JP3672155B2 - Photosensitive composition and pattern forming method using the same - Google Patents

Description

（ここでＲ１、Ｒ２は同一であっても異なってもよく、水素原子、ハロゲン原子、シアノ基、ニトロ基、シリル基、または１価の有機基を示す。また、Ｒ１、Ｒ２は互いに結合して環状となってもいてもよい。Ｘは＞Ｃ＝Ｏ、または−ＳＯ₂ −を、Ｙは２価の有機基を示す。Ｒ１、Ｒ２、Ｙのうち少なくとも１つは酸により分解する置換基を有する。）
Ｒ１、Ｒ２に用いることのできる１価の有機基としては、例えばメチル、エチル、プロピル、イソプロピル、ブチル、イソブチル、ｔ―ブチル等の置換または非置換のアルキル基；フェニル、トリル、ナフチル、アントリル、ピリジル等の置換または非置換の芳香族基；シクロヘキシル、ピペリジル、ピラニル等の置換または非置換の脂肪族環もしくはヘテロ環基を挙げることができる。
【００３１】
Ｙに用いることのできる２価の有機基としては、例えばエチレン、プロピレン、ブチレン等の置換または非置換の脂肪族基；ベンゼン、ナフタレン、アントラセン、フェナントレン、ピリジン、ピペラジン等の置換または非置換の芳香族環から誘導される基；シクロヘキサン、ピラジン、ピラン、モルホラン等の置換または非置換の脂肪族基もしくはヘテロ環基等を挙げることができる。
【００３２】
酸によって分解する基としては、例えばｔ―ブチルエステル、イソプロピルエステル、エチルエステル、メチルエステル、ベンジルエステル等のエステル類；テトラヒドロピラニルエーテル等のエーテル類；ｔ―ブトキシカルボニル、エトキシカルボニル、メトキシカルボニル等のアルコキシカルボニル類；トリメチルシリルエーテル、トリエチルシリルエーテル、トリフェニルシリルエーテル等のシリルエーテル類が挙げられる。
【００３３】
溶解抑止剤の配合量はアルカリ可溶性樹脂に対し３重量部以上４０重量部以下が好ましく、特に好ましくは１０重量部以上３０重量部以下である。ただし溶解抑止剤の量中にはアルカリ可溶性樹脂中の溶解抑止基を導入した部分を含む。
【００３４】
一方、本発明の感光性組成物をネガ型のレジストとして用いる場合には、溶解抑止剤に代えて架橋剤を用いる。架橋剤としては例えばアミノプラスト樹脂等を用いることができる。具体的には、メラミン−ホロムアルデヒド樹脂、尿素−ホルムアルデヒド樹脂、グリコール−ホルムアルデヒド樹脂等が挙げられる。
【００３５】
架橋剤の配合量はアルカリ可溶性樹脂１００重量部に対し３重量部以上２０重量部以下が好ましい。
次に、本発明の感光性組成物を用いたパターン形成方法について、ポジ型の化学増幅型レジストの場合を例に挙げ図２を用いて説明する。
【００３６】
まず図２（ａ）に示すように、有機溶媒に溶解されたレジストのワニスを回転塗布法やディッピング法などで基板２１上に塗布した後、１５０℃以下好ましくは７０〜１２０℃で乾燥してレジスト膜２２を成膜する。成膜後にプリベーク処理を行なってもよい。なおここでの基板としては、シリコンウェハ、表面に各種の絶縁膜や電極、配線などが形成されたシリコンウェハ、ＳＯＩウェハ、ブランクマスク、ＧａＡｓ、ＡｌＧａＡｓ、ＧａＮなどのＩＩＩ―Ｖ族化合物半導体ウェハ、ＺｎＳｅなどのＩＩ―ＶＩ族化合物半導体ウェハ、クロムまたは酸化クロム蒸着マスク、アルミ蒸着基板、ＩＢＰＳＧコート基板、ＰＳＧコート基板、ＳＯＧコート基板、カーボン膜スパッタ基板などを用いることができる。
【００３７】
次いで、マスクパターン２３を介してレジスト膜２２の所定の領域、すなわち露光部２４に電離放射線２５を照射してレジスト膜２２を露光する。レジスト膜表面に電離放射線２５を直接走査させてレジスト膜２２を露光してもよい。ここで電離放射線としては、紫外線、Ｘ線、低圧水銀ランプ光のｉ線、ｈ線、ｇ線、キセノンランプ光、ＫｒＦやＡｒＦのエキシマレーザー光などのｄｅｅｐＵＶ光やシンクロトロンオービタルラジエーション（ＳＯＲ）、電子線（ＥＢ）、γ線、イオンビームなどを使用することができる。
【００３８】
このとき露光によるエネルギーを高分子鎖全体に存在する色素部分が吸収し、更にその色素部分間においてエネルギー伝達が起こり酸発生部分にエネルギーが集中することによって効率的に酸が発生する。
【００３９】
続いて熱板上やオーブン中での加熱あるいは赤外線照射などにより、レジスト膜２２に１７０℃以下のベーキング処理を施す。これによりレジスト膜２２の露光部２４に発生した酸が溶解抑止剤を触媒的に分解し、露光部２４が選択的にアルカリ可溶化して図２（ｂ）に示すように潜像２６が形成される。
【００４０】
この後、浸漬法、スプレー法などでレジスト膜を現像し、露光部のレジスト膜をアルカリ溶液に溶解することにより除去して、図２（ｃ）に示すような所望のパターン２７を形成する。アルカリ溶液の具体例としては、テトラメチルアンモニウムヒドロキシド水溶液、コリン水溶液などの有機アルカリ水溶液や、水酸化カリウム、水酸化ナトリウムなどの無機アルカリ水溶液、これらにアルコールや界面活性剤などを添加した溶液などが挙げられる。なおここでのアルカリ溶液の濃度は、露光部と未露光部とで溶解速度の差を十分なものとする観点から、１５重量％以下であることが好ましい。
