of the organic film was determined to be 400A.

【０１２４】レジストの膜厚を４５００〜５５００Ａの
範囲内で変化させレジスト寸法を測定した結果、レジス
ト膜中に発生した多重反射による寸法変動量は０．００
４μｍで許容範囲（０．０１８μｍ）以内にあることが
分かった。レジストと反射防止膜との界面での光反射率
が充分に抑えられているため、レジスト寸法がレジスト
膜厚に対してほとんど変化しないことがわかる。As a result of measuring the resist size by changing the resist film thickness within the range of 4500 to 5500A, the dimensional variation due to multiple reflection occurring in the resist film is 0.00.
It was found that it was within the allowable range (0.018 μm) at 4 μm. It can be seen that the light reflectance at the interface between the resist and the antireflection film is sufficiently suppressed, so that the resist dimension hardly changes with respect to the resist film thickness.

【０１２５】［比較例７］本実施の形態に対する比較例
として、ＴｉＮ膜上に露光波長に対して透明性が高い膜
を形成した場合について述べる。本実施形態と同じ形成
条件で膜厚２００ＡのＴｉＮ膜をＡｌ−Ｓｉ膜上に形成
した。[Comparative Example 7] As a comparative example with respect to the present embodiment, a case will be described in which a film having a high transparency with respect to the exposure wavelength is formed on the TiN film. A TiN film having a film thickness of 200 A was formed on the Al—Si film under the same formation conditions as in the present embodiment.

【０１２６】次に、膜厚１５０ＡのＳｉＮ膜を窒素不雰
囲気中でＴｉ板をターゲットとしたＤＣマグネトロンス
パッタリング法を用いることで作成した。形成条件は、
基板温度２５０℃、圧力４×１０-3Ｔｏｒｒ、電力密度
３．５Ｗ／ｃｍ2 、アルゴン流量４０ＳＣＣＭ、窒素流
量７０ＳＣＣＭである。この形成状態で形成したＳｉＮ
膜の露光波長での複素屈折率はｎ＝２．１０、ｋ＝０．
００３で露光波長に対して透明である。Next, a SiN film having a film thickness of 150 A was formed by using a DC magnetron sputtering method targeting a Ti plate in a non-nitrogen atmosphere. The formation conditions are
The substrate temperature is 250 ° C., the pressure is 4 × 10 −3 Torr, the power density is 3.5 W / cm 2 , the argon flow rate is 40 SCCM, and the nitrogen flow rate is 70 SCCM. SiN formed in this formation state
The complex refractive index of the film at the exposure wavelength is n = 2.10, k = 0.
003 is transparent to the exposure wavelength.

【０１２７】次に、ＴｉＮ膜とＳｉＮ膜の膜厚の決定方
法について述べる。レジストとＳｉＮ膜との界面からの
レジスト側に戻る反射率を、多重反射を考慮し、ＳｉＮ
膜とＴｉＮ膜の膜厚に対して計算した結果を図１７に示
す。Next, a method of determining the film thickness of the TiN film and the SiN film will be described. The reflectivity returning from the interface between the resist and the SiN film to the resist side is determined by taking SiN into consideration.
FIG. 17 shows the calculation result for the film thickness of the film and the TiN film.

【０１２８】図１７はＴｉＮ膜とＳｉＮ膜からなる反射
防止膜における各膜厚に対するレジストとＳｉＮ膜との
界面からレジスト側に戻る光強度反射率を示す図であ
る。同図によればＴｉＮ膜の膜厚を２００Ａ、ＳｉＮ膜
の膜厚を３００Ａ程度の時、反射率が２〜４％で極小と
なることが分かった。従って、ＴｉＮ膜とＳｉＮ膜の膜
厚はそれぞれ２００Ａ、１５０Ａとした。FIG. 17 is a view showing the light intensity reflectance returning from the interface between the resist and the SiN film to the resist side with respect to each film thickness in the antireflection film composed of the TiN film and the SiN film. According to the figure, when the thickness of the TiN film is 200 A and the thickness of the SiN film is about 300 A, the reflectance becomes minimum at 2 to 4%. Therefore, the film thicknesses of the TiN film and the SiN film are set to 200A and 150A, respectively.

