JPH0234453B2 - - Google Patents
Info
- Publication number
- JPH0234453B2 JPH0234453B2 JP57028765A JP2876582A JPH0234453B2 JP H0234453 B2 JPH0234453 B2 JP H0234453B2 JP 57028765 A JP57028765 A JP 57028765A JP 2876582 A JP2876582 A JP 2876582A JP H0234453 B2 JPH0234453 B2 JP H0234453B2
- Authority
- JP
- Japan
- Prior art keywords
- resist
- layer
- pattern
- resist layer
- etching
- 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.)
- Expired - Lifetime
Links
- 238000000034 method Methods 0.000 claims description 50
- 239000007789 gas Substances 0.000 claims description 30
- 239000000463 material Substances 0.000 claims description 25
- 239000000758 substrate Substances 0.000 claims description 24
- 239000011368 organic material Substances 0.000 claims description 12
- 238000001312 dry etching Methods 0.000 claims description 8
- MYMOFIZGZYHOMD-UHFFFAOYSA-N Dioxygen Chemical compound O=O MYMOFIZGZYHOMD-UHFFFAOYSA-N 0.000 claims description 7
- 229920000193 polymethacrylate Polymers 0.000 claims description 7
- 230000005855 radiation Effects 0.000 claims description 7
- 229910001882 dioxygen Inorganic materials 0.000 claims description 6
- 125000001997 phenyl group Chemical group [H]C1=C([H])C([H])=C(*)C([H])=C1[H] 0.000 claims description 6
- 238000000059 patterning Methods 0.000 claims description 5
- 239000010410 layer Substances 0.000 description 93
- 238000005530 etching Methods 0.000 description 35
- 239000010408 film Substances 0.000 description 35
- 229920003229 poly(methyl methacrylate) Polymers 0.000 description 21
- 239000004926 polymethyl methacrylate Substances 0.000 description 21
- 230000018109 developmental process Effects 0.000 description 9
- 239000011248 coating agent Substances 0.000 description 8
- 238000000576 coating method Methods 0.000 description 8
- 238000007796 conventional method Methods 0.000 description 6
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 5
- 238000010586 diagram Methods 0.000 description 5
- 238000010894 electron beam technology Methods 0.000 description 5
- 229910052736 halogen Inorganic materials 0.000 description 5
- 150000002367 halogens Chemical class 0.000 description 5
- 229910052760 oxygen Inorganic materials 0.000 description 5
- 239000001301 oxygen Substances 0.000 description 5
- VZGDMQKNWNREIO-UHFFFAOYSA-N tetrachloromethane Chemical compound ClC(Cl)(Cl)Cl VZGDMQKNWNREIO-UHFFFAOYSA-N 0.000 description 4
- 230000007423 decrease Effects 0.000 description 3
- 230000003247 decreasing effect Effects 0.000 description 3
- 150000002430 hydrocarbons Chemical class 0.000 description 3
- 229910052710 silicon Inorganic materials 0.000 description 3
- 239000002904 solvent Substances 0.000 description 3
- 239000010409 thin film Substances 0.000 description 3
- VGGSQFUCUMXWEO-UHFFFAOYSA-N Ethene Chemical compound C=C VGGSQFUCUMXWEO-UHFFFAOYSA-N 0.000 description 2
- 239000005977 Ethylene Substances 0.000 description 2
- CERQOIWHTDAKMF-UHFFFAOYSA-M Methacrylate Chemical compound CC(=C)C([O-])=O CERQOIWHTDAKMF-UHFFFAOYSA-M 0.000 description 2
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 238000002156 mixing Methods 0.000 description 2
- 230000007261 regionalization Effects 0.000 description 2
- 239000010703 silicon Substances 0.000 description 2
- 239000004215 Carbon black (E152) Substances 0.000 description 1
- 239000004793 Polystyrene Substances 0.000 description 1
- 239000000654 additive Substances 0.000 description 1
- 230000000996 additive effect Effects 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 238000001514 detection method Methods 0.000 description 1
- NBVXSUQYWXRMNV-UHFFFAOYSA-N fluoromethane Chemical compound FC NBVXSUQYWXRMNV-UHFFFAOYSA-N 0.000 description 1
- 229930195733 hydrocarbon Natural products 0.000 description 1
- 239000007788 liquid Substances 0.000 description 1
- 239000012528 membrane Substances 0.000 description 1
- 229920002120 photoresistant polymer Polymers 0.000 description 1
- 238000001020 plasma etching Methods 0.000 description 1
- 238000006116 polymerization reaction Methods 0.000 description 1
- 229920002223 polystyrene Polymers 0.000 description 1
- 238000002360 preparation method Methods 0.000 description 1
- 230000001105 regulatory effect Effects 0.000 description 1
- 239000002356 single layer Substances 0.000 description 1
- 230000008961 swelling Effects 0.000 description 1
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L21/00—Processes or apparatus adapted for the manufacture or treatment of semiconductor or solid state devices or of parts thereof
- H01L21/02—Manufacture or treatment of semiconductor devices or of parts thereof
- H01L21/04—Manufacture or treatment of semiconductor devices or of parts thereof the devices having potential barriers, e.g. a PN junction, depletion layer or carrier concentration layer
- H01L21/18—Manufacture or treatment of semiconductor devices or of parts thereof the devices having potential barriers, e.g. a PN junction, depletion layer or carrier concentration layer the devices having semiconductor bodies comprising elements of Group IV of the Periodic Table or AIIIBV compounds with or without impurities, e.g. doping materials
- H01L21/30—Treatment of semiconductor bodies using processes or apparatus not provided for in groups H01L21/20 - H01L21/26
- H01L21/31—Treatment of semiconductor bodies using processes or apparatus not provided for in groups H01L21/20 - H01L21/26 to form insulating layers thereon, e.g. for masking or by using photolithographic techniques; After treatment of these layers; Selection of materials for these layers
- H01L21/3105—After-treatment
- H01L21/311—Etching the insulating layers by chemical or physical means
- H01L21/31127—Etching organic layers
- H01L21/31133—Etching organic layers by chemical means
- H01L21/31138—Etching organic layers by chemical means by dry-etching
Landscapes
- Engineering & Computer Science (AREA)
- Chemical & Material Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- General Chemical & Material Sciences (AREA)
- Physics & Mathematics (AREA)
- Condensed Matter Physics & Semiconductors (AREA)
- General Physics & Mathematics (AREA)
- Manufacturing & Machinery (AREA)
- Computer Hardware Design (AREA)
- Microelectronics & Electronic Packaging (AREA)
- Power Engineering (AREA)
- Drying Of Semiconductors (AREA)
Description
【発明の詳細な説明】
本発明は、ドライエツチングを利用して基板表
面に微細なパターンを高精度に形成する方法に関
する。DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method of forming fine patterns on the surface of a substrate with high precision using dry etching.
