JPH0815868A - Forming method of inorganic resist film - Google Patents
Forming method of inorganic resist filmInfo
- Publication number
- JPH0815868A JPH0815868A JP14427494A JP14427494A JPH0815868A JP H0815868 A JPH0815868 A JP H0815868A JP 14427494 A JP14427494 A JP 14427494A JP 14427494 A JP14427494 A JP 14427494A JP H0815868 A JPH0815868 A JP H0815868A
- Authority
- JP
- Japan
- Prior art keywords
- film
- resist
- inorganic resist
- resist film
- electron beam
- 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.)
- Granted
Links
- 238000000034 method Methods 0.000 title claims description 16
- 238000010894 electron beam technology Methods 0.000 claims abstract description 42
- 239000000758 substrate Substances 0.000 claims abstract description 23
- KLZUFWVZNOTSEM-UHFFFAOYSA-K Aluminum fluoride Inorganic materials F[Al](F)F KLZUFWVZNOTSEM-UHFFFAOYSA-K 0.000 claims abstract description 5
- IRPGOXJVTQTAAN-UHFFFAOYSA-N 2,2,3,3,3-pentafluoropropanal Chemical compound FC(F)(F)C(F)(F)C=O IRPGOXJVTQTAAN-UHFFFAOYSA-N 0.000 claims abstract description 4
- 229910052744 lithium Inorganic materials 0.000 claims description 5
- 150000004820 halides Chemical class 0.000 claims description 3
- OYPRJOBELJOOCE-UHFFFAOYSA-N Calcium Chemical compound [Ca] OYPRJOBELJOOCE-UHFFFAOYSA-N 0.000 claims description 2
- WHXSMMKQMYFTQS-UHFFFAOYSA-N Lithium Chemical compound [Li] WHXSMMKQMYFTQS-UHFFFAOYSA-N 0.000 claims description 2
- FYYHWMGAXLPEAU-UHFFFAOYSA-N Magnesium Chemical compound [Mg] FYYHWMGAXLPEAU-UHFFFAOYSA-N 0.000 claims description 2
- 239000000654 additive Substances 0.000 claims description 2
- 230000000996 additive effect Effects 0.000 claims description 2
- 229910052788 barium Inorganic materials 0.000 claims description 2
- DSAJWYNOEDNPEQ-UHFFFAOYSA-N barium atom Chemical compound [Ba] DSAJWYNOEDNPEQ-UHFFFAOYSA-N 0.000 claims description 2
- 229910052791 calcium Inorganic materials 0.000 claims description 2
- 239000011575 calcium Substances 0.000 claims description 2
- 229910052749 magnesium Inorganic materials 0.000 claims description 2
- 239000011777 magnesium Substances 0.000 claims description 2
- 229910021645 metal ion Inorganic materials 0.000 claims description 2
- 229910052712 strontium Inorganic materials 0.000 claims description 2
- CIOAGBVUUVVLOB-UHFFFAOYSA-N strontium atom Chemical compound [Sr] CIOAGBVUUVVLOB-UHFFFAOYSA-N 0.000 claims description 2
- PQXKHYXIUOZZFA-UHFFFAOYSA-M lithium fluoride Chemical compound [Li+].[F-] PQXKHYXIUOZZFA-UHFFFAOYSA-M 0.000 abstract description 15
- VTJUKNSKBAOEHE-UHFFFAOYSA-N calixarene Chemical compound COC(=O)COC1=C(CC=2C(=C(CC=3C(=C(C4)C=C(C=3)C(C)(C)C)OCC(=O)OC)C=C(C=2)C(C)(C)C)OCC(=O)OC)C=C(C(C)(C)C)C=C1CC1=C(OCC(=O)OC)C4=CC(C(C)(C)C)=C1 VTJUKNSKBAOEHE-UHFFFAOYSA-N 0.000 abstract description 14
- 239000002245 particle Substances 0.000 abstract description 9
- 229910052710 silicon Inorganic materials 0.000 abstract description 5
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 abstract description 4
- 239000010419 fine particle Substances 0.000 abstract description 4
- 239000010703 silicon Substances 0.000 abstract description 4
- 238000006243 chemical reaction Methods 0.000 abstract description 2
- 230000001678 irradiating effect Effects 0.000 abstract description 2
- 230000003247 decreasing effect Effects 0.000 abstract 2
- 229920003229 poly(methyl methacrylate) Polymers 0.000 description 10
- 239000004926 polymethyl methacrylate Substances 0.000 description 10
- 230000035945 sensitivity Effects 0.000 description 10
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 5
- 239000004793 Polystyrene Substances 0.000 description 5
- 229910052782 aluminium Inorganic materials 0.000 description 5
- 230000015572 biosynthetic process Effects 0.000 description 5
- 229910052799 carbon Inorganic materials 0.000 description 5
- 238000000354 decomposition reaction Methods 0.000 description 5
- 238000000151 deposition Methods 0.000 description 5
- 230000008021 deposition Effects 0.000 description 5
- 238000004519 manufacturing process Methods 0.000 description 5
- 229910052760 oxygen Inorganic materials 0.000 description 5
- 229920002223 polystyrene Polymers 0.000 description 5
- MVPPADPHJFYWMZ-UHFFFAOYSA-N chlorobenzene Chemical compound ClC1=CC=CC=C1 MVPPADPHJFYWMZ-UHFFFAOYSA-N 0.000 description 4
- 239000013078 crystal Substances 0.000 description 4