【０１２９】次いで、実施例と同様の方法で直径０．１
５μｍのラインアンドスペースパターンを形成した。そ
して、レジストの膜厚を４５００〜５５００Ａの範囲内
で変化させ、レジスト寸法を測定した結果、多重反射に
よる寸法変動量は０．０２０μｍで許容範囲（０．０１
８μｍ）を越えることが分かった。Then, a diameter of 0.1 is obtained in the same manner as in the embodiment.
A line and space pattern of 5 μm was formed. Then, the resist film thickness was changed within the range of 4500 to 5500 A, and the resist size was measured. As a result, the dimensional variation due to multiple reflection was 0.020 μm and was within the allowable range (0.01
8 μm).

【０１３０】本比較例からＴｉＮ膜上に露光波長に対し
て透明性の高い膜を形成した場合、吸収性のある膜を形
成した場合と比較して反射の抑制効果は小さいことが分
かる。From this comparative example, it is understood that the effect of suppressing reflection is smaller when a film having high transparency with respect to the exposure wavelength is formed on the TiN film than when a film having absorptivity is formed.

【０１３１】かくして、上述したように本発明の第６の
実施の形態のレジストパターン形成方法によれば、レジ
ストと反射防止膜との界面における当該反射防止膜を、
露光波長に対して吸収性を有し、かつ界面での露光光反
射を防止する消衰係数を有するポリサルフォンを主成分
とする薄膜とし、さらに、被加工物側に、このポリサル
フォンを主成分とする薄膜よりも露光波長に対する吸収
性が高い膜であるＴｉＮ膜を設けたので、上記第１，第
２の実施の形態と同様な効果を得ることができる他、反
射膜全体としてより一層露光光の吸収を行うことができ
る。As described above, according to the resist pattern forming method of the sixth embodiment of the present invention, the antireflection film at the interface between the resist and the antireflection film is
A thin film containing polysulfone as a main component, which has an extinction coefficient for preventing exposure light reflection at an interface, and which has absorption properties for an exposure wavelength, and further has this polysulfone as a main component on the side of a workpiece. Since the TiN film, which is a film having a higher absorptivity to the exposure wavelength than the thin film, is provided, the same effect as that of the first and second embodiments can be obtained, and the reflection film as a whole has a higher exposure light Can absorb.

【０１３２】このため、反射防止膜全体をより薄くする
ことができ、一層確実に、レジストパターンの寸法変動
量を許容範囲内に収めることができ、寸法変換差も許容
範囲内に収めることができる。Therefore, the entire antireflection film can be made thinner, and the amount of dimensional variation of the resist pattern can be more surely kept within the allowable range, and the dimensional conversion difference can also be kept within the allowable range. .

【０１３３】なお、図１６と図１７との比較からわかる
ことであるが、露光波長に対して吸収性のある膜（本実
施の形態ではポリサルフォン系樹脂）をレジストの直下
に用いた方が、露光波長に対して透明な膜（本実施の形
態ではＳｉＮ膜）をレジストの直下に形成した場合と比
べて、反射防止膜の膜厚変動に対する反射率の変化が小
さい。As can be seen from the comparison between FIG. 16 and FIG. 17, it is better to use a film (polysulfone resin in this embodiment) having absorptivity with respect to the exposure wavelength just below the resist. Compared to the case where a film transparent to the exposure wavelength (SiN film in this embodiment) is formed directly under the resist, the change in reflectance with respect to the film thickness change of the antireflection film is small.

【０１３４】したがって、本発明の第６の実施の形態の
レジストパターン形成方法によれば、露光波長に対して
吸収性を有する膜をレジスト側に設け、さらに、被加工
物側に、この膜よりも露光波長に対する吸収性が高い膜
を設けて反射防止膜としたので、反射防止膜の膜厚に依
存しないレジストパターンを得ることができる。Therefore, according to the resist pattern forming method of the sixth embodiment of the present invention, a film having absorptivity with respect to the exposure wavelength is provided on the resist side, and further, on the workpiece side, the film is formed. Also, since the antireflection film is formed by providing a film having a high absorptivity for the exposure wavelength, it is possible to obtain a resist pattern that does not depend on the film thickness of the antireflection film.