従来の方法では基板表面にただ一種類のレジス
ト膜を塗布し、塗布膜厚などの塗膜条件に応じた
最適な露光・現像条件を選んで露光・現像を行う
ことにより所定のパターンを形成していたが、凹
凸を有する基板上では場所により塗布膜厚が変化
したり塗膜表面に凹凸が生じたりするため、露
光・現像の最適条件が場合により異なつてしまい
微細パターンを基板表面全面にわたつて均一に高
精度に形成するのが困難であるという欠点があつ
た。この場合、レジスト膜厚を凹凸段差に比べ相
当厚めにすれば場所による膜厚変動率や塗膜表面
の凹凸はある程度緩和されるが、レジスト膜が厚
いほど現像処理での膨潤などのためパターン解像
性が悪化するので微細なパターンの形成には適さ
ない。 In the conventional method, only one type of resist film is applied to the surface of the substrate, and a predetermined pattern is formed by performing exposure and development by selecting the optimal exposure and development conditions according to the coating film conditions such as the coating film thickness. However, on a substrate with unevenness, the coating film thickness changes depending on the location and the coating surface becomes uneven, so the optimal conditions for exposure and development differ depending on the case, making it difficult to apply a fine pattern to the entire surface of the substrate. However, it has the disadvantage that it is difficult to form it uniformly and with high precision. In this case, if the resist film thickness is made considerably thicker than the uneven steps, the variation rate of the film thickness depending on the location and the unevenness of the coating film surface will be alleviated to some extent, but the thicker the resist film, the more the pattern will be resolved due to swelling during the development process. Since the image quality deteriorates, it is not suitable for forming fine patterns.
以上のような欠点を除くための方法として、２
層レジストパターン形成方法が知られている（例
えば米国特許第4244799号明細書参照）。その方法
を添付図面に基づいて説明する。第１図ａ〜ｄ
は、この従来の２層レジストパターン形成方法の
工程図である。第１図に示した工程(a)において、
基板１上に第１レジスト層２を、その表面が基板
表面の凹凸にかかわらず平坦となるように、凹凸
段差に比し充分厚く形成し、更にその上に第２レ
ジスト層３を均一な厚さに形成する。ここでは、
第２レジスト層３としてポジレジストを用いた場
合について例示する。この後工程(b)において、紫
外線又は電子線等の放射線４で選択的に露光し、
第２レジスト層３中に感光領域５を形成する。続
いて工程(c)において、この感光領域５を選択的に
除去し、所要の第１のマスクパターン６を形成す
る。更に工程(d)において第１のマスクパターン６
をマスクに第１レジスト層２を選択的に除去して
所要の第２のマスクパターン７を形成する。ここ
で第１レジスト層２の選択的除去は液体溶媒によ
る湿式処理でも行いうるが、微細パターンを精度
よく形成するためにはドライエツチング処理によ
らなけらばならない。従来の方法では純酸素ガス
を用いたプラズマアツシヤー処理などで第１レジ
スト層２を選択除去していたが、この場合には第
１レジスト層材料と第２レジスト層材料とのエツ
チング選択性が高高２〜３倍と小さいので、マス
クとして用いる第２レジスト層３の厚みは第１レ
ジスト層２の最大厚さの1/2〜1/3と充分厚くする
必要があつた。このため第２レジスト層の露光に
おいて微細パターンの解像が困難になるという欠
点があつた。なお第１図においては第２レジスト
層３としてポジレジストの場合を示したが、これ
がネガレジストの場合も従来法の欠点は本質的に
変りがない。 As a method to eliminate the above drawbacks, 2.