- 230000000694 effects Effects 0.000 description 4
- 229910004298 SiO 2 Inorganic materials 0.000 description 3
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 3
- 238000007796 conventional method Methods 0.000 description 3
- 239000007789 gas Substances 0.000 description 3
- 238000001459 lithography Methods 0.000 description 3
- 239000000463 material Substances 0.000 description 3
- 239000001301 oxygen Substances 0.000 description 3
- 230000007261 regionalization Effects 0.000 description 3
- 238000004544 sputter deposition Methods 0.000 description 3
- 238000007740 vapor deposition Methods 0.000 description 3
- 229910016569 AlF 3 Inorganic materials 0.000 description 2
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 2
- 230000005540 biological transmission Effects 0.000 description 2
- 238000000609 electron-beam lithography Methods 0.000 description 2
- 238000005530 etching Methods 0.000 description 2
- 239000012528 membrane Substances 0.000 description 2
- 229910052757 nitrogen Inorganic materials 0.000 description 2
- 238000009832 plasma treatment Methods 0.000 description 2
- YCKRFDGAMUMZLT-UHFFFAOYSA-N Fluorine atom Chemical compound [F] YCKRFDGAMUMZLT-UHFFFAOYSA-N 0.000 description 1
- 229910052581 Si3N4 Inorganic materials 0.000 description 1
- 230000001133 acceleration Effects 0.000 description 1
- 150000001875 compounds Chemical class 0.000 description 1
- 238000004132 cross linking Methods 0.000 description 1
- 238000005520 cutting process Methods 0.000 description 1
- 238000003795 desorption Methods 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 238000001704 evaporation Methods 0.000 description 1
- 230000008020 evaporation Effects 0.000 description 1
- 239000011737 fluorine Substances 0.000 description 1
- 229910052731 fluorine Inorganic materials 0.000 description 1
- 229910052732 germanium Inorganic materials 0.000 description 1
- GNPVGFCGXDBREM-UHFFFAOYSA-N germanium atom Chemical compound [Ge] GNPVGFCGXDBREM-UHFFFAOYSA-N 0.000 description 1
- 150000002366 halogen compounds Chemical class 0.000 description 1
- 238000011065 in-situ storage Methods 0.000 description 1
- 230000003993 interaction Effects 0.000 description 1
- 238000001659 ion-beam spectroscopy Methods 0.000 description 1
- 125000002496 methyl group Chemical group [H]C([H])([H])* 0.000 description 1
- 230000003287 optical effect Effects 0.000 description 1
- 239000011368 organic material Substances 0.000 description 1
- 239000005022 packaging material Substances 0.000 description 1
- 238000000059 patterning Methods 0.000 description 1
- HQVNEWCFYHHQES-UHFFFAOYSA-N silicon nitride Chemical compound N12[Si]34N5[Si]62N3[Si]51N64 HQVNEWCFYHHQES-UHFFFAOYSA-N 0.000 description 1
Landscapes
- Photosensitive Polymer And Photoresist Processing (AREA)
- Compounds Of Alkaline-Earth Elements, Aluminum Or Rare-Earth Metals (AREA)
Abstract
Description
【０００１】[0001]
【産業上の利用分野】本発明は無機レジスト膜の形成方
法に関するものである。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for forming an inorganic resist film.
【０００２】[0002]
【従来の技術】近年の量子効果素子等の製造ではナノメ
ートル（nm）程度のレジストパターン形成を行う事が必
要となっている。しかし、光学露光では、その波長が空
間分解能を制限していて、ナノメートル程度のリソグラ
フィは原理的に不可能である。これに対して電子線露光
方式では、その電子線径が１nm以下まで達し、これを用
いたリソグラフィは極めて有望である。この電子線露光
方式で通常用いられるのがポリメチルメタクリレート
（ＰＭＭＡ）等有機レジストである。この分解能限界は
約１０nm程度とされている。これらの有機レジストの露
光感度は高く、感光するための電子線エネルギーのしき
い値は約５ｅＶ程度と考えられている。しかしこの高感
度故に、レジスト膜中、もしくは基板からの後方散乱電
子や、２次電子によっても感光し、実質的な分解能が制
限される。2. Description of the Related Art In recent years in manufacturing quantum effect devices and the like, it is necessary to form a resist pattern of about nanometer (nm). However, in optical exposure, the wavelength limits the spatial resolution, and lithography on the order of nanometers is impossible in principle. On the other hand, in the electron beam exposure method, the electron beam diameter reaches 1 nm or less, and lithography using this is extremely promising. An organic resist such as polymethyl methacrylate (PMMA) is usually used in the electron beam exposure method. This resolution limit is about 10 nm. The exposure sensitivity of these organic resists is high, and the threshold value of the electron beam energy for exposure is considered to be about 5 eV. However, because of this high sensitivity, it is also exposed to backscattered electrons or secondary electrons in the resist film or from the substrate, and practical resolution is limited.
