JPH09189990A - Mask for exposure - Google Patents
Mask for exposureInfo
- Publication number
- JPH09189990A JPH09189990A JP162696A JP162696A JPH09189990A JP H09189990 A JPH09189990 A JP H09189990A JP 162696 A JP162696 A JP 162696A JP 162696 A JP162696 A JP 162696A JP H09189990 A JPH09189990 A JP H09189990A
- Authority
- JP
- Japan
- Prior art keywords
- film
- phase shift
- substance
- exposure
- irradiation
- 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
Links
Landscapes
- Exposure Of Semiconductors, Excluding Electron Or Ion Beam Exposure (AREA)
- Preparing Plates And Mask In Photomechanical Process (AREA)
- Exposure And Positioning Against Photoresist Photosensitive Materials (AREA)
Abstract
Description
【0001】[0001]
【発明の属する技術分野】本発明は、半導体産業等で用
いられているリソグラフィ技術に係わり、特に位相シフ
ト膜を用いた露光用マスクの改良に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lithography technique used in the semiconductor industry or the like, and more particularly to improvement of an exposure mask using a phase shift film.
【0002】[0002]
【従来の技術】近年、半導体産業ではLSIの高集積化
に伴って、益々微細なパターンを作成していくことが要
求されている。これを実現するには、リソグラフィにお
ける分解能の向上が必要であり、その一手法として位相
シフト法が提案されている。2. Description of the Related Art Recently, in the semiconductor industry, with the high integration of LSIs, it is required to create finer patterns. In order to realize this, it is necessary to improve the resolution in lithography, and a phase shift method has been proposed as one of the methods.
【0003】また、リソグラフィの分解能が波長に比例
するため、微細なパターンを形成していくために露光光
源波長をより短くしていく方向にある。1GビットDR
AMに対しては0.2μm、4GビットDRAMに対し
ては0.1μm程度の微細パターンが要求されており、
これらのパターンの実現にはKrF(248nm)或い
はそれ以下の波長の光源を露光の際に用いる必要があ
る。Since the resolution of lithography is proportional to the wavelength, the wavelength of the exposure light source tends to be shortened in order to form a fine pattern. 1G bit DR
A fine pattern of about 0.2 μm for AM and about 0.1 μm for 4 Gbit DRAM is required.
In order to realize these patterns, it is necessary to use a light source having a wavelength of KrF (248 nm) or shorter at the time of exposure.
【0004】このような露光光源の短波長化により今後
は、より多大なエネルギーが位相シフトマスクに照射さ
れる。位相シフトマスクに大きなエネルギーが照射され
ると、マスク材料(位相シフト膜)に酸化反応等が生
じ、位相シフト膜の光学特性(屈折率,消衰係数)等が
変化する。位相シフト膜の光学特性が変化すると、透過
率,位相差が変化し、焦点深度の劣化を招く。つまり、
短波長光の照射により位相シフト膜の光学特性等が変化
し、露光前に設定された所望の透過率,位相差が変化
し、焦点深度の劣化を引き起こすことが問題となってい
る。Due to such shortening of the wavelength of the exposure light source, much more energy will be applied to the phase shift mask in the future. When the phase shift mask is irradiated with a large amount of energy, an oxidation reaction or the like occurs in the mask material (phase shift film), and the optical characteristics (refractive index, extinction coefficient) and the like of the phase shift film change. When the optical characteristics of the phase shift film change, the transmittance and the phase difference change, which causes the depth of focus to deteriorate. That is,
Irradiation with short-wavelength light changes the optical characteristics of the phase shift film, changes desired transmittance and phase difference set before exposure, and causes deterioration of the depth of focus.
【0005】本発明者らは、露光時の光学特性の変化を
抑えるために光,熱,反応ガスを用いた処理を行い、位
相シフト膜を光学的に安定にする手法を提案してきた
(特開平7−104457号公報)。しかし、これらの
手法では、膜作成後に行うUV光照射又は加熱処理で生
じる光学定数の変化を予め見込んで位相シフト膜を作成
する必要が生じる。このことは、最終的に所望の透過
率,位相差を持った膜であるかの判断を困難にしてい
る。また、膜作成後にUV光照射を行うという新たな処
理が加わり、工程数が増加するという問題もあった。The present inventors have proposed a method of optically stabilizing a phase shift film by performing a treatment using light, heat, and a reaction gas in order to suppress a change in optical characteristics during exposure (special feature: Kaihei 7-104457). However, in these methods, it is necessary to prepare a phase shift film in consideration of changes in optical constants caused by UV light irradiation or heat treatment performed after film formation. This makes it difficult to finally determine whether the film has the desired transmittance and phase difference. In addition, there is a problem that a new process of irradiating UV light after forming the film is added and the number of steps is increased.