【００４１】
【実施例】
以下、本発明の実施例を説明する。
（実施例１）
溶解抑止能を持つ基を側鎖の一部に導入したポリビニルフェノール樹脂に、高分子鎖の一端にナフトキノンジアジド構造を持ち、高分子鎖の側鎖にカルバゾール二量体を導入した分子量８０００のアクリレート樹脂をナフトキノン換算で５重量部添加した化合物を、シリコンウェハ上にスピンナーを用いて塗布し９０℃で２分間乾燥して、厚さ０．７μｍのレジスト膜を形成した。
【００４２】
続いてこのレジスト膜を加速電圧２０ｋＶで電子線照射して露光を行なった。
次いで露光後のレジスト膜を熱板上で１００℃、２分間の露光後加熱し、この後２．３８重量％濃度のテトラメチルアンモニウムヒドロキシド（ＴＭＡＨ）水溶液による現像処理を行なうことにより、レジストパターンを形成した。このときの感度は１２．５μＣ／ｃｍ² であった。
【００４３】
（実施例２）
溶解抑止能を持つ基を側鎖の一部に導入したポリビニルフェノール樹脂に、高分子鎖の一端にナフトキノンジアジド構造を持ち、高分子鎖の側鎖にカルバゾール二量体を導入した分子量８０００のアクリレート樹脂をナフトキノン換算で５重量部添加した化合物を、シリコンウェハ上にスピンナーを用いて塗布し９０℃で２分間乾燥して、厚さ０．７μｍのレジスト膜を形成した。
【００４４】
続いてこのレジスト膜を波長２４８ｎｍのＫｒＦエキシマレーザー光で露光を行なった。
次いで露光後のレジスト膜を熱板上で１００℃、２分の露光後加熱し、この後２．３８重量％濃度のＴＭＡＨ水溶液による現像処理を行なうことにより、レジストパターンを形成した。このときの感度は４μＣ／ｃｍ² であった。
【００４５】
（比較例１）
溶解抑止能を持つ基を側鎖の一部に導入したポリビニルフェノール樹脂に、低分子量の酸発生剤としてナフトキノンジアジド２０重量部を添加した化合物を、シリコンウェハ上にスピンナーを用いて塗布し９０℃で２分間乾燥して、厚さ０．７μｍのレジスト膜を形成した。
【００４６】
続いてこのレジスト膜を加速電圧２０ｋＶで電子線照射して露光を行なった。
次いで露光後のレジスト膜を熱板上で１００℃、２分間の露光後加熱し、この後２．３８重量％濃度のＴＭＡＨ水溶液による現像処理を行なうことにより、レジストパターンを形成した。このときの感度は２０μＣ／ｃｍ² であった。
【００４７】
【発明の効果】
以上説明したように本発明によれば、感度を向上させることができる感光性組成物およびこれを用いたパターン形成方法を提供することができる。
【図面の簡単な説明】
【図１】 本発明の基本となる概念を説明するための図。
【図２】 本発明によるパターン形成方法を示す製造工程断面図。
【符号の説明】
１１…高分子主鎖
１２…発色基
１３…エネルギー
１４…エネルギー伝達
１５…光反応中心
１６…励起錯体
１７…発光
２１…基板
２２…レジスト膜
２３…マスクパターン
２４…露光部
２５…電離放射線
２６…潜像
２７…パターン[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a photosensitive composition and a pattern forming method using the same.
[0002]
[Prior art]
Various electronic components such as semiconductor integrated circuits require ultra-fine processing, and resists are widely used in the processing technology. With the increase in functionality and density of electronic components, further miniaturization of resist patterns to be formed is required.
[0003]
As an example of a resist used for processing such an ultrafine pattern, it is composed of an alkali-soluble resin, a dissolution inhibitor and an acid generator as disclosed in JP-A-63-27829, and is composed of light, X-rays or high energy. So-called chemically amplified resists have been developed that generate an acid upon irradiation with an electron beam and decompose the dissolution inhibitor by a heat treatment after exposure.
[0004]
[Problems to be solved by the invention]
The conventional chemically amplified resist as described above has the following problems.