【０００３】ところが、近年の単一電子トンネル素子を
はじめとする量子効果素子形成では数nm程度のパターン
形成が必要とされ、有機レジストでの分解能を越えるパ
ターン形成技術が求められている。このようなnmオーダ
ーでのリソグラフィとしては、ＡｌＦ3 等のハロゲン化
合物の無機レジストを電子線露光する事で実現され、例
えばジャパン・ジャーナル・オブ・アプライド・フィジ
ックス（Ｊｐｎ．Ｊ．Ａｐｐｌ．Ｐｈｙｓ．）３２巻６
２１８頁には、１０nm程度のパターン形成とリフトオフ
パターン形成についての可能性が示されている。通常こ
の電子線による無機レジスト膜露光では、透過型電子顕
微鏡が用いられる。１００−２００ＫＶの高加速電子線
が描画に用いられ、電子線照射によるレジスト膜の分解
脱離反応によってレジストパターン形成がその場で起こ
る。例えば、ＡｌＦ3 をレジスト材とした場合、フッ素
が蒸発してポジ型のパターン形成が起こる。この分解反
応のしきい値は高く１５ｅＶ以上あり、２次電子による
影響はきわめて少ない。このように、透過電子顕微鏡を
用いた場合パターン幅は電子ビーム径に依存し、ビーム
径を絞ることで高分解能のレジストパターン形成が可能
である。However, in recent years, formation of a quantum effect element such as a single electron tunnel element requires a pattern formation of about several nm, and a pattern formation technique exceeding the resolution of an organic resist is required. Such lithography on the order of nm is realized by exposing an inorganic resist of a halogen compound such as AlF 3 to electron beam exposure. For example, Japan Journal of Applied Physics (Jpn. 32 rolls 6
On page 218, the possibility of forming a pattern of about 10 nm and forming a lift-off pattern is shown. Usually, in the exposure of the inorganic resist film by the electron beam, a transmission electron microscope is used. A high-acceleration electron beam of 100 to 200 KV is used for writing, and a resist pattern is formed in situ by a decomposition and desorption reaction of the resist film by the irradiation of the electron beam. For example, when AlF 3 is used as a resist material, fluorine evaporates, and a positive pattern is formed. The threshold value of this decomposition reaction is as high as 15 eV or more, and the influence of secondary electrons is extremely small. As described above, when the transmission electron microscope is used, the pattern width depends on the electron beam diameter, and a high-resolution resist pattern can be formed by reducing the beam diameter.
【０００４】[0004]
【発明が解決しようとする課題】しかし、電子を透過さ
せるために必然的に極めて薄い窒化硅素等のメンブレン
を基板として用いなくてはならない制約がある。このメ
ンブレンは極めて脆く、基板として用いることのできる
実効的な面積は約１mm角と極めて狭い。このため耐久
性、量産性、さらに、位置合わせ等において、実用上多
くの問題をかかえている。これに対して、走査型の電子
線を用いた電子線露光は通常の集積回路製造用基板と同
じＳｉ基板を用いることができ、その耐久性、位置合わ
せ等において実用上大変優れている。しかし、この走査
型電子線を用いた無機レジスト露光では、カーボンの堆
積が優先しこれまで、実用的な無機レジスト膜のパター
ン形成が報告されていない。However, there is a restriction that an extremely thin membrane such as silicon nitride must be used as a substrate in order to transmit electrons. This membrane is extremely brittle, and the effective area that can be used as a substrate is extremely narrow, about 1 mm square. Therefore, there are many practical problems in durability, mass productivity, alignment, and the like. On the other hand, electron beam exposure using a scanning electron beam can use the same Si substrate as a normal integrated circuit manufacturing substrate, and is extremely excellent in practical use in terms of durability and alignment. However, in this inorganic resist exposure using a scanning electron beam, carbon deposition is prioritized, and no pattern formation of a practical inorganic resist film has been reported so far.
【０００５】本発明者は研究の結果、レジスト膜の分解
反応速度が粒子形状に大きく依存する事を突き止めた。As a result of research, the present inventors have found that the decomposition reaction rate of a resist film greatly depends on the particle shape.