【0006】位相シフトマスクにおいては露光光の透過
率,位相は非常に重要なパラメータである。透過率,位
相の経時変化は、位相シフトマスクの性能を劣化させ、
焦点深度の減少やパターン寸法の変動などデバイス作成
で大きな問題となっていた。このため、上記のUV光照
射処理を行わずに透過率,位相差を確認でき、かつ露光
時の位相シフト膜の光学定数を補償できる方法が望まれ
ていた。In the phase shift mask, the transmittance and phase of exposure light are very important parameters. The change in transmittance and phase with time deteriorates the performance of the phase shift mask,
There have been major problems in device fabrication such as reduction of depth of focus and fluctuations in pattern dimensions. Therefore, there has been a demand for a method capable of confirming the transmittance and the phase difference without performing the UV light irradiation treatment and compensating the optical constant of the phase shift film at the time of exposure.
【0007】[0007]
【発明が解決しようとする課題】このように従来、位相
シフト膜を用いた位相シフトマスクにおいては、露光時
に生じる酸化反応等により位相シフト膜の光学定数が変
化し、焦点深度の劣化やパターン寸法の変動等を招く問
題があった。As described above, in the conventional phase shift mask using the phase shift film, the optical constant of the phase shift film changes due to the oxidation reaction or the like that occurs at the time of exposure, resulting in deterioration of the depth of focus and pattern size. There was a problem of causing fluctuations in
【0008】本発明は、上記事情を考慮して成されたも
ので、その目的とするところは、露光光照射に対する位
相シフト膜の透過率,位相差の変動を抑制することがで
き、焦点深度の劣化やパターン寸法の変動等を防止し得
る露光用マスクを提供することにある。The present invention has been made in consideration of the above circumstances, and an object thereof is to suppress fluctuations in the transmittance and phase difference of a phase shift film with respect to exposure light irradiation, and to reduce the depth of focus. Another object of the present invention is to provide an exposure mask capable of preventing the deterioration of the pattern and the variation of the pattern dimension.
【0009】[0009]
(構成)上記課題を解決するために本発明は、次のよう
な構成を採用している。即ち本発明は、透光性基板上に
少なくとも位相シフト膜からなるパターンを有する露光
用マスクにおいて、前記位相シフト膜は、露光光照射に
よって光学定数に変化が生じる第1の物質に、前記露光
光照射によって第1の物質とは異なる光学定数変化が生
じる第2の物質を添加又は混合して形成されてなること
を特徴とする。(Structure) In order to solve the above problem, the present invention employs the following structure. That is, the present invention relates to an exposure mask having a pattern composed of at least a phase shift film on a transparent substrate, wherein the phase shift film is the first substance whose optical constant changes due to exposure light irradiation. It is characterized in that it is formed by adding or mixing a second substance that causes a change in optical constant different from that of the first substance by irradiation.
【0010】ここで、本発明の望ましい実施態様として
は、次のものがあげられる。 (1) 第1の物質と第2の物質における光学定数の変化
は、前記露光光照射による屈折率,消衰係数に関する増
減が相反する方向であること。 (2) 第1の物質と第2の物質における光学定数の変化
は、光重合,光酸化又は光分解により引き起こされるも
のであること。 (3) 第1の物質はSiNx 又はSiNx Oy であり、第
2の物質はTiであること。 (4) 第1の物質に対する第2の物質の添加又は混合量
は、前記位相シフト膜の屈折率及び消衰係数の少なくと
も一方が露光光照射によっても変化しないように設定さ
れること。 (作用)まず、光のエネルギーについて説明する。光の
持つエネルギーEは、その波長λと次のような関係があ
る。Here, preferred embodiments of the present invention include the following. (1) Changes in the optical constants of the first substance and the second substance should be such that the increase and decrease in the refractive index and the extinction coefficient due to the exposure light irradiation are in opposite directions. (2) Changes in the optical constants of the first substance and the second substance must be caused by photopolymerization, photooxidation or photolysis. (3) The first substance is SiNx or SiNxOy, and the second substance is Ti. (4) The addition amount or the mixing amount of the second substance with respect to the first substance should be set so that at least one of the refractive index and the extinction coefficient of the phase shift film does not change even when exposed to exposure light. (Operation) First, the energy of light will be described. The energy E of light has the following relationship with the wavelength λ.