Layered resist patterning methods are known (see, eg, US Pat. No. 4,244,799). The method will be explained based on the accompanying drawings. Figure 1 a-d
These are process diagrams of this conventional two-layer resist pattern forming method. In step (a) shown in Figure 1,
A first resist layer 2 is formed on the substrate 1 to be sufficiently thick compared to the uneven steps so that the surface thereof is flat regardless of the unevenness of the substrate surface, and a second resist layer 3 is formed on top of the first resist layer 3 to have a uniform thickness. to form. here,
A case where a positive resist is used as the second resist layer 3 will be illustrated. In the subsequent step (b), selectively exposing to radiation 4 such as ultraviolet rays or electron beams,
A photosensitive area 5 is formed in the second resist layer 3. Subsequently, in step (c), this photosensitive region 5 is selectively removed to form a required first mask pattern 6. Furthermore, in step (d), the first mask pattern 6
Using the mask as a mask, the first resist layer 2 is selectively removed to form a desired second mask pattern 7. Here, selective removal of the first resist layer 2 can be performed by wet processing using a liquid solvent, but in order to form a fine pattern with high precision, dry etching processing must be used. In the conventional method, the first resist layer 2 was selectively removed by plasma assher treatment using pure oxygen gas, but in this case, the etching selectivity between the first resist layer material and the second resist layer material was Since the height is as small as 2 to 3 times, the thickness of the second resist layer 3 used as a mask needs to be sufficiently thick to 1/2 to 1/3 of the maximum thickness of the first resist layer 2. For this reason, there was a drawback that it became difficult to resolve fine patterns during exposure of the second resist layer. Although FIG. 1 shows the case where a positive resist is used as the second resist layer 3, the drawbacks of the conventional method are essentially the same even when this is a negative resist.
本発明の目的は、従来法におけるこのような欠
点を除去するために、相異なるレジスト材料間の
エツチング選択性の大きなドライエツチング方法
を提供することである。 SUMMARY OF THE INVENTION It is an object of the present invention to provide a dry etching method with high etching selectivity between different resist materials in order to eliminate these drawbacks of conventional methods.
すなわち本発明を概説すれば、本発明は、所定
の基板表面上に、ポリメタクリレートを主鎖構造
とする有機材料層、更にその上にベンゼン環構造
を含有する有機レジスト材料層を有するパターン
形成材料に対して、該有機レジスト材料層に対す
る放射線による選択的露光処理、及びそれに続く
現像処理を含む処理により、該有機レジスト材料
層をパターン化して所要のマスクパターンを形成
する工程と、該マスクパターンをマスクとしてド
ライエツチング処理により該有機材料層をパター
ン化する工程を含むパターン形成方法において、
該ドライエツチング処理を、酸素ガスと、CCl4
ガスとを含有する混合ガスから生じさせた低温ガ
スプラズマを用いて行うことを特徴とするパター
ン形成方法に関する。 That is, to summarize the present invention, the present invention provides a pattern forming material having, on the surface of a predetermined substrate, an organic material layer having a main chain structure of polymethacrylate, and further an organic resist material layer containing a benzene ring structure thereon. a step of patterning the organic resist material layer to form a desired mask pattern by a process including selectively exposing the organic resist material layer to radiation and a subsequent development process; A pattern forming method including a step of patterning the organic material layer by dry etching as a mask,
The dry etching process is carried out using oxygen gas and CCl 4
The present invention relates to a pattern forming method characterized in that it is carried out using a low-temperature gas plasma generated from a mixed gas containing a gas.
本発明方法により、酸素ガスと、CCl4ガスと
を含有する混合ガスを低温ガスプラズマ化してド
ライエツチング処理に用いると、レジスト材料間
の選択性は極めて高くできるから、工程の単純な
２層レジストパターン形成法に本発明の方法を用
いれば、露光パターンを形成する第２レジスト層
の厚さを充分薄くすることができ、微細パターン
の形成に有利である。また本発明の方法によれば
全レジスト膜厚を大きくしても微細レジストパタ
ーンの形成には支障が無いから、下地基板表面材
料の加工をドライエツチングにより行う工程にお
いてレジスト層に対する下地被加工層のエツチン
グ選択性が余り大きくない場合でも全レジスト膜
厚を充分大きくすることにより下地被加工層のエ
ツチングを問題無く行える。また、下地層加工後
のレジスト除去も酸素アツシヤー法などの従来法
で行えるので、工程の複雑化は避けられる。更に
本発明方法の他の応用分野として、種種のパター
ン形成に用いられるリフトオフ法のためのレジス
トパターンに適用することもできる。本発明方法
によれば、アスペクト比の極めて大きなレジスト
パターンが容易に形成できるから、このレジスト
パターン形成後に所要の膜を周知の種種の成膜方
法により堆積すると、レジストパターン段差によ
り堆積膜が上下に分離される。しかる後に、レジ
ストパターンと共にその表面上に堆積した膜を除
去すれば、堆積膜のうち基板に付着した部分のみ
が残り、所要の膜材料からなる所要のパターンが
形成される。更に第１レジスト層のエツチングの
際にエツチング装置、条件を適宜選択して、例え
ば、等方的エツチングを行えば、第１レジスト層
が第２レジスト層パターンに対してアンダーカツ
トされるので、堆積膜の上下の分離がより確実に
成され、リフトオフが容易になると共に歩留りの
向上に寄与する。 According to the method of the present invention, when a mixed gas containing oxygen gas and CCl 4 gas is turned into low-temperature gas plasma and used for dry etching processing, the selectivity between resist materials can be extremely high. If the method of the present invention is used for pattern formation, the thickness of the second resist layer forming the exposure pattern can be made sufficiently thin, which is advantageous for forming fine patterns. Furthermore, according to the method of the present invention, even if the total resist film thickness is increased, there is no problem in forming a fine resist pattern. Even if the etching selectivity is not very high, by making the total resist film thickness sufficiently large, the underlying layer to be processed can be etched without problems. Furthermore, since the resist can be removed after the underlayer processing by a conventional method such as an oxygen assher method, complication of the process can be avoided. Furthermore, as another field of application of the method of the present invention, it can also be applied to resist patterns for lift-off methods used for forming various types of patterns. According to the method of the present invention, a resist pattern with an extremely large aspect ratio can be easily formed. Therefore, when a desired film is deposited by various well-known film forming methods after forming this resist pattern, the deposited film will be vertically stacked due to the step difference in the resist pattern. separated. Thereafter, when the film deposited on the surface of the resist pattern is removed, only the portion of the deposited film that has adhered to the substrate remains, and a desired pattern made of the desired film material is formed. Furthermore, when etching the first resist layer, if the etching equipment and conditions are appropriately selected and, for example, isotropic etching is performed, the first resist layer will be undercut with respect to the second resist layer pattern. The upper and lower parts of the membrane can be separated more reliably, making lift-off easier and contributing to improved yield.