【０００６】まず、無機レジストにおける従来方法での
問題点を以下に述べる。基板としてＳｉ基板を用い、こ
の上に無機レジストを蒸着もしくはスパッタ法でレジス
ト膜形成を行うと、Ｓｉ基板とレジスト材料との間の表
面張力の違いと、基板表面の結晶面に引きずられて、無
機レジスト膜は基板面に結晶成長し図２に示すような大
きな島４を形成して成長する。これらの大きな粒子によ
って構成された無機レジスト膜の露光感度は低く、カー
ボン堆積との競合に負けて、電子線描画によってカーボ
ン堆積が観測される。すなわち、従来の加速電圧の低い
走査型電子線では無機レジストの直接描画が極めて困難
であった。First, problems of the inorganic resist in the conventional method will be described below. When a Si substrate is used as a substrate and a resist film is formed thereon by vapor deposition or a sputtering method of an inorganic resist, the difference in surface tension between the Si substrate and the resist material and the drag on the crystal plane of the substrate surface, The inorganic resist film grows by crystallizing on the substrate surface to form large islands 4 as shown in FIG. Exposure sensitivity of the inorganic resist film composed of these large particles is low, and carbon deposition is observed by electron beam lithography, losing the competition with carbon deposition. That is, it is extremely difficult to directly draw an inorganic resist with a conventional scanning electron beam having a low acceleration voltage.
【０００７】一方、Ｓｉ基板等の結晶面を直接使わず
に、ＳｉＯ2 もしくはＳｉ3 Ｎ4 のような特定結晶面を
持たないアモルファス膜上に無機レジスト膜を成長させ
ると、図２に示すように無機レジスト４は初期に島状成
長４がおこるものの、その後不特定面を持った微粒子を
形成しながら成長する。このような、微粒子によって形
成される無機レジスト膜は電子線露光感度が高く、カー
ボンの堆積との競合に勝って走査型電子線の直接描画が
可能となる。しかし、レジスト膜の底には電子線露光感
度の低い部分つまり初期の島状成長の部分が残留してい
るので、この部分はその上がポジ型に感光して蒸発して
も未露光で残留し、完全なパターン形成が困難である。
また、ＳｉＯ2 、Ｓｉ3 Ｎ4 上に（（Ｌｉ，Ａｌ）Ｆ）
を形成して電子線を照射すると、ＳｉとＯ，Ｎの結合が
切れ、ＯやＮがガスとしてＬｉと反応してしまう。On the other hand, when an inorganic resist film is grown on an amorphous film having no specific crystal plane such as SiO 2 or Si 3 N 4 without directly using a crystal plane such as a Si substrate, as shown in FIG. Although the inorganic resist 4 initially grows in island form, it grows while forming fine particles having an unspecified surface. Such an inorganic resist film formed of fine particles has a high electron beam exposure sensitivity, and can directly draw a scanning electron beam over a competition with carbon deposition. However, a portion having low electron beam exposure sensitivity, that is, a portion of the initial island growth, remains at the bottom of the resist film, and even if this portion is exposed to a positive mold and evaporated, it remains unexposed. However, it is difficult to form a complete pattern.
Further, ((Li, Al) F) is formed on SiO 2 and Si 3 N 4.
When the electron beam is formed and irradiated with an electron beam, the bond between Si and O and N is broken, and O and N react with Li as a gas.
【０００８】従来の有機レジストや無機レジスト技術で
はナノメートルオーダーでのサスペンデッド型マスクの
形成が非常に困難であった。サスペンデット型マスクは
図３ｄに示すように、パターン幅（形状）を規定するた
めの上部のマスクとこれをオーバーハングになるように
支える柱（下部有機膜）から成る。まず従来法について
説明する。従来法では３層レジストが用いられ、下部有
機膜としてＰＭＭＡ（ポリメチルメタクリレート）、中
間層としてＧｅ（ゲルマニウム）、上部レジスト膜とし
てＰＭＭＡ等を組み合わせて形成する。このような３層
構造レジスト膜に対して電子線リソグラフィ技術を用い
て上部ＰＭＭＡのパターン形成を行う。次に、上部ＰＭ
ＭＡ上に形成されたパターンをＥＣＲエッチング等を用
いて中間のＧｅ層にパターン転写を行う。最後に、酸素
プラズマ等による等方エッチングを用いて上部ＰＭＭＡ
層の除去、および下部ＰＭＭＡ層のオーバーハング形成
を行いサスペンデッド型マスクの形成が完了する。ここ
で問題になるのは、ＰＭＭＡの解像度限界により、２０
nm以下のパターン形成が極めて困難な事である。この問
題に対して中間Ｇｅ層と上部ＰＭＭＡに変えて、無機レ
ジストを適用する事で解像度限界を実質的には電子ビー
ム径まで改善する事が可能となるが、サスペンデッド構
造を形成する上でさらに困難が生じる。有機膜は電子線
照射に対して何等かの相互作用（チェーン切断、クロス
リンク）が起こる。特に無機レジスト膜の直接描画に必
要な高い電子線ドーズを必要とする条件では下地の有機
膜のチェーン切断が顕著におこり、膜の体積減少やガス
の発生が顕著に起こる。このために無機レジストの描画
中に無機レジスト膜の陥没や、発生したガスによる無機
レジスト膜の破裂等の現象が見られ、実際にはサスペン
デッド型マスクの構造の形成が極めて困難である。[0008] It has been very difficult to form a suspended mask on the order of nanometers using conventional organic resist or inorganic resist technology. As shown in FIG. 3D, the suspended mask includes an upper mask for defining a pattern width (shape) and columns (lower organic film) that support the mask so as to be overhang. First, the conventional method will be described. In the conventional method, a three-layer resist is used. PMMA (polymethylmethacrylate) is used as the lower organic film, Ge (germanium) is used as the intermediate layer, and PMMA is used as the upper resist film in combination. An upper PMMA pattern is formed on such a three-layer resist film by using an electron beam lithography technique. Next, the upper PM
The pattern formed on the MA is transferred to an intermediate Ge layer using ECR etching or the like. Finally, the upper PMMA is formed by isotropic etching using oxygen plasma or the like.