【０１３５】これにより、半導体装置を高歩留まりでか
つ安定して製造することが可能となる。さらに、本発明
の第６の実施の形態のレジストパターン形成方法によれ
ば、上記ポリサルフォンを主成分とする薄膜の厚さとＴ
ｉＮ膜の厚さの組み合わせの中で、露光光のレジスト側
への戻りが極小となり、かつ、反射防止膜全体の厚さを
最も薄くする組み合わせを選択したので、上記各効果を
より一層確実にそうすることができる。This makes it possible to manufacture semiconductor devices with high yield and in a stable manner. Further, according to the resist pattern forming method of the sixth embodiment of the present invention, the thickness and T of the thin film containing polysulfone as the main component and T
Of the combinations of iN film thicknesses, the return of exposure light to the resist side is minimized, and the combination that minimizes the total thickness of the antireflection film is selected, so that each of the above effects can be more reliably achieved. You can do that.

【０１３６】また、上記各実施の形態は、コンタクトホ
ールやラインアンドスペースの形成を例にとって、本発
明に係るレジストパターン形成方法を説明したが、この
ように、当該レジストパターン形成方法を用いた半導体
装置の製造方法を実現することができる。In each of the above embodiments, the resist pattern forming method according to the present invention has been described by taking the formation of the contact hole and the line and space as an example. As described above, the semiconductor using the resist pattern forming method is described. A device manufacturing method can be realized.

【０１３７】さらに、本発明は、上記各実施の形態に限
られない。すなわち、例えば露光光源はＫｒＦエキシマ
レーザー光に限られることはなく、フォトレジストを感
光することができる光源であれば何れでもよい。Furthermore, the present invention is not limited to the above embodiments. That is, for example, the exposure light source is not limited to KrF excimer laser light, and may be any light source that can expose the photoresist.

【０１３８】また、パターン形状はコンタクトホールや
ラインアンドスペースに限定されることなく、本発明の
主旨を逸脱しない限り何にでも適用できる。また、実施
例では被加工物からの反射を抑えた結果、レジストと被
加工物の膜厚変動に伴うレジストパターンの寸法変動の
抑制効果について述べたが、側壁角の波打ち形状の低
減、ＤＯＦの向上、ハーレーションの抑制にも効果があ
る。Further, the pattern shape is not limited to the contact hole and the line and space, and can be applied to anything as long as it does not depart from the gist of the present invention. Further, in the embodiment, as a result of suppressing the reflection from the work piece, the effect of suppressing the dimensional change of the resist pattern due to the film thickness change of the resist and the work piece has been described. It is also effective in improving and suppressing halation.

【０１３９】[0139]

【発明の効果】以上詳記したように本発明によれば、反
射防止膜中の消衰係数を被加工物に向かって増大するよ
うに調整したので、被加工物側からレジスト側への露光
光の反射を極力押さえ、かつ、反射防止膜全体での露光
光吸収効率を高くして反射防止膜を十分に薄くすること
を可能とし、これらにより被加工物の加工精度の高いレ
ジストパターン形成方法及びそのレジストパターン形成
方法を用いた半導体装置の製造方法を提供することがで
きる。As described above in detail, according to the present invention, the extinction coefficient in the antireflection film is adjusted so as to increase toward the workpiece, so that the exposure from the workpiece side to the resist side is performed. A method for forming a resist pattern with high processing accuracy of a work piece by suppressing the reflection of light as much as possible, and increasing the exposure light absorption efficiency of the entire antireflection film to make the antireflection film sufficiently thin. And a method for manufacturing a semiconductor device using the resist pattern forming method.

【図面の簡単な説明】[Brief description of the drawings]

【図１】本発明の第１の実施の形態に係るレジストパタ
ーン形成方法を適用したレジストパターンの一例を示す
構成図。FIG. 1 is a configuration diagram showing an example of a resist pattern to which a resist pattern forming method according to a first embodiment of the present invention is applied.

【図２】カーボン膜厚と光反射率の関係を示す図。FIG. 2 is a diagram showing the relationship between carbon film thickness and light reflectance.