【0011】E=hc/λ h:プランク定数(6.626×10-26 J・sec ) c:光速(2.998×1010cm/sec) 例えば、波長365nmの光のエネルギーは約78 kca
l/mol であり、波長248nmのKrFエキシマレーザ
では約115 kcal/mol 、波長193nmでは約148
kcal/mol となる。このように現在又は将来LSIを作
成するために用いられる光源は非常に高いエネルギーを
有していることが分る。E = hc / λ h: Planck's constant (6.626 × 10 −26 J · sec) c: Speed of light (2.998 × 10 10 cm / sec) For example, the energy of light having a wavelength of 365 nm is about 78 kca.
l / mol, about 115 kcal / mol for a KrF excimer laser with a wavelength of 248 nm, and about 148 for a wavelength of 193 nm.
It becomes kcal / mol. As described above, it can be seen that the light source used for producing the present or future LSI has very high energy.
【0012】特に、短波長光による照射時は、雰囲気中
に酸素分子がある場合、この光により酸素分子が酸素ラ
ジカルO( 1D)やO( 3P)に分解される。また同時
に、2次元反応によりオゾン(O3 )が生成されるた
め、酸化による位相シフト膜の物質変化が起きやすい。
この発生した酸素ラジカルO( 1D)は、他の酸素ラジ
カルに対して活性であり、酸化反応に有効に働く。In particular, during irradiation with short-wavelength light, if oxygen molecules are present in the atmosphere, the light decomposes the oxygen molecules into oxygen radicals O ( 1 D) and O ( 3 P). At the same time, ozone (O 3 ) is generated by the two-dimensional reaction, so that the substance of the phase shift film is likely to change due to oxidation.
The generated oxygen radical O ( 1 D) is active with respect to other oxygen radicals and effectively acts on the oxidation reaction.
【0013】次に、元素の化学結合エネルギーを、下記
の(表1)に示す。殆どの結合エネルギーはランプで放
出される光のエネルギー以下であるため、大半の弱い結
合について上記の光照射により解離され、より強い結合
状態へと再結合することが可能である。このため、光源
の短波長に伴い、酸化反応等による位相シフト膜の光学
定数変化が起こる。Next, the chemical bond energies of the elements are shown in the following (Table 1). Since most of the binding energy is less than the energy of the light emitted from the lamp, most of the weak bonds can be dissociated by the above light irradiation and can be recombined into a stronger bonding state. Therefore, the optical constant of the phase shift film changes due to the oxidation reaction or the like with the short wavelength of the light source.
【0014】[0014]
【表1】 [Table 1]
【0015】例えば、位相シフト膜の材料であるSiN
x 膜の場合、窒素の孤立電子対を酸素ラジカルが酸化し
新たな強い結合を作るために、短波長光での露光の最、
光学定数が変化する。このときの上記SiNx の酸化に
よる光学定数の変化は、KrFエキシマレーザ波長(2
48nm)において屈折率,消衰係数共に酸化により減
少することが分っている。For example, SiN which is the material of the phase shift film
In the case of the x film, in order to oxidize the lone electron pair of nitrogen by the oxygen radical and form a new strong bond, at the time of exposure with short wavelength light,
The optical constant changes. At this time, the change of the optical constant due to the oxidation of SiNx is caused by the KrF excimer laser wavelength (2
It has been found that both the refractive index and the extinction coefficient at 48 nm) decrease due to oxidation.
【0016】上記のような光学定数の変動を抑制するに
は、このような位相シフト膜の光学定数変化とは逆の変
化をするような物質を位相シフト膜中に添加又は混合し
て、全体としての光学定数の変化を補償すればよい。こ
のことを、図1に示す。この図では、互いに相殺しあう
2つの物質を第1の化合物、第2の化合物と称してい
る。このように、例えば波長248nmで屈折率・消衰
係数が例えば酸化によって減少する物質(第1の化合
物)に、同じ波長で屈折率・消衰係数が例えば酸化によ
って増加するような物質(第2の化合物)を添加するこ
とで、露光時における透過率,位相差の変化を抑制する
ことが可能である。In order to suppress the fluctuation of the optical constants as described above, a substance that causes a change opposite to the change of the optical constants of the phase shift film is added or mixed into the phase shift film, and the whole is changed. It suffices to compensate for the change in the optical constant. This is shown in FIG. In this figure, two substances that cancel each other out are called a first compound and a second compound. Thus, for example, a substance whose refractive index / extinction coefficient decreases at a wavelength of 248 nm (first compound), for example, is added to a substance whose refractive index / extinction coefficient increases at the same wavelength, for example, by oxidation (second compound). It is possible to suppress changes in transmittance and retardation during exposure by adding the compound).