The layer is removed and the lower PMMA layer is overhanged to complete the formation of the suspended mask. The problem here is that due to the resolution limit of PMMA, 20
It is extremely difficult to form a pattern of nm or less. To solve this problem, the resolution limit can be substantially improved to the electron beam diameter by applying an inorganic resist instead of the intermediate Ge layer and the upper PMMA. However, in forming the suspended structure, Difficulties arise. The organic film undergoes some kind of interaction (chain cutting, cross linking) with electron beam irradiation. In particular, under conditions that require a high electron beam dose required for direct writing of the inorganic resist film, the chain of the underlying organic film is significantly cut, resulting in a significant decrease in film volume and gas generation. For this reason, phenomena such as depression of the inorganic resist film and rupture of the inorganic resist film due to generated gas are observed during drawing of the inorganic resist, and it is actually extremely difficult to form the structure of the suspended mask.
【０００９】本発明の目的は、基板上に形成される極め
て薄い無機レジスト膜中の粒径を可能な限り小さく押さ
える事で、分解反応に対するカーボン堆積率を極力抑
え、数十ＫＶ程度の走査型電子線の比較的低い加速電子
線によってでも無機レジスト膜の直接描画を可能とする
無機レジストの形成方法を提供することである。また、
量子効果素子等への応用上極めて重要なサスペンデッド
型マスクの形成方法についても具体的な方法を提供する
ことである。SUMMARY OF THE INVENTION It is an object of the present invention to suppress the carbon deposition rate against the decomposition reaction as much as possible by minimizing the particle size in an extremely thin inorganic resist film formed on a substrate, and to achieve a scanning type of about several tens of KV. An object of the present invention is to provide a method of forming an inorganic resist which enables direct writing of an inorganic resist film even with an accelerated electron beam having a relatively low electron beam. Also,
Another object of the present invention is to provide a specific method for forming a suspended mask, which is extremely important for application to quantum effect devices and the like.
【００１０】[0010]
【課題を解決するための手段】本発明は ＭＦX （Ｍは
リチウム、マグネシウム、ストロンチウム、カルシウ
ム、バリウム、アルミニウム等の金属イオン）で表示さ
れるハロゲン化物による無機レジスト膜の形成方法にお
いて、このハロゲン化物にフッ化アルミニウムを添加剤
として加え、これを蒸着法もしくは、スパッタ法におい
て基板上にレジスト膜を形成する方法で、ポリスチレ
ン、カリックスアレン等の有機膜を下地層とし、この有
機膜下地層に対して無機レジスト膜形成前に電子線照射
による前処理を行う事を特徴とする無機レジスト膜形成
方法である。The present invention relates to a method for forming an inorganic resist film using a halide represented by MF x (M is a metal ion such as lithium, magnesium, strontium, calcium, barium and aluminum). Aluminum fluoride as an additive to the compound, and by vapor deposition or by a method of forming a resist film on the substrate by the sputtering method, an organic film such as polystyrene or calixarene is used as an underlayer, On the other hand, it is a method for forming an inorganic resist film, which comprises performing a pretreatment by electron beam irradiation before forming the inorganic resist film.