【図３】カーボン膜厚と透過率の関係を示す図。FIG. 3 is a graph showing the relationship between carbon film thickness and transmittance.

【図４】各物質の複素屈折率を示す図。FIG. 4 is a diagram showing the complex refractive index of each substance.

【図５】カーボン膜を設けたときの０．１５μｍコンタ
クトホール寸法のＴＥＯＳ酸化膜膜厚依存性を示す図。FIG. 5 is a diagram showing the TEOS oxide film thickness dependence of the 0.15 μm contact hole size when a carbon film is provided.

【図６】ポリサルフォンを主成分とする膜の膜厚と光反
射率の関係を示す図。FIG. 6 is a diagram showing a relationship between a film thickness of a film containing polysulfone as a main component and light reflectance.

【図７】本実施の形態に係るレジストパターン形成方法
を適用したときのコンタクトホール作成を示す工程図。FIG. 7 is a process chart showing the formation of contact holes when the resist pattern forming method according to the present embodiment is applied.

【図８】本実施の形態に係るレジストパターン形成方法
を適用したときのコンタクトホールの寸法変動を示す
図。FIG. 8 is a diagram showing dimensional variation of a contact hole when the resist pattern forming method according to the present embodiment is applied.

【図９】レジストと反射防止膜との界面での反射率をポ
リサルフォンを主成分とする膜のみからなる反射防止膜
の膜厚に対して計算した結果を示す図。FIG. 9 is a diagram showing a result of calculating reflectance at an interface between a resist and an antireflection film with respect to a film thickness of an antireflection film composed only of a film containing polysulfone as a main component.

【図１０】本発明の第２の実施の形態のレジストパター
ン形成方法を用いた場合及び用いない場合の各加工寸法
を比較する図。FIG. 10 is a diagram comparing respective processing dimensions with and without the use of the resist pattern forming method according to the second embodiment of the present invention.

【図１１】カーボン膜の露光波長λ＝２４８ｎｍでの複
素屈折率の基板温度依存性を示す図。FIG. 11 is a diagram showing the substrate temperature dependence of the complex refractive index of the carbon film at the exposure wavelength λ = 248 nm.

【図１２】本発明の第３の実施の形態に係るレジストパ
ターン形成方法における温度条件を示す図。FIG. 12 is a diagram showing temperature conditions in a resist pattern forming method according to a third embodiment of the present invention.

【図１３】同実施の形態のレジストパターン形成方法を
用いた場合及び用いない場合の各加工寸法を比較する
図。FIG. 13 is a diagram comparing processing dimensions when the resist pattern forming method of the same embodiment is used and when it is not used.

【図１４】Ｓｉx Ｎ1-x 膜の窒素ガスの流量に対する露
光波長λ＝２４８ｎｍに対する複素屈折率の変化を示す
図。FIG. 14 is a diagram showing a change in complex refractive index with respect to an exposure wavelength λ = 248 nm with respect to a flow rate of nitrogen gas in a Si x N 1-x film.

【図１５】本発明の第４の実施の形態のレジストパター
ン形成方法を用いた場合及び用いない場合の各加工寸法
を比較する図。FIG. 15 is a diagram comparing processing dimensions when a resist pattern forming method according to a fourth embodiment of the present invention is used and when it is not used.

【図１６】本発明の第６の実施の形態に係るレジストパ
ターン形成方法に用いる反射防止膜におけるレジストと
有機膜との界面からレジストに戻る光強度反射率を示す
図。FIG. 16 is a diagram showing the light intensity reflectance returning from the interface between the resist and the organic film in the antireflection film used in the resist pattern forming method according to the sixth embodiment of the present invention to the resist.

【図１７】ＴｉＮ膜とＳｉＮ膜からなる反射防止膜にお
ける各膜厚に対するレジストとＳｉＮ膜との界面からレ
ジスト側に戻る光強度反射率を示す図。FIG. 17 is a diagram showing the light intensity reflectance returning from the interface between the resist and the SiN film to the resist side with respect to each film thickness in the antireflection film composed of the TiN film and the SiN film.