本発明方法において、第１レジスト層に使用す
るポリメタクリレートを主鎖構造とする有機材料
層の代表例としては、ポリメチルメタクリレート
（PMMA）、ポリテトラフルオロプロピルメタク
リレート（FPM）が挙げられ、他方、第２レジ
スト層に使用するベンゼン環構造を含有する有機
レジスト材料の代表例としては、AZ−1350〔シプ
レー（Shipley）社製〕、クロロメチル化ポリスチ
レン（CMS）が挙げられる。 In the method of the present invention, typical examples of the organic material layer having a main chain structure of polymethacrylate used in the first resist layer include polymethyl methacrylate (PMMA) and polytetrafluoropropyl methacrylate (FPM); Representative examples of the organic resist material containing a benzene ring structure used in the second resist layer include AZ-1350 (manufactured by Shipley) and chloromethylated polystyrene (CMS).
次に本発明方法を添付図面に基づいて具体的に
説明する。 Next, the method of the present invention will be specifically explained based on the accompanying drawings.
第２図は、本発明方法で使用するエツチング装
置の一例の概要図である。第２図において、８は
真空容器、９はガス導入管、１２は高周波電源、
１３は試料基板、１５は排気管、１６は可変コン
ダクタンスバルブ、１７は平行平板型上部電極、
１８は平行平板型下部電極、１９はプラズマ、２
０はO2用マスフローメーター、２１はCCl4用マ
スフローメーターである。第３図は、第２図に示
した装置を用いて得られた、O2＋CCl4混合ガス
中のCCl4濃度（％）（横軸）と各種レジストのエ
ツチレート（Å／分）（縦軸）との関係を示すグ
ラフである。 FIG. 2 is a schematic diagram of an example of an etching apparatus used in the method of the present invention. In Fig. 2, 8 is a vacuum container, 9 is a gas introduction tube, 12 is a high frequency power source,
13 is a sample substrate, 15 is an exhaust pipe, 16 is a variable conductance valve, 17 is a parallel plate type upper electrode,
18 is a parallel plate type lower electrode, 19 is a plasma, 2
0 is a mass flow meter for O2 , and 21 is a mass flow meter for CCl4 . Figure 3 shows the CCl 4 concentration (%) in the O 2 + CCl 4 mixed gas (horizontal axis) and the etching rate (Å/min) of various resists (vertical axis) obtained using the apparatus shown in Figure 2. ) is a graph showing the relationship between
以下、本発明方法を実施例により更に具体的に
説明するが、本発明はこれらに限定されるもので
はない。 Hereinafter, the method of the present invention will be explained in more detail with reference to Examples, but the present invention is not limited thereto.
実施例 １
第２図に示した装置及びO2＋CCl4混合ガスを
使用した。真空容器８中に、平行平板型の上下電
極１７，１８を設け、外部電源１２により
13.56MHzの高周波電力50Wを下部電極１８に印
加して、両電極間にプラズマ１９を発生させた。
ガスはO2及びCCl4それぞれの流量をマスフロー
メーター２０と２１により調節し所要の混合比と
したのち、ガス導入管９より真空容器８内に流入
させた。圧力は排気管１５に接続して設けられた
可変コンダクタンスバルブ１６により調節し、
0.03トル一定とした。試料１３は下部電極１８の
中央部に水平に載置した。なお、下部電極温度は
図示していない温度調節系により50℃一定に保つ
た。第３図は試料基板に塗布した各種レジスト膜
はCCl4濃度を変えてエツチングしたときのそれ
ぞれのレジストのエツチレートの実測値のグラフ
である。AZ−1350とCMS両者のエツチレートは
CCl4濃度50％以上で急激に低下し、67％以上で
は全くエツチングが検出できなかつた。一方、
PMMA、FPMでは両者ともCCl4濃度の増大と共
にエツチレートが増加し、CCl4濃度67％付近で
最大値を示したのち100％では最大値の約1/2のエ
ツチレートに低下した。CMSに対するPMMAの
エツチレート比を例にとると、CCl450％で約５
であるのが60％以上では無限大となる。このよう
にCCl4を適量混合することによりレジスト材料
間のエツチング選択性を著しく高くすることがで
きた。Example 1 The apparatus shown in FIG. 2 and an O 2 +CCl 4 mixed gas were used. Parallel plate type upper and lower electrodes 17 and 18 are provided in the vacuum container 8, and are powered by an external power source 12.
A high frequency power of 50 W at 13.56 MHz was applied to the lower electrode 18 to generate plasma 19 between both electrodes.