【0017】また、互いに光学定数を相殺し合う組み合
わせを図2に示す。図2中の(a)は消衰係数kは一定
で屈折率nが変化する例、(b)は消衰係数kは一定で
屈折率nが変化する例、(c)(d)は消衰係数k及び
屈折率nが共に変化する例である。ここで、図1及び図
2では露光前後の光学定数変化を直線的に示したが、こ
れは曲線でもよく途中の経過は問わない。FIG. 2 shows a combination for canceling the optical constants. 2A shows an example in which the extinction coefficient k is constant and the refractive index n changes, FIG. 2B shows an example in which the extinction coefficient k is constant and the refractive index n changes, and FIGS. This is an example in which both the extinction coefficient k and the refractive index n change. Here, in FIGS. 1 and 2, the change in the optical constants before and after the exposure is shown linearly, but this may be a curve, and the course in the middle does not matter.
【0018】上記の一例は、SiNx 中にTiを均一に
添加することで達成される。具体的な光学定数の変化を
図3に示す。SiNx 膜中におけるSiの光酸化で生じ
るSiO2 への光学定数の変化は図中丸印で示すよう
に、消衰係数k,屈折率n共に減少する方向であるが、
Tiの光酸化で生じるTiOへの光学定数の変化は図中
三角印で示すように、消衰係数k,屈折率n共に増加す
る方向である。従って、SiNx 中にTiを添加するこ
とにより、露光前後における光学定数(屈折率,消衰係
数)の変動が抑制される。SiNx の代わりにSiNx
Oy を用いても同様である。The above example is achieved by uniformly adding Ti into SiNx. A concrete change of the optical constant is shown in FIG. As shown by the circles in the figure, changes in the optical constants of SiO 2 caused by the photooxidation of Si in the SiNx film tend to decrease both the extinction coefficient k and the refractive index n.
The change of the optical constant to TiO caused by the photooxidation of Ti is such that both the extinction coefficient k and the refractive index n increase as indicated by the triangle marks in the figure. Therefore, by adding Ti to SiNx, fluctuations in optical constants (refractive index, extinction coefficient) before and after exposure are suppressed. SiNx instead of SiNx
The same applies when Oy is used.
【0019】例えば、SiNx にTiを11%(θ=
0.11)ドープして作成したSiNx Oy Tiz 膜
(x=0.87,y=0.01,z=0.11)では、
波長248nmの光照射前後での光学定数は以下のよう
になった。但し、膜厚は104.7nmで作成した。即
ち、 照射前:2.213−0.585i 照射後:2.212−0.557i このとき、光照射前後での透過率変化は3.94%から
4.59%、位相の変化は179.9度から180.0
度であった。For example, 11% of Ti is added to SiNx (θ =
0.11) In the SiNx Oy Tiz film (x = 0.87, y = 0.01, z = 0.11) formed by doping,
The optical constants before and after irradiation with light having a wavelength of 248 nm are as follows. However, the film thickness was 104.7 nm. That is, before irradiation: 2.213-0.585i After irradiation: 2.212-0.557i At this time, the transmittance change before and after the light irradiation was 3.94% to 4.59%, and the phase change was 179. 9 degrees to 180.0
Degree.
【0020】一方、Tiを添加しないSiNx Oy (x
=0.57,y=0.25)の場合、照射前後での屈折
率,消衰係数は以下のようになった。但し、膜厚は10
1.7nmで作成した。即ち、 照射前:2.25−0.60i 照射後:2.15−0.45i これにより、SiNx Oy では照射前に透過率3.95
%、位相差180度であったものが、照射後に透過率
8.78%、位相差166.1度と大きく変化してい
た。従って、SiNx Oy にTiをドープすることによ
り、光照射前後での透過率,位相差の変動を大幅に小さ
くすることができた。On the other hand, SiNx Oy (x
= 0.57, y = 0.25), the refractive index and extinction coefficient before and after irradiation were as follows. However, the film thickness is 10
It was created at 1.7 nm. That is, before irradiation: 2.25-0.60i After irradiation: 2.15-0.45i Therefore, the transmittance of SiNx Oy before irradiation is 3.95.
%, The phase difference was 180 degrees, but the transmittance was 8.78% and the phase difference was 166.1 degrees after irradiation. Therefore, by doping SiNxOy with Ti, it was possible to greatly reduce the fluctuations in the transmittance and the phase difference before and after the light irradiation.
【0021】また、上記ではSiNx Oy を例として取
り上げたが、他にもMo,Cr,Fe,Hf等の遷移元
素又はこれらのシリサイドの酸化物,窒化物,水素化
物,炭化物,ハロゲン化物,及びこれらの混合物などに
対しても上記手法により露光時の透過率,位相差の変動
を抑制することが可能である。Although SiNx Oy is taken as an example in the above, other transition elements such as Mo, Cr, Fe and Hf or oxides, nitrides, hydrides, carbides, halides of these silicides, and With respect to these mixtures and the like, it is possible to suppress the fluctuation of the transmittance and the phase difference at the time of exposure by the above method.