【００１１】無機レジストにおける描画パターンの空間
分解能は実質的に電子線のビーム径で決定され、それは
有機レジストで得られる分解能をはるかに凌ぐものであ
る。しかしながら、レジスト膜の露光には数十〜数Ｃ／
cm2 の電子線ドーズが必要とされる。このような特性を
持つ無機レジストをデバイス生産、特に量子効果デバイ
ス作成に応用するには、無機レジストの露光感度を改善
する事と、サスペンデッド型マスクの下地材料の形成技
術が重要となる。本発明により、非晶質でしかも電子線
耐性の高いポリスチレン、カリックスアレン等を下地層
とすることで、無機レジスト膜形成初期に起こる島成長
が抑制され電子線露光感度の高い無機レジストが形成さ
れる。また、サスペンデッド型マスクの形成については
本発明における電子線耐性、耐熱性の高い、ポリスチレ
ン、カリックスアレン等の有機材料を下地膜とし、さら
に無機レジスト膜形成前に下地膜に対して５０００μＣ
／cm2 程度の電子線照射を与える事により、下地層は無
機レジスト直接描画に必要な電子線ドーズにおいても、
その形状変化はほとんど無視しうる程度に押さえられ
る。The spatial resolution of a pattern written on an inorganic resist is substantially determined by the beam diameter of an electron beam, which far exceeds the resolution obtained with an organic resist. However, several tens to several C /
An electron beam dose of cm 2 is required. In order to apply an inorganic resist having such characteristics to device production, particularly to quantum effect device fabrication, it is important to improve the exposure sensitivity of the inorganic resist and to form a base material for a suspended mask. According to the present invention, an inorganic resist having a high electron beam exposure sensitivity is formed by suppressing the island growth occurring at the initial stage of inorganic resist film formation by using an amorphous and high electron beam resistant polystyrene, calixarene or the like as a base layer. You. The suspended mask is formed by using an organic material such as polystyrene or calixarene having high electron beam resistance and heat resistance according to the present invention as a base film.
/ Cm 2 electron beam irradiation enables the underlayer to be exposed to the electron beam dose required for inorganic resist direct writing.
The change in shape is almost negligible.
【００１２】[0012]
【実施例】以下に、フッ化リチウム（ＬｉＦ）を母体と
したフッ化アルミニウム（ＡｌＦ3 ）を混合した無機レ
ジストの場合についての形成方法の詳細を調べる。The details of the method of forming an inorganic resist mixed with aluminum fluoride (AlF 3 ) based on lithium fluoride (LiF) will be examined below.
【００１３】まず、室温で蒸着もしくはスパッタ法で形
成されたフッ化リチウム膜は、３０〜１００nm程度の結
晶粒が成長する。また、フッ化リチウムの電子線に対す
る露光感度は１０4 〜１０5 μＣ／cm2 程度である。こ
れに対してフッ化アルミニウム膜はアモルファス状であ
り、その露光感度は１０7 〜１０8 μＣ／cm2 とかなり
悪い。ここで、フッ化リチウムに約１０〜２０％程度フ
ッ化リチウムを添加する事では露光感度はフッ化リチウ
ムのそれとほぼ変わらずに、粒径を２０nm程度まで小さ
くすることができる。以下ではＡｌをＬｉの約１０％混
入した場合を例にとって説明する。First, in a lithium fluoride film formed by vapor deposition or sputtering at room temperature, crystal grains of about 30 to 100 nm grow. The exposure sensitivity of lithium fluoride to electron beams is about 10 4 to 10 5 μC / cm 2 . On the other hand, the aluminum fluoride film is amorphous and its exposure sensitivity is 10 7 to 10 8 μC / cm 2, which is considerably poor. Here, by adding about 10 to 20% lithium fluoride to lithium fluoride, the exposure sensitivity is almost the same as that of lithium fluoride, and the particle size can be reduced to about 20 nm. Hereinafter, a case where Al is mixed in about 10% of Li will be described as an example.
【００１４】ポリスチレン、カリックスアレン（（ＣＨ
3 Ｃ6 Ｈ2 ＯＣＯＣＨ3 ＣＨ2 ）6）等の有機膜を最初
に形成することにより、膜成長初期から極めて微細な粒
で構成された良好なレジスト膜成長がおこる。図１に示
す実施例では、シリコン基板１上にカリックスアレン膜
２を形成しその後（Ｌｉ，Ａｌ）ＦX 膜３を形成した例
である。カリックスアレン膜２は、０．５Ｗ％濃度のク
ロルベンゼン溶液を回転数５０００ｒｐｍでスピンコー
ト塗布した。このときのカリックスアレン膜の膜厚は約
１０nmである。この後に、イオンビームスパッタ法で
（Ｌｉ，Ａｌ）ＦX を２０nm形成した。この場合膜中の
平均粒径は約３nm程度である。Polystyrene, calixarene ((CH
By forming an organic film such as 3 C 6 H 2 OCOCH 3 CH 2 ) 6 ) first, good resist film growth composed of extremely fine grains occurs from the initial stage of film growth. In the embodiment shown in FIG. 1, a subsequently formed calixarene film 2 on the silicon substrate 1 (Li, Al) example of forming a F X film 3. The calixarene film 2 was spin-coated with a 0.5 W% chlorobenzene solution at a rotation speed of 5000 rpm. At this time, the calixarene film has a thickness of about 10 nm. Thereafter, an ion beam sputtering method (Li, Al) and F X to 20nm formed. In this case, the average particle size in the film is about 3 nm.