The flow rates of O 2 and CCl 4 were adjusted using mass flow meters 20 and 21 to obtain a desired mixing ratio, and then the gases were introduced into the vacuum container 8 through the gas introduction pipe 9. The pressure is regulated by a variable conductance valve 16 connected to the exhaust pipe 15,
It was assumed to be constant at 0.03 Torr. The sample 13 was placed horizontally at the center of the lower electrode 18. Note that the lower electrode temperature was kept constant at 50° C. by a temperature control system (not shown). FIG. 3 is a graph of the measured values of the etching rate of each resist film when the various resist films coated on the sample substrate were etched with varying CCl 4 concentrations. The etching rate of both AZ-1350 and CMS is
At a CCl 4 concentration of 50% or higher, it decreased rapidly, and at a CCl 4 concentration of 67% or higher, no etching could be detected. on the other hand,
For both PMMA and FPM, the etching rate increased as the CCl 4 concentration increased, reaching a maximum value at around 67% CCl 4 concentration, and then decreasing to about 1/2 of the maximum value at 100%. For example, the etching rate ratio of PMMA to CMS is approximately 5 at 50% CCl4 .
However, if it exceeds 60%, it becomes infinite. By mixing an appropriate amount of CCl 4 in this way, it was possible to significantly increase the etching selectivity between resist materials.
次に本発明による２層レジストパターン形成の
実施例を述べる。 Next, an example of forming a two-layer resist pattern according to the present invention will be described.
実施例 ２
シリコンウエハ上に第１レジスト層として
PMMAを約5000Åの厚さに塗布し、更にその上
に第２レジスト層としてAZ−1350を約3000Åの
厚さに塗布し、所定のベーキングを行つて２層レ
ジスト層を形成した。AZ−1350レジスト層を紫
外線密着露光法により露光し最小線幅1.5μｍのパ
ターンを形成した。現像は所定の液により湿式法
で行つた。この後、第２図に示した装置を用い酸
素流量10sccm、CCl4流量20sccm、圧力0.03トル、
高周波印加電力50Wの条件で約８分エツチングを
行い第１レジスト層のPMMA層をエツチングし
た。このとき、AZ−1350層は全くエツチングさ
れずに残り総膜厚8000Åの良好なパターンが得ら
れた。Example 2 As a first resist layer on a silicon wafer
PMMA was coated to a thickness of about 5000 Å, and AZ-1350 was further coated thereon to a thickness of about 3000 Å as a second resist layer, followed by predetermined baking to form a two-layer resist layer. The AZ-1350 resist layer was exposed to ultraviolet contact exposure to form a pattern with a minimum line width of 1.5 μm. Development was carried out by a wet method using a predetermined solution. After this, using the apparatus shown in Figure 2, the oxygen flow rate was 10 sccm, the CCl 4 flow rate was 20 sccm, the pressure was 0.03 torr,
Etching was performed for about 8 minutes under the condition of high frequency applied power of 50 W to etch the PMMA layer of the first resist layer. At this time, the AZ-1350 layer was not etched at all, and a good pattern with a total film thickness of 8000 Å was obtained.
実施例 ３
第１レジスト層としてPMMA（塗布膜厚5000
Å）、第２レジスト層としてCMS（塗布膜厚2500
Å）を用いた。CMS層には電子ビーム露光法及
び湿式現像法を使用して最小線幅0.5μｍの微細パ
ターンを形成した。PMMA層のエツチングはや
はり第２図の装置を用い酸素流量8sccm、CCl4流
量22sccm、圧力0.03トル、高周波電力50Wの条
件で８分30秒行つた。CMS層の膜厚は全く減少
せず、高いアスペクト比の微細パターンを得るこ
とができた。Example 3 PMMA (coating film thickness: 5000 mm) was used as the first resist layer.
Å), CMS as the second resist layer (coating film thickness 2500
Å) was used. A fine pattern with a minimum line width of 0.5 μm was formed on the CMS layer using an electron beam exposure method and a wet development method. The PMMA layer was etched using the apparatus shown in FIG. 2 for 8 minutes and 30 seconds under conditions of an oxygen flow rate of 8 sccm, a CCl 4 flow rate of 22 sccm, a pressure of 0.03 Torr, and a high frequency power of 50 W. The thickness of the CMS layer did not decrease at all, and a fine pattern with a high aspect ratio could be obtained.
基板表面に凹凸がある場合には第１レジスト層
の表面を平坦に塗布するとその塗布膜厚は第１図
のように場所ごとに異なる。したがつて第１レジ
スト層のエツチングに要する時間も場所ごとに異
なり、最大膜厚部を除去し終るまでエツチングす
ると、オーバーエツチングとなる場所が生じる。
本発明の方法ではハロゲン系の活性種がエツチン
グガス中に含まれているため基板表面がハロゲン
系活性種によりエツチングされやすい材料、例え
ば、Al、Mo、Siなどで覆われている場合には２
層レジストパターンのオーバーエツチング時間中
にこれら基板表面材料がエツチングされることに
なる。このことは２層レジストパターン形成に引
続いて行われる、基板表面材料のエツチング処理
において、エツチングパターン形状、寸法の不均
一を生む原因ともなり得る。そこでこのような基
板表面材料の場合には、２層レジストパターン形
成時のエツチング処理を２段階に分けて行うこと
も可能である。第１段階はハロゲンを含む混合ガ
スプラズマにより第１レジスト層の最小膜厚部を
完全にエツチング除去する時間まで行い、続いて
第２段階ではガスをハロゲンを含まないガス、例
えば純酸素や、酸素とエチレン等の炭化水素ガス
との混合ガスに切替えてエツチングを行えば、基
板表面材料を損うことなく、また第２レジスト層
のエツチングによる膜厚減少分を最小限に留める
ことができる。この方法による実施例を次に示
す。 If the surface of the substrate is uneven, if the first resist layer is applied evenly on the surface, the thickness of the applied film will vary from place to place as shown in FIG. Therefore, the time required for etching the first resist layer varies depending on the location, and if etching is performed until the maximum thickness portion is removed, overetching occurs in some locations.