【符号の説明】[Explanation of symbols]

１…レジスト、２…ポリサルフォンを主成分とする薄
膜、３…カーボン膜、４…ＴＥＯＳ酸化膜、５…反射防
止膜。1 ... Resist, 2 ... Thin film containing polysulfone as a main component, 3 ... Carbon film, 4 ... TEOS oxide film, 5 ... Antireflection film.

Claims (5)

【特許請求の範囲】[Claims] 【請求項１】 被加工物上に反射防止膜、レジストを順
次形成し、前記レジストを選択的に露光、現像を行いレ
ジストパターンを形成するレジストパターン形成方法に
おいて、 当該反射防止膜の消衰係数を前記レジストとの界面側か
ら前記被加工物との界面側に向って増大するように設定
することを特徴とするレジストパターン形成方法。1. An extinction coefficient of an antireflection film in a method of forming a resist pattern, in which an antireflection film and a resist are sequentially formed on a workpiece and the resist is selectively exposed and developed to form a resist pattern. Is set so as to increase from the interface side with the resist toward the interface side with the object to be processed. 【請求項２】 前記反射防止膜の消衰係数を前記レジス
トとの界面側から前記被加工物との界面側に向って連続
的に増大するような部分を少なくとも設けることを特徴
とする請求項１記載のレジストパターン形成方法。2. An at least part is provided so that the extinction coefficient of the antireflection film continuously increases from the interface side with the resist toward the interface side with the workpiece. 1. The method for forming a resist pattern according to 1. 【請求項３】 被加工物上に反射防止膜、レジストを順
次形成し、前記レジストを選択的に露光、現像を行いレ
ジストパターンを形成するレジストパターン形成方法に
おいて、 前記反射防止膜は、前記レジストと接する第１の膜と、
前記被加工物と接する第２の膜との少なくとも２層から
なり、 前記第１の膜は、前記レジストと前記反射防止膜との界
面における当該反射防止膜の露光波長に対する消衰係数
を、前記露光波長に対して吸収性を有し、かつ前記界面
での露光光反射を防止する大きさとし、 前記第２の膜は、前記第１の膜よりも前記露光波長に対
する吸収性が高い膜とすることを特徴とするレジストパ
ターン形成方法。3. A resist pattern forming method for forming a resist pattern by sequentially forming an antireflection film and a resist on a workpiece and selectively exposing and developing the resist, wherein the antireflection film is the resist. A first film in contact with
At least two layers of a second film in contact with the work piece are formed, and the first film has an extinction coefficient for an exposure wavelength of the antireflection film at an interface between the resist and the antireflection film, The film has an absorption property with respect to the exposure wavelength and a size that prevents exposure light reflection at the interface, and the second film has a higher absorption property with respect to the exposure wavelength than the first film. A method of forming a resist pattern, comprising: 【請求項４】 前記第１の膜の厚さと前記第２の膜の厚
さの組み合わせの中で、露光光の前記レジスト側への戻
りが極小となり、かつ、反射防止膜全体の厚さを最も薄
くする前記組み合わせを選択することを特徴とする請求
項３記載のレジストパターン形成方法。4. In the combination of the thickness of the first film and the thickness of the second film, the return of exposure light to the resist side is minimized, and the total thickness of the antireflection film is reduced. 4. The resist pattern forming method according to claim 3, wherein the combination that makes the thinnest is selected. 【請求項５】 請求項１乃至４のうち、何れか１項記載
のレジストパターン形成方法を用いた半導体装置の製造
方法。5. A method of manufacturing a semiconductor device using the resist pattern forming method according to claim 1.
JP33332495A 1995-12-21 1995-12-21 Formation of resist pattern and production of semiconductor device employing it Pending JPH09171952A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP33332495A JPH09171952A (en) 1995-12-21 1995-12-21 Formation of resist pattern and production of semiconductor device employing it

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP33332495A JPH09171952A (en) 1995-12-21 1995-12-21 Formation of resist pattern and production of semiconductor device employing it

Publications (1)

Publication Number Publication Date
JPH09171952A true JPH09171952A (en) 1997-06-30

Family

ID=18264842

Family Applications (1)

Application Number Title Priority Date Filing Date
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Country Link
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