【００１５】このレジスト膜に対して、電子線エネルギ
ー２０ＫｅＶ、１ｎＡの電流、及び電子線径１．５nmで
露光した場合、ラインドーズで０．２μＣ／cm2 程度で
ポジ型の直接描画ができた。このときの分解能は６０nm
ピッチで５nm線幅のラインアンドスペースが十分なコン
トラストをもって描画する事ができた。さらに、レジス
ト膜成長時の基板温度を下げることで粒子の大きさを下
げることができ、電子線のビーム径を絞ることで、さら
に微細パターンの生成が可能である。この後に、酸素プ
ラズマ処理で無機レジストパターンの下部にある有機膜
の下地層を局所的に除去し、ナノメートルオーダーのレ
ジストパターン転写が可能である。When this resist film was exposed with an electron beam energy of 20 KeV, a current of 1 nA and an electron beam diameter of 1.5 nm, a positive type direct drawing could be performed at a line dose of about 0.2 μC / cm 2 . . The resolution at this time is 60 nm
A line and space having a line width of 5 nm at a pitch could be drawn with sufficient contrast. Furthermore, the size of the particles can be reduced by lowering the substrate temperature during the growth of the resist film, and a finer pattern can be generated by narrowing the beam diameter of the electron beam. After that, the underlayer of the organic film under the inorganic resist pattern is locally removed by oxygen plasma treatment, and the resist pattern transfer on the nanometer order is possible.
【００１６】さらに、サスペンデッドマスクのような下
地の有機膜にある程度の厚みが必要とされる場合には、
無機レジスト膜形成前にも下地膜に対して電子線照射を
する事で無機レジスト描画時の高電子線ドーズに対して
も有機膜の形状変化を回避する事ができる。Further, when a certain thickness is required for an underlying organic film such as a suspended mask,
By irradiating the underlying film with an electron beam even before the formation of the inorganic resist film, it is possible to avoid a change in the shape of the organic film even with a high electron beam dose at the time of drawing the inorganic resist.
【００１７】ここでも、カリックスアレンを用いて実施
例を説明する。下地膜の形成では、カリックスアレン２
Ｗ％のクロルベンゼン溶液を５０００ｒｐｍのスピンコ
ートを３０秒行った。この時カリックスアレン膜の膜厚
は約１００nmとなる。つぎに、電子線照射条件として２
０ＫＶ、１０μＡのブロードビームを膜面に垂直に照射
し、トータルドーズが約５０００μＣ／cm2 となるよう
にした。このような電子線照射により、膜は５％ほどの
体積減少がみられる。この原因としてはカリックスアレ
ンに含まれるメチル基の分解・蒸発による体積減少等が
考えられる。この下地層の上に無機レジストを２０nm形
成し、３×１０5 μＣ／cm2 程度のドーズ量で露光する
事により無機レジストのパターニングが下地層の変形を
伴うことなく実現できた。この露光工程の後に図３−ｂ
に示す様に酸素プラズマ処理を行うことで下地層とした
カリックスアレン膜の等方エッチングをする事ができ、
サスペンデッドマスクを形成する事ができた。このよう
なマスク構造は下地層としてポリスチレンを用いた場合
でも同様に形成する事ができた。このようにして形成さ
れたサスペンデッド型マスクを用いることにより、良好
なアルミニウムのパターン転写ができた。なお、実施例
ではＬｉＦを用いたが、ＭｇＦ，ＳｒＦ，Ｃａｆ，Ｂａ
Ｆ等を用いることができる。Here, the embodiment will be described using calixarene. In forming the underlayer, calixarene 2
A W% chlorobenzene solution was spin-coated at 5000 rpm for 30 seconds. At this time, the calixarene film has a thickness of about 100 nm. Next, as the electron beam irradiation condition, 2
The film surface was irradiated with a broad beam of 0 KV and 10 μA vertically so that the total dose was about 5000 μC / cm 2 . By such electron beam irradiation, the volume of the film is reduced by about 5%. This may be due to a decrease in volume due to decomposition and evaporation of the methyl group contained in calixarene. By forming an inorganic resist on this underlayer with a thickness of 20 nm and exposing it with a dose of about 3 × 10 5 μC / cm 2 , patterning of the inorganic resist was realized without deformation of the underlayer. After this exposure step, FIG.
By performing the oxygen plasma treatment as shown in the figure, the calixarene film serving as the underlayer can be isotropically etched.
A suspended mask could be formed. Such a mask structure could be similarly formed even when polystyrene was used as the underlayer. By using the suspended mask formed in this way, good aluminum pattern transfer was achieved. Although LiF was used in the example, MgF, SrF, Caf, and Ba were used.