In the method of the present invention, halogen-based active species are contained in the etching gas, so if the substrate surface is covered with a material that is easily etched by halogen-based active species, such as Al, Mo, Si, etc.
These substrate surface materials will be etched during the overetching of the layer resist pattern. This may cause non-uniformity in the shape and size of the etching pattern in the etching process of the substrate surface material that is performed subsequent to the formation of the two-layer resist pattern. Therefore, in the case of such a substrate surface material, it is also possible to perform the etching process in two stages when forming a two-layer resist pattern. The first step is to use a halogen-containing mixed gas plasma until the minimum thickness of the first resist layer is completely etched away, and the second step is to use a halogen-free gas such as pure oxygen or oxygen. If etching is performed by switching to a mixed gas of ethylene and a hydrocarbon gas such as ethylene, the substrate surface material will not be damaged, and the reduction in film thickness of the second resist layer due to etching can be kept to a minimum. Examples using this method are shown below.
実施例 ４
約5000Åの高低差の差を有するシリコンウエハ
上に第１レジスト層としてPMMAを塗布膜表面
が平滑となるように約1μの厚さに塗布したのち、
CMSレジストを第２レジスト層として約3000Å
重ねて塗布した。CMS層に電子ビーム法でパタ
ーンを形成した後、実施例３と同じくO2＋CCl4
（73％）PMMA層をエツチングした。ウエハ表面
段差の段上部にPMMAが約500Å残る時間でエツ
チングを停止し、ガスをO2＋C2H4（50％）に切替
えた。このガスで同一の放電条件によりエツチン
グを再開し約30分PMMA層をエツチングした。
この結果、段下部のPMMA層も含めて完全に除
去を終了した。この処理によるCMS層の膜厚減
少は約750Åと小さかつた。また基板Si表面は全
くエツチングされず上記の効果が確められた。Example 4 PMMA was coated as a first resist layer on a silicon wafer having a height difference of about 5000 Å to a thickness of about 1 μ so that the surface of the coating film was smooth.
Approximately 3000Å with CMS resist as second resist layer
It was applied in layers. After forming a pattern on the CMS layer by electron beam method, O 2 + CCl 4 as in Example 3.
(73%) Etched PMMA layer. Etching was stopped when about 500 Å of PMMA remained on the top of the wafer surface step, and the gas was switched to O 2 +C 2 H 4 (50%). Etching was restarted using this gas under the same discharge conditions, and the PMMA layer was etched for about 30 minutes.
As a result, complete removal was completed, including the PMMA layer at the bottom of the step. The decrease in the thickness of the CMS layer due to this treatment was as small as approximately 750 Å. Furthermore, the Si surface of the substrate was not etched at all, confirming the above effect.
また本発明の趣旨に従えば、第１レジスト層を
２種以上の有機材料薄膜から成る積層構造とし、
第２レジスト層に対する積層化第１レジスト層の
エツチング選択性を実質的に向上することができ
る。例えば第３図において、CCl4濃度50％の場
合の各レジスト膜のエツチレートはAZ−1350で
約250Å／分、PMMAで約660Å／分、FPMで約
1200Å／分である。したがつて第１レジスト層に
PMMA、第２レジスト層にAZ−1350を用いると
選択比は660／250＝2.64にしかならないが、第１
レジスト層をFPMとすれば4.80とより大きな選
択比が期待できる。ところがFRM層に直接AZ−
1350を塗布しようとするとAZ−1350の溶媒が
FPM膜を溶解してしまうため均一な２層レジス
ト構造を得ることができなかつた。そこでFPM
層の表面に極く薄くAZ−1350溶媒に溶けない有
機材料膜から成るバツフア層を形成した後、AZ
−1350層を形成すればこの問題は解決される。次
にバツフア層としてPMMA膜を用いた実施例を
示す。 Further, according to the spirit of the present invention, the first resist layer has a laminated structure consisting of two or more types of organic material thin films,
The etching selectivity of the stacked first resist layer relative to the second resist layer can be substantially improved. For example, in Figure 3, when the CCl 4 concentration is 50%, the etching rate of each resist film is approximately 250 Å/min for AZ-1350, approximately 660 Å/min for PMMA, and approximately 660 Å/min for FPM.
1200 Å/min. Therefore, the first resist layer
When PMMA and AZ-1350 are used for the second resist layer, the selectivity is only 660/250 = 2.64, but the first
If the resist layer is FPM, a higher selection ratio of 4.80 can be expected. However, AZ− directly to the FRM layer
When trying to apply 1350, the solvent of AZ-1350
Since the FPM film was dissolved, a uniform two-layer resist structure could not be obtained. So FPM
After forming a buffer layer on the surface of the layer consisting of an extremely thin film of organic material insoluble in AZ-1350 solvent,
Forming -1350 layers solves this problem. Next, an example will be shown in which a PMMA film is used as the buffer layer.