First, the exposure amount may be insufficient, that is, the sensitivity may not be sufficient. In particular, when the exposed portion in the pattern has a large area, the exposure amount becomes large, so that the exposure time is increased and the throughput is lowered. Further, when processing ultrafine grooves and ultrafine contact holes, resist is generally not easily removed, and a higher exposure amount is often required than when the exposed portion has a large area.
[0005]
In order to solve these problems, it is necessary to improve the sensitivity of the resist. To that end, it is necessary to increase the amount of the acid generator added in the chemically amplified resist. However, since the acid generator generally has an absorption at the exposure wavelength, increasing the amount of addition causes the transparency of the resist to decrease and the pattern to deteriorate. Some acid generators have low solubility in a developer, and when such an acid generator is used, the acid generator remains as wrinkles during development after exposure. Further, when the acid generator is a low molecular weight compound, the glass transition temperature is lowered and the heat resistance of the resist is lowered. In addition to these, acid generators are generally expensive, and increasing the amount added increases the price of the resist.
[0006]
The present invention has been made to solve the above problems, and an object thereof is to provide a photosensitive composition capable of improving sensitivity and a pattern forming method using the same.
[0007]
[Means for Solving the Problems]
In order to solve the above problems, the present invention provides an alkali-soluble resin, a compound having a substituent that is decomposed or cross-linked by an acid, a molecular weight of 3000 or more, and a polymer main chain and side chains of the polymer main chain. The formed chromophores and photoreactive centers are formed, the energy absorbed by the chromophores by irradiation with ionizing radiation is transmitted to the photoreactive centers by energy transfer between the chromophores, and the transmitted energy The photoreactive center contains an acid generator that generates a reaction that generates an acid .
[0008]
The present invention includes the steps of applying said photosensitive composition onto a substrate, selectively exposing the photosensitive composition, a step of heating the photosensitive composition at a predetermined temperature, the photosensitive And a pattern forming method comprising a step of alkali-developing the composition.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
First, the basic concept of the present invention will be described with reference to the conceptual diagram of FIG.
In FIG. 1, 11 is a polymer main chain of a compound having a molecular weight of 3000 or more (hereinafter referred to as an acid generator) that generates an acid and generates energy transfer by irradiation with ionizing radiation, and 12 is a polymer main chain 11. The chromophoric group formed on the side chain, and 15 is a photoreaction center formed on the side chain of the polymer main chain 11 as in the chromophoric group 12.
[0010]
In the initial photochemical process of the chromophore, the excited state of the chromophore formed by absorbing the energy 13 of ionizing radiation such as light, electron beam, X-ray, etc., releases energy through several processes and returns to the original base normal state. In addition to photophysical processes, there are photochemical processes in which the excited state directly undergoes chemical reactions such as dimerization, isomerization, and hydrogen abstraction. In this photochemical process, the excited chromophore often reacts with surrounding molecules and groups, so it is strongly influenced by the interaction with the surroundings. The rate and yield of such chemical reactions strongly depend on the concentration of molecules and groups involved in the reaction.
[0011]
Also in the polymer system, when energy 13 is absorbed, basically the same reaction as in the initial photochemical process of the low molecular compound occurs, but in the case of the polymer system, the local concentration of the chromophore 12 as a chromophore. Therefore, the interaction between the chromophore groups 12 is likely to occur.
[0012]
The phenomenon in which energy 13 is transferred from the excited chromophore 12 to another chromophore 12 is called energy transfer. In particular, when energy transfer occurs between the chromophores 12 of the same type, energy migration (energy migration) 14 and Call.
[0013]
In order for such energy transfer to occur, a weak interaction between the energy donor and acceptor is required. Energy transfer between the excited singlet state of the energy donor and the ground state of the acceptor is considered to be a mechanism due to dipole-dipole interaction (Forster mechanism). The effective distance of the Forster mechanism ranges from 5 to 10 nm. On the other hand, for energy transfer between the excited triplet state of the energy donor and the ground state of the acceptor, a mechanism that requires electron exchange interaction (Dexter mechanism) is important. The effective distance at this time is 1 to 1.5 nm.
[0014]
Singlet energy transfer in which the overlap between emission and absorption spectra is large, and triplet energy transfer in the case where the triplet energy level of the energy donor is larger than that of the acceptor proceeds on a diffusion-controlled basis. In the polymer system, since the local concentration of the chromophore 12 is high and the same chromophore 12 exists in the vicinity of the excited chromophore 12, the energy transfer between the same chromophores 12, that is, the energy transfer 14, is likely to occur.
[0015]
At this time, the following phenomenon occurs in the polymer system.
The energy 13 of ionizing radiation absorbed by a certain chromophore 12 is transmitted to the adjacent chromophore 12 by energy transmission 14. As a result, energy transfer from the excited chromophore 12 to the adjacent chromophore 12 occurs, and this chromophore 12 also transmits energy 14 to other chromophores 12. Thereby, energy is transmitted in the chain length direction of the polymer chain.
[0016]
However, when the local concentration of the chromophore 12 is high in the polymer system, the chromophore 12 in the excited state can easily form an exciplex 16 with the chromophore 12 in the vicinity. Since the formation of the exciplex 16 serves as a trap site for the energy transfer 14, the energy transfer 14 is interrupted at the portion where the exciplex 16 is formed. This trap site undergoes a reaction such as emission and deactivation of the energy by light emission 17 such as excitation dimer light emission.
[0017]
Therefore, in order to increase the efficiency of the energy transfer 14, it is effective to use the chromophoric group 12 having a shape that hardly forms the exciplex 16 due to a steric hindrance or the like. As such a structure, for example, J.A. Polym. Sci. Polym. Lett. Ed. 19, 11, (1981), such as trans-1,2-di-carbazolylcyclobutane or Macromol. 17, 235 (1984), a structure in which a benzene ring is bonded to the 10th position of anthracene, poly (2- ( 9-carbazolyl) ethyl methacrylate) and the like.
[0018]
When the photoreaction center 15 exists in a part of the polymer chain that generates the energy transfer 14, the 13 energy absorbed by the chromophore 12 in the polymer is collected in the photoreaction center 15 by the energy transfer 14, and the photoreaction center 15. Reacts. As a result, even if the energy 13 of the ionizing radiation is absorbed by any part of the polymer chain, it is possible to use these energies for the photoreaction, thereby obtaining an effect of increasing the quantum yield of the photoreaction.
[0019]
Even if the photoreaction center 15 is not directly excited, energy transfer 14 occurs due to excitation of the chromophoric group 12 in the polymer chain, energy is transferred to the photoreaction center, and the photoreaction center is excited and reacts. Therefore, even with light having a wavelength that cannot directly excite the photoreaction center, or ionizing radiation such as an electron beam or X-ray, the photoreaction center 15 can be excited and reacted. That is, the range of selection of light sources that can be used for fine pattern drawing is widened. In other words, it can be said that the range of structures that can be used for the photoreaction center 15 is widened. In order to apply this to a photosensitive composition as a resist material for fine processing, for example, a group capable of generating an acid from an excited state may be introduced as the photoreaction center 15.
[0020]
The photosensitive composition of the present invention using such energy transfer will be described below.
The photosensitive composition of the present invention is used as a chemically amplified resist. Specifically, an alkali-soluble resin and a compound having a substituent that is decomposed by an acid (hereinafter referred to as a dissolution inhibitor), an acid generator Or an alkali-soluble resin, a compound having a substituent that is crosslinked by an acid (hereinafter referred to as a crosslinking agent), and an acid generator.
[0021]
Of these, the alkali-soluble resin will be described first. As the alkali-soluble resin, a polymer in which a part of the hydroxyl groups of the alkali-soluble resin is protected with a dissolution inhibiting group is used. The resin that can be used is not particularly limited, but in general, a polymer having a phenol skeleton can be used.
[0022]
Specifically, novolak resins such as phenol novolak resin, cresol novolak resin, xylenol novolak resin, naphthol novolak resin; vinylphenol resin (hydroxystyrene resin); isopropenylphenol resin; hydroxystyrene and acrylic acid, methacrylic acid Derivatives, acrylonitrile, copolymers with styrene derivatives, etc .; copolymers of isopropenylphenol with acrylic acid, methacrylic acid derivatives, acrylonitrile, styrene derivatives, etc.
[0023]
More specifically, poly (hydroxystyrene), a copolymer of isopropenylphenol and acrylonitrile, a copolymer of isopropenylphenol and styrene, a copolymer of hydroxystyrene and methylmethacrylate, hydroxystyrene and styrene, Copolymers or the like can be used. Moreover, silicon-containing alkali-soluble resins such as polysiloxane having phenol in the side chain, polysilane having phenol in the side chain, and novolak synthesized from phenol having silicon in the side chain can also be used.
[0024]
Examples of the dissolution inhibiting group introduced into these resins include one or two of t-butoxycarbonyl group, acetic acid t-butoxycarbonyl group, tetrahydropyranyl group, oxohexyl group, trimethylsilyl group, triethylsilyl group and the like. The above is mentioned.
[0025]
Next, the acid generator will be described. The acid generator used in the present invention is characterized in that not only a compound that generates an acid upon exposure to ionizing radiation is used as a polymer, but also energy absorbed by the polymer portion is collected in a photoreaction center by energy transfer. That is, it is characterized in that it has an acid generating portion at the end of the polymer chain, in the middle, or both, and its energy transfer efficiency is high.
[0026]
The molecular weight of the acid generator is at least 3000 or more, more preferably 5000 or more. When it is less than 3000, there are few coloring groups related to energy transmission, and the efficiency of energy transmission becomes low.
[0027]
Various polymer structures that efficiently generate energy transfer are conceivable. For example, a structure in which every other methylene chain has a coloring group is mentioned.
Various chromogenic groups that cause energy transfer are conceivable. For example, a group containing an aromatic ring such as a benzene ring, a naphthalene ring, an anthracene ring, carbazole, or benzophenone can be used.
[0028]
At this time, in consideration of suppressing the inhibition of energy transfer by forming an exciplex, a chromophore that is difficult to form an exciplex by having a structure having steric hindrance is effective. Examples of the structure having steric hindrance include a structure in which two or more aromatic rings are connected, a structure in which a bulky group is introduced, and a structure in which a spacer such as methylene is inserted between the main chain and the side chain. It is done.
[0029]
Examples of the photoreactive center that generates an acid include various reactive atomic groups. For example, a naphthoquinonediazide structure or a sulfonyl structure can be used.
Next, the dissolution inhibitor will be described. When the photosensitive composition of the present invention is used as a positive resist, a dissolution inhibitor is used. As a dissolution inhibitor, it has the ability to inhibit dissolution in an alkali-soluble resin in an unexposed state, while it has a substituent that decomposes in the presence of an acid, and the decomposed product is caused by the action of an alkaline solution. Compounds that produce COO— or —SO ₃ — can be used. An example of such a dissolution inhibitor is a compound represented by the following formula (1).
[0030]
[Chemical 1]

(Here, R1 and R2 may be the same or different and each represents a hydrogen atom, a halogen atom, a cyano group, a nitro group, a silyl group, or a monovalent organic group. Also, R1 and R2 are bonded to each other. X may be> C═O, or —SO ₂ —, Y may be a divalent organic group, and at least one of R1, R2, and Y may be substituted with an acid. Group.)
Examples of monovalent organic groups that can be used for R1 and R2 include substituted or unsubstituted alkyl groups such as methyl, ethyl, propyl, isopropyl, butyl, isobutyl, and t-butyl; phenyl, tolyl, naphthyl, anthryl, Examples thereof include substituted or unsubstituted aromatic groups such as pyridyl; substituted or unsubstituted aliphatic rings or heterocyclic groups such as cyclohexyl, piperidyl, and pyranyl.
[0031]
Examples of the divalent organic group that can be used for Y include substituted or unsubstituted aliphatic groups such as ethylene, propylene, and butylene; substituted or unsubstituted aromatic groups such as benzene, naphthalene, anthracene, phenanthrene, pyridine, and piperazine. A group derived from an aromatic ring; a substituted or unsubstituted aliphatic group or heterocyclic group such as cyclohexane, pyrazine, pyran, morpholane and the like.
[0032]
Examples of the group capable of decomposing by an acid include esters such as t-butyl ester, isopropyl ester, ethyl ester, methyl ester and benzyl ester; ethers such as tetrahydropyranyl ether; t-butoxycarbonyl, ethoxycarbonyl, methoxycarbonyl and the like. Alkoxycarbonyls; silyl ethers such as trimethylsilyl ether, triethylsilyl ether, triphenylsilyl ether and the like.
[0033]
The blending amount of the dissolution inhibitor is preferably from 3 to 40 parts by weight, particularly preferably from 10 to 30 parts by weight, based on the alkali-soluble resin. However, the amount of the dissolution inhibitor includes a portion into which a dissolution inhibitor group has been introduced in the alkali-soluble resin.
[0034]
On the other hand, when the photosensitive composition of the present invention is used as a negative resist, a crosslinking agent is used in place of the dissolution inhibitor. As the crosslinking agent, for example, an aminoplast resin can be used. Specific examples include melamine-holomaldehyde resin, urea-formaldehyde resin, glycol-formaldehyde resin and the like.
[0035]
The blending amount of the crosslinking