F or the like can be used.
【００１８】[0018]
【発明の効果】以上の様に本発明を応用する事により、
従来極めて困難であったナノメートルサイズの無機レジ
ストパターン形成を、特殊な基板を必要とせず、通常の
シリコン等の基板上に走査型電子描画装置で形成可能と
なる。また極微細パターンのサスペンデッド型マスクを
容易に形成する事が可能となり、デバイス作成上極めて
有効である。By applying the present invention as described above,
The formation of a nanometer-sized inorganic resist pattern, which has been extremely difficult in the past, can be formed on a substrate such as ordinary silicon by a scanning electronic drawing apparatus without requiring a special substrate. In addition, a suspended type mask having an extremely fine pattern can be easily formed, which is extremely effective in device fabrication.
【図１】本発明の実施例を説明する断面図である。FIG. 1 is a sectional view illustrating an embodiment of the present invention.
【図２】従来例を説明する断面図である。FIG. 2 is a cross-sectional view illustrating a conventional example.
【図３】オーバーハング構造を有したサスペンデッド型
マスクを形成した試料の断面構造を示す図である。FIG. 3 is a diagram showing a cross-sectional structure of a sample on which a suspended mask having an overhang structure is formed.
１ シリコン基板 ２ 有機膜下地層 ３ 無機レジスト層 ４ 島状成長した無機レジスト層 ５ 無機レジストの微粒子層 ６ ＳｉＯ2 下地層Reference Signs List 1 silicon substrate 2 organic film base layer 3 inorganic resist layer 4 inorganic resist layer grown in island form 5 inorganic resist fine particle layer 6 SiO 2 base layer
Claims (2)
トロンチウム、カルシウム、バリウム等の金属イオン）
で表示されるハロゲン化物による無機レジスト膜の形成
方法において、このハロゲン化物にフッ化アルミニウム
を添加剤として加え、これを基板上にレジスト膜として
形成する方法であって、有機膜を下地層とした上に前記
無機レジスト膜を形成する事を特徴とする無機レジスト
膜形成方法。1. MF X (M is a metal ion such as lithium, magnesium, strontium, calcium and barium)
In the method for forming an inorganic resist film using a halide represented by, aluminum fluoride is added as an additive to this halide, and this is formed as a resist film on a substrate, and an organic film is used as a base layer. A method for forming an inorganic resist film, comprising forming the inorganic resist film on the above.
形成前に電子線照射による前処理を行う事を特徴とする
請求項１に記載の無機レジスト膜形成方法。2. The method for forming an inorganic resist film according to claim 1, wherein a pretreatment by electron beam irradiation is performed on the underlayer of the organic film before forming the inorganic resist film.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP14427494A JP2630260B2 (en) | 1994-06-27 | 1994-06-27 | Method for forming inorganic resist film |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP14427494A JP2630260B2 (en) | 1994-06-27 | 1994-06-27 | Method for forming inorganic resist film |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH0815868A true JPH0815868A (en) | 1996-01-19 |
| JP2630260B2 JP2630260B2 (en) | 1997-07-16 |
Family
ID=15358283
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP14427494A Expired - Lifetime JP2630260B2 (en) | 1994-06-27 | 1994-06-27 | Method for forming inorganic resist film |
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| Country | Link |
|---|---|
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Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2010021347A1 (en) * | 2008-08-20 | 2010-02-25 | 富士通株式会社 | Material for forming resist-sensitizing film and method for manufacturing semiconductor device |
| EP2527852A3 (en) * | 2006-08-01 | 2014-08-20 | Washington University | Multifunctional nanoscopy for imaging cells |
| US9111838B2 (en) | 2010-01-08 | 2015-08-18 | Washington University | Method and apparatus for high resolution photon detection based on extraordinary optoconductance (EOC) effects |
-
1994
- 1994-06-27 JP JP14427494A patent/JP2630260B2/en not_active Expired - Lifetime
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP2527852A3 (en) * | 2006-08-01 | 2014-08-20 | Washington University | Multifunctional nanoscopy for imaging cells |
| US9453809B2 (en) | 2006-08-01 | 2016-09-27 | Washington University | Multifunctional nanoscopy for imaging cells |
| WO2010021347A1 (en) * | 2008-08-20 | 2010-02-25 | 富士通株式会社 | Material for forming resist-sensitizing film and method for manufacturing semiconductor device |
| US8795951B2 (en) | 2008-08-20 | 2014-08-05 | Fujitsu Limited | Material for forming resist sensitization film and production method of semiconductor device |
| US9111838B2 (en) | 2010-01-08 | 2015-08-18 | Washington University | Method and apparatus for high resolution photon detection based on extraordinary optoconductance (EOC) effects |
Also Published As
| Publication number | Publication date |
|---|---|
| JP2630260B2 (en) | 1997-07-16 |
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