実施例 ５
基板上にFPMレジスト（膜厚8000Å）を塗布
し所定のベーキングを行つた後バツフア層として
PMMAを約1000Åの厚さに塗布し、更にAZ−
1350を約3000Åの厚さに塗布した。所定のベーキ
ングの後、紫外線密着露光・湿式現像処理により
所定のパターンをAZ−1350層に形成した。次に
O2＋CCl4（50％）で反応性イオンエツチングを行
つたところ、約８分のエツチングでPMMA＋
FPMの積層化第１レジスト層をパターン化でき
た。このときAZ−1350層の膜厚減少は約2000Å
であつた。一方第１レジスト層をPMMAの単層
（膜厚9000Å）とした試料では同一のエツチング
条件で約13分の処理を要した。しかしこの場合に
は第２レジスト層のAZ−1350パターンは完全に
消失し、更にPMMA層膜厚が約800Å減少してい
た。以上の結果からバツフア層を設けることで、
よりエツチング選択性の高い多層レジスト構造が
得られることが確められた。Example 5 FPM resist (8000 Å film thickness) was applied on the substrate, and after prescribed baking, it was used as a buffer layer.
Apply PMMA to a thickness of approximately 1000Å, and then apply AZ−
1350 was applied to a thickness of approximately 3000 Å. After prescribed baking, a prescribed pattern was formed on the AZ-1350 layer by ultraviolet contact exposure and wet development. next
When reactive ion etching was performed with O 2 + CCl 4 (50%), PMMA +
The first resist layer of FPM stacking could be patterned. At this time, the thickness reduction of the AZ-1350 layer is approximately 2000Å.
It was hot. On the other hand, a sample in which the first resist layer was a single layer of PMMA (thickness: 9000 Å) required approximately 13 minutes of etching under the same etching conditions. However, in this case, the AZ-1350 pattern of the second resist layer completely disappeared, and the thickness of the PMMA layer was further reduced by about 800 Å. From the above results, by providing a buffer layer,
It was confirmed that a multilayer resist structure with higher etching selectivity could be obtained.
また本発明の趣旨に従えば、第１レジスト層材
料としては、酸素ガスとハロゲン含有炭化水素化
合物ガスの混合ガスプラズマによるエツチレート
が第２レジスト層材料に比べて充分大きな有機材
料薄膜であればよい。特にPMMAやFPMに代表
されるポリメタクリレートを主鎖構造に持つ有機
材料膜は一般に放射線照射により容易に主鎖が切
断され低分子量化する傾向にあり、またCMSや
AZ1350に代表されるベンゼン環構造を有する有
機材料膜は逆に放射線耐性が強い傾向を持つの
で、酸素プラズマによるエツチングのされ易さに
違いがある。本発明においては酸素ガスに適量の
ハロゲン含有炭化水素化合物ガスを添加して、エ
ツチングと同時にポリマー化反応を競合的に起こ
させることにより両種材料間のエツチレート相対
比を顕著に増大させることができた。この場合の
添加ガスとしてはCF4等のフルオロカーボン系ガ
スでも効果が認められたが、ポリメタクリレート
系膜のエツチレートも添加量が多くなると極端に
低下するため、実用的にはメリツトが小さかつ
た。しかし第３図のごとくCCl4ガスを添加した
場合はポリメタクリレート系材料のエツチレート
がほとんど低下せず、且つベンゼン環構造を持つ
有機材料膜のエツチレートが０となる条件範囲が
広くなるのでCF4添加に比べて短時間のエツチン
グでパターン形成ができ、とりわけ効果的であつ
た。以上の結果からポリメタクリレートを主鎖構
造とする有機材料膜を第１層に、ベンゼン環構造
をもつレジスト膜を第２層に用いればCCl4ガス
を添加したガスプラズマにより高いエツチング選
択比を実現できる。また放射線感応性を有するレ
ジスト材料を第１レジスト層として積極的に用い
れば、基板表面に第１レジスト層を形成した後、
選択的露光・現像処理により特定の部分だけ第１
レジスト層を除去し、この上に薄く第２レジスト
層を形成して以下本発明の方法に従つて所要のパ
ターンを形成することもできる。このようにする
と、基板表面の凹凸は、上記した特定の部分につ
いては直接第２レジスト層で薄く覆われるだけで
平坦化せずに残ることになる。そこで電子ビーム
直接露光方法において位置合せマークパターンに
対応する基板表面凹凸部分にこの方法を適用すれ
ば、位置合せマークパターン段差からの反射電子
や２次電子線強度を充分大きくすることができ、
厚い第１レジスト層で平坦化した場合に比べ位置
合せマークパターン信号の検出が著しく容易にな
る。 Further, according to the spirit of the present invention, the first resist layer material may be any organic material thin film that can be etched by a mixed gas plasma of oxygen gas and a halogen-containing hydrocarbon compound gas in a manner that is sufficiently larger than that of the second resist layer material. . In particular, organic material films with a main chain structure of polymethacrylate, such as PMMA and FPM, tend to have their main chains easily cleaved and have a low molecular weight when exposed to radiation.
On the contrary, organic material films with a benzene ring structure, such as AZ1350, tend to have strong radiation resistance, so there is a difference in the ease with which they are etched by oxygen plasma. In the present invention, by adding an appropriate amount of halogen-containing hydrocarbon compound gas to oxygen gas to competitively cause a polymerization reaction at the same time as etching, the relative etching rate ratio between both materials can be significantly increased. Ta. As the additive gas in this case, fluorocarbon gas such as CF 4 was also found to be effective, but the etch rate of the polymethacrylate film also decreased dramatically as the amount added increased, so it had little practical merit. However, as shown in Figure 3, when CCl 4 gas is added, the etch rate of the polymethacrylate material hardly decreases, and the range of conditions in which the etch rate of the organic material film with a benzene ring structure becomes 0 becomes wider, so CF 4 is added. Pattern formation was possible in a shorter time compared to etching, which was particularly effective. From the above results, if an organic material film with a main chain structure of polymethacrylate is used as the first layer and a resist film with a benzene ring structure is used as the second layer, a high etching selectivity can be achieved using gas plasma added with CCl 4 gas. can. Furthermore, if a radiation-sensitive resist material is actively used as the first resist layer, after forming the first resist layer on the substrate surface,
Selective exposure and development process allows only specific areas to be exposed first.