【0022】また、上記では酸化に伴う位相シフト膜の
光学定数変化を相殺するよう調整したが、これに限らず
他のガス等による光学定数変化を相殺するように添加す
る材料を選択することも可能である。以下に、第1の化
合物と第2の化合物の具体的な組み合わせについて示
す。Further, in the above, the adjustment was made so as to cancel the change in the optical constant of the phase shift film due to the oxidation, but the present invention is not limited to this, and a material to be added may be selected so as to cancel the change in the optical constant due to another gas or the like. It is possible. The specific combinations of the first compound and the second compound are shown below.
【0023】第1の化合物としては、SiNx ,SiO
x ,SiNx Oy ,MoSiOx ,MoSiNx ,Mo
SiNx Oy ,CrOx ,CrFx ,CrNx ,CrN
x Oy があり、第2の化合物としてはTi若しくはTi
を含む化合物がある。As the first compound, SiNx, SiO
x, SiNx Oy, MoSiOx, MoSiNx, Mo
SiNx Oy, CrOx, CrFx, CrNx, CrN
x Oy, and the second compound is Ti or Ti
There are compounds containing.
【0024】[0024]
【発明の実施の形態】以下、本発明の詳細を図示の実施
形態によって説明する。本実施形態では、KrFエキシ
マレーザ露光に用いるSiNx Oy Tiz 位相シフト膜
について説明する。図4は、本発明の一実施形態に係わ
る露光用マスクの製造工程を示す断面図である。DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The details of the present invention will be described below with reference to the illustrated embodiments. In this embodiment, a SiNx Oy Tiz phase shift film used for KrF excimer laser exposure will be described. FIG. 4 is a cross-sectional view showing the manufacturing process of the exposure mask according to the embodiment of the present invention.
【0025】図4(a)に示すように、石英等からなる
透明基板(透光性基板)401をスパッタ装置のチャン
バ内に導入し、SiにTiを12%ドープしたターゲッ
トを用いて、ArとN2 ガス中で反応性スパッタリング
法により、基板上401に膜厚が102.4nmのSi
Nx (TiN)z 膜402(位相シフト膜:x=0.8
8,z=0.12)を形成した。このとき、位相シフト
膜の透過率,位相差は、波長248nmで5.23%,
179.8度であった。As shown in FIG. 4A, a transparent substrate (translucent substrate) 401 made of quartz or the like is introduced into the chamber of the sputtering apparatus, and a target in which Si is doped with 12% of Ti is used. And a Si film having a thickness of 102.4 nm on the substrate 401 by the reactive sputtering method in N 2 gas.
Nx (TiN) z film 402 (phase shift film: x = 0.8
8, z = 0.12) was formed. At this time, the transmittance and phase difference of the phase shift film are 5.23% at a wavelength of 248 nm,
It was 179.8 degrees.
【0026】なお、本実施形態における位相シフト膜
は、第1の物質としてのSiNに第2の物質としてのT
iNを添加したものであるが、実質的にはSiNにTi
を添加したものである。また、成膜時のSiNx (Ti
N)z 膜402の屈折率,消衰係数,及び膜厚は露光時
の酸化反応等により所望の透過率,位相差になるよう
に、予め屈折率,消衰係数の変化量を見込んで設定し
た。The phase shift film according to the present embodiment uses SiN as the first substance and T as the second substance.
Although iN is added, it is essentially TiN to SiN.
Is added. In addition, SiNx (Ti
N) The z film 402 has a refractive index, an extinction coefficient, and a film thickness which are set in advance in consideration of the change amounts of the refractive index and the extinction coefficient so as to have desired transmittance and phase difference due to an oxidation reaction during exposure. did.
【0027】ここで、マスク完成後の実際の露光時の酸
化反応によりSiNx (TiN)zは、SiNx Oy T
iz (x=0.88,y=0.01,z=0.12)と
変化した。波長248nmでの照射前後における光学定
数の変化は以下のようになっていた。このとき、最終的
な透過率は6.09%、位相差は180度となってい
た。即ち、 照射前(SiNx (TiN)z ):2.21−0.53
2i 照射後(SiNx Oy Tiz ):2.21−0.504
i マスク作成工程は、図4(b)に示すように、位相シフ
ト膜であるSiNx (TiN)z 膜402上にEBレジ
スト403を塗布し、さらにEB描画時に生じるチャー
ジアップを防止するために、導電性の膜404をEBレ
ジスト403上に形成した。その後、図4(c)に示す
ように、EB描画により所望のレジストパターンを形成
した。Here, SiNx (TiN) z is converted to SiNx Oy T by the oxidation reaction during the actual exposure after the mask is completed.
It changed to iz (x = 0.88, y = 0.01, z = 0.12). The change in the optical constant before and after the irradiation at the wavelength of 248 nm was as follows. At this time, the final transmittance was 6.09% and the phase difference was 180 degrees. That is, before irradiation (SiNx (TiN) z): 2.21-0.53
After 2i irradiation (SiNx Oy Tiz): 2.21-0.504
In the i mask making process, as shown in FIG. 4B, an EB resist 403 is applied on the SiNx (TiN) z film 402 which is a phase shift film, and in order to prevent charge-up that occurs during EB writing, A conductive film 404 was formed on the EB resist 403. After that, as shown in FIG. 4C, a desired resist pattern was formed by EB drawing.
【0028】次いで、図4(d)に示すように、レジス
ト403のパターンをマスクとしてSiNx (TiN)
z 膜402を選択エッチングすることにより、SiNx
(TiN)z 膜402のパターニングを行った。このと
きのエッチングにはCDE(Chemical Dry Etching)や
RIE等を用いればよい。Then, as shown in FIG. 4D, SiNx (TiN) is used with the pattern of the resist 403 as a mask.
By selectively etching the z film 402, SiNx
The (TiN) z film 402 was patterned. For this etching, CDE (Chemical Dry Etching), RIE, or the like may be used.
【0029】その後、レジスト403のパターンを除去
することで、図4(e)に示すようなSiNx Tiz 半
透明位相シフトパターンを得た。このように本実施形態
によれば、露光光照射で生じる位相シフト膜の光学定数
変化を抑制し安定した光学性能を維持できるため、パタ
ーン転写精度の向上に寄与することができる。After that, the pattern of the resist 403 was removed to obtain a SiNx Tiz semitransparent phase shift pattern as shown in FIG. 4 (e). As described above, according to the present embodiment, since it is possible to suppress the change in the optical constant of the phase shift film caused by the irradiation of the exposure light and maintain the stable optical performance, it is possible to contribute to the improvement of the pattern transfer accuracy.
【0030】本実施形態の製造装置並びに製造方法によ
り得られた透過率6.09%、位相差180度のハーフ
トーン型位相シフトマスクを使用し、露光光源にKrF
エキシマレーザを用いて0.3μmのホールパターンの
転写結果を評価したところ、1.5μmの焦点深度を得
ることができた。また、同一マスクを500ロット照射
した時点で再度転写結果を評価したところ、焦点深度は
1.5μmとマスク作成時の性能をそのまま維持するこ
とでできた。A halftone phase shift mask having a transmittance of 6.09% and a phase difference of 180 degrees obtained by the manufacturing apparatus and the manufacturing method of this embodiment is used, and KrF is used as an exposure light source.
When the transfer result of the 0.3 μm hole pattern was evaluated using an excimer laser, a focal depth of 1.5 μm could be obtained. Further, when the transfer result was evaluated again when the same mask was irradiated for 500 lots, the depth of focus was 1.5 μm and it was possible to maintain the performance at the time of mask production as it was.
【0031】一方、TiをドープしないSiNx のみで
作成したマスクは500ロット照射後の0.3μmのホ
ールパターンの転写評価で焦点深度が0.8μmとマス
ク作成時の性能を大幅に劣化させていることが分った。On the other hand, the mask made of only SiNx not doped with Ti has a depth of focus of 0.8 μm in transfer evaluation of a hole pattern of 0.3 μm after irradiation of 500 lots, which significantly deteriorates the performance at the time of mask making. I found out.
【0032】なお、本発明は上述した実施形態に限定さ
れるものではない。実施形態では、位相シフト膜として
SiNx Oy Tiz 膜を用いたが、これに限らず他の薄
膜、例えばSi,Cr,Ge,Ti,Ta,Al,S
n,Hfなどの金属やAlSi,MoSi,WSi,N
iSi,AlCuSiなどの金属シリサイド膜、カーボ
ン、或いはこれらの酸化物,窒化物,炭化物,水素化
物,ハロゲン化物の単体又はこれらの混合物を用いても
同様の効果が得られる。The present invention is not limited to the above embodiment. In the embodiment, the SiNx Oy Tiz film is used as the phase shift film, but the present invention is not limited to this, and other thin films such as Si, Cr, Ge, Ti, Ta, Al and S are used.
Metals such as n and Hf, AlSi, MoSi, WSi, N
Similar effects can be obtained by using metal silicide films such as iSi and AlCuSi, carbon, or oxides, nitrides, carbides, hydrides or halides thereof or a mixture thereof.
【0033】また、他の露光光源、例えば水銀ランプの
i線やKrF,ArFエキシマレーザ光などを対象とし
た位相シフト膜に対しても適用可能である。また、膜形
成にはスパッタリング法を用いたが、これに限らずCV
D法、光励起CVD法、蒸着法、など他の成膜法によっ
て膜形成を行ってもよい。また、酸素濃度が膜内で勾配
を持つように成膜条件,改質条件を調整してもよい。Further, the present invention can be applied to other exposure light sources such as a phase shift film for an i-line of a mercury lamp or KrF or ArF excimer laser light. Further, although the sputtering method was used for the film formation, the present invention is not limited to this, and the
The film may be formed by another film forming method such as the D method, the photoexcited CVD method, or the vapor deposition method. Further, the film forming condition and the modifying condition may be adjusted so that the oxygen concentration has a gradient in the film.
【0034】また、本実施形態は酸化に伴う位相シフト
膜の光学定数変化を相殺するように調整したが、これに
限らず他の反応による光学定数変化を相殺するように添
加する材料を選択してもよい。また、位相シフト膜の膜
厚を本発明の要旨を逸脱しない範囲において適当な厚さ
にしてもよい。また、導電性膜を位相シフト膜上に形成
する代わりに、基板に予め帯電防止の役割を果たす膜が
形成されたものを用いてもよい。Further, although the present embodiment is adjusted so as to cancel the change in the optical constant of the phase shift film due to the oxidation, the material to be added is selected so as to cancel the change in the optical constant due to other reactions. May be. Further, the film thickness of the phase shift film may be set to an appropriate thickness without departing from the scope of the present invention. Further, instead of forming the conductive film on the phase shift film, a substrate on which a film that plays a role of antistatic is formed in advance may be used.
【0035】また、本発明は透明基板上に位相シフト膜
を形成した位相シフトマスクに限らず、これ以外に遮光
膜を形成したレベンソン型にも適用できる。その他、本
発明の要旨を逸脱しない範囲で、種々変形して実施する
ことができる。The present invention is not limited to the phase shift mask in which the phase shift film is formed on the transparent substrate, but can be applied to a Levenson type in which a light shielding film is formed in addition to this. In addition, various modifications can be made without departing from the scope of the present invention.
【0036】[0036]
【発明の効果】以上詳述したように本発明によれば、位
相シフト膜中に露光時に生じる酸化反応等による光学定
数変化を相殺するように適当な元素を添加することで、
露光光照射に対する位相シフト膜の透過率,位相差の変
動を抑制することが可能となった。これにより、マスク
作成が容易になると共に、マスク特性変化を抑えること
ができた。As described above in detail, according to the present invention, by adding an appropriate element in the phase shift film so as to offset the change in optical constant due to the oxidation reaction or the like that occurs during exposure,
It has become possible to suppress variations in the transmittance and phase difference of the phase shift film due to exposure light irradiation. As a result, it was possible to easily make a mask and suppress changes in mask characteristics.
【図1】露光前後おける第1,第2の化合物の光学定数
変化を示す図。FIG. 1 is a diagram showing changes in optical constants of first and second compounds before and after exposure.
【図2】露光前後での透過率,位相差変化を相殺するよ
うな光学定数変化の組み合わせを示す図。FIG. 2 is a diagram showing a combination of changes in optical constants that cancel changes in transmittance and phase difference before and after exposure.
【図3】波長248nmでのSiNx とTiの酸化によ
る光学定数変化を示す図。FIG. 3 is a diagram showing changes in optical constants due to oxidation of SiNx and Ti at a wavelength of 248 nm.
【図4】第1の実施形態に係わる露光用マスクの製造工
程を示す図。FIG. 4 is a view showing a manufacturing process of the exposure mask according to the first embodiment.
401…石英製透明基板(透光性基板) 402…Ti添加のSiN膜(位相シフト膜) 403…EBレジスト 404…導電膜 401 ... Quartz transparent substrate (translucent substrate) 402 ... Ti-added SiN film (phase shift film) 403 ... EB resist 404 ... Conductive film
Claims (4)
らなるパターンを有する露光用マスクにおいて、 前記位相シフト膜は、露光光照射によって光学定数に変
化が生じる第1の物質に、前記露光光照射によって第1
の物質とは異なる光学定数変化が生じる第2の物質を添
加又は混合して形成されてなることを特徴とする露光用
マスク。1. An exposure mask having a pattern composed of at least a phase shift film on a light-transmissive substrate, wherein the phase shift film is a first substance whose optical constant is changed by irradiation of exposure light. First by irradiation
An exposure mask formed by adding or mixing a second substance that causes a change in optical constant different from that of the above substance.
の変化は、前記露光光照射による屈折率,消衰係数に関
する増減が相反する方向であることを特徴とする請求項
1記載の露光用マスク。2. The change in the optical constants of the first substance and the second substance is such that the increase and decrease in the refractive index and the extinction coefficient due to the irradiation of the exposure light are in opposite directions. Exposure mask.
の変化は、光重合,光酸化又は光分解により引き起こさ
れるものであることを特徴とする請求項1記載の露光用
マスク。3. The exposure mask according to claim 1, wherein the change of the optical constants of the first substance and the second substance is caused by photopolymerization, photooxidation or photolysis.
あり、第2の物質はTiであることを特徴とする請求項
1又は2記載の露光用マスク。4. The exposure mask according to claim 1, wherein the first substance is SiNx or SiNxOy and the second substance is Ti.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP162696A JPH09189990A (en) | 1996-01-09 | 1996-01-09 | Mask for exposure |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP162696A JPH09189990A (en) | 1996-01-09 | 1996-01-09 | Mask for exposure |
Publications (1)
Publication Number | Publication Date |
---|---|
JPH09189990A true JPH09189990A (en) | 1997-07-22 |
Family
ID=11506755
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP162696A Pending JPH09189990A (en) | 1996-01-09 | 1996-01-09 | Mask for exposure |
Country Status (1)
Country | Link |
---|---|
JP (1) | JPH09189990A (en) |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2005292164A (en) * | 2004-03-31 | 2005-10-20 | Toppan Printing Co Ltd | Halftone phase shift mask blank, halftone phase shift mask and pattern transfer method |
-
1996
- 1996-01-09 JP JP162696A patent/JPH09189990A/en active Pending
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2005292164A (en) * | 2004-03-31 | 2005-10-20 | Toppan Printing Co Ltd | Halftone phase shift mask blank, halftone phase shift mask and pattern transfer method |
JP4535241B2 (en) * | 2004-03-31 | 2010-09-01 | 凸版印刷株式会社 | Halftone phase shift mask blank, halftone phase shift mask, and pattern transfer method |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
JP3286103B2 (en) | Method and apparatus for manufacturing exposure mask | |
US9436079B2 (en) | Phase shift mask blank, method of manufacturing the same, and phase shift mask | |
US6087047A (en) | Phase shift mask and phase shift mask blank | |
JP3253783B2 (en) | Halftone phase shift mask and method of manufacturing the same | |
US20090057143A1 (en) | Film-depositing target and preparation of phase shift mask blank | |
TW200537240A (en) | Halftone phase shift mask blank, halftone phase shift mask and their preparation | |
US6503668B2 (en) | Phase shift mask blank, phase shift mask, and method of manufacture | |
EP1116999B1 (en) | Phase shift mask blank, phase shift mask and method of manufacture | |
JP3339716B2 (en) | Manufacturing method of exposure mask | |
JP3472528B2 (en) | Phase shift mask and phase shift mask blank | |
JP3696320B2 (en) | Phase shift mask, phase shift mask blank, and manufacturing method thereof | |
TW544549B (en) | Half-tone type phase shift mask blank, process for prodncing half-tone type phase shift mask, pattern transfer method, laminate and method of forming pattern | |
JP2996613B2 (en) | Phase shift mask blank and method of manufacturing phase shift mask | |
JP2002062638A (en) | Mask blank, photomask, pattern forming method and method for producing semiconductor device | |
JP2005062894A (en) | Phase shift mask blank and phase shift mask | |
US6514642B2 (en) | Phase shift mask and method of manufacture | |
JPH09189990A (en) | Mask for exposure | |
JP2002040625A (en) | Mask for exposure, resist pattern forming method and method for producing substrate for the mask | |
JP2002189283A (en) | Phase shift mask blank, phase shift mask and method for producing phase shift mask | |
JP2002189284A (en) | Phase shift mask blank, phase shift mask and method for producing these | |
JPH0675359A (en) | Mask for exposure and its production | |
JPH08272074A (en) | Halftone phase shift photomask and blank for halftone phase shift photomask | |
JPH04125643A (en) | Photomask and photomask blank | |
JP3951704B2 (en) | Halftone phase shift mask, blank thereof, and manufacturing method thereof | |
JPH07248609A (en) | Phase shift mask blank and phase shift mask |