It is also possible to remove the resist layer, form a thin second resist layer thereon, and then form a desired pattern according to the method of the present invention. In this way, the irregularities on the substrate surface will remain without being flattened, with the above-mentioned specific portions being directly covered with a thin layer of the second resist layer. Therefore, if this method is applied to the uneven portion of the substrate surface corresponding to the alignment mark pattern in the electron beam direct exposure method, the intensity of reflected electrons and secondary electron beams from the alignment mark pattern step can be sufficiently increased.
Detection of alignment mark pattern signals is significantly easier than in the case of flattening with a thick first resist layer.
以上説明したように、本発明方法によれば、レ
ジスト層の調製、膜厚、処理操作等の各点で従来
法より簡便化及び効率の向上を達成して、より精
度の高い微細パターンを形成することができるの
で、顕著な効果を有するものである。 As explained above, the method of the present invention is simpler and more efficient than conventional methods in terms of resist layer preparation, film thickness, processing operations, etc., and forms fine patterns with higher precision. Therefore, it has a remarkable effect.
第１図は、従来の２層レジストパターン形成方
法の工程図、第２図は本発明方法で使用する装置
の一例の概要図、第３図は、第２図に示した装置
を用いて得られた、O2＋CCl4混合ガス中のCCl4
濃度と各種レジストのエツチレートとの関係を示
すグラフである。
１：基板、２：第１レジスト層、３：第２レジ
スト層、４：放射線、５：感光領域、８：真空容
器、１２：高周波電源、１３：試料基板、１５：
排気管、１７：平行平板型上部電極、１８：平行
平板型下部電極、１９：プラズマ。
FIG. 1 is a process diagram of a conventional two-layer resist pattern forming method, FIG. 2 is a schematic diagram of an example of an apparatus used in the method of the present invention, and FIG. 3 is a process diagram of a conventional two-layer resist pattern forming method. CCl 4 in O 2 + CCl 4 mixed gas
3 is a graph showing the relationship between concentration and etching rate of various resists. 1: Substrate, 2: First resist layer, 3: Second resist layer, 4: Radiation, 5: Photosensitive area, 8: Vacuum container, 12: High frequency power source, 13: Sample substrate, 15:
Exhaust pipe, 17: parallel plate type upper electrode, 18: parallel plate type lower electrode, 19: plasma.
Claims (1)
主鎖構造とする有機材料層、更にその上にベンゼ
ン環構造を含有する有機レジスト材料層を有する
パターン形成材料に対して、該有機レジスト材料
層に対する放射線による選択的露光処理、及びそ
れに続く現像処理を含む処理により、該有機レジ
スト材料層をパターン化して所要のマスクパター
ンを形成する工程と、該マスクパターンをマスク
としたドライエツチング処理により該有機材料層
をパターン化する工程を含むパターン形成方法に
おいて、該ドライエツチング処理を、酸素ガス
と、CCl4ガスとを含有する混合ガスから生じさ
せた低温ガスプラズマを用いて行うことを特徴と
するパターン形成方法。1. For a pattern forming material having an organic material layer having a main chain structure of polymethacrylate on the surface of a predetermined substrate, and further an organic resist material layer containing a benzene ring structure thereon, radiation is applied to the organic resist material layer. A step of patterning the organic resist material layer to form a desired mask pattern by a process including a selective exposure process and a subsequent development process, and a dry etching process using the mask pattern as a mask to form the organic material layer. A pattern forming method comprising the step of patterning a pattern, characterized in that the dry etching process is performed using a low temperature gas plasma generated from a mixed gas containing oxygen gas and CCl 4 gas. .
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2876582A JPS58147033A (en) | 1982-02-26 | 1982-02-26 | Pattern formation |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2876582A JPS58147033A (en) | 1982-02-26 | 1982-02-26 | Pattern formation |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS58147033A JPS58147033A (en) | 1983-09-01 |
| JPH0234453B2 true JPH0234453B2 (en) | 1990-08-03 |
Family
ID=12257495
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2876582A Granted JPS58147033A (en) | 1982-02-26 | 1982-02-26 | Pattern formation |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS58147033A (en) |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS60263435A (en) * | 1984-06-11 | 1985-12-26 | Rohm Co Ltd | Patterning method |
| JPH01200628A (en) * | 1988-02-05 | 1989-08-11 | Toshiba Corp | Dry etching |
| JP2722768B2 (en) * | 1990-04-26 | 1998-03-09 | ソニー株式会社 | Etching method of multilayer resist layer |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS56135928A (en) * | 1980-03-27 | 1981-10-23 | Fujitsu Ltd | Forming method for pattern of silicone resin |
| JPS56140351A (en) * | 1980-04-04 | 1981-11-02 | Fujitsu Ltd | Formation of pattern |
-
1982
- 1982-02-26 JP JP2876582A patent/JPS58147033A/en active Granted
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS56135928A (en) * | 1980-03-27 | 1981-10-23 | Fujitsu Ltd | Forming method for pattern of silicone resin |
| JPS56140351A (en) * | 1980-04-04 | 1981-11-02 | Fujitsu Ltd | Formation of pattern |
Also Published As
| Publication number | Publication date |
|---|---|
| JPS58147033A (en) | 1983-09-01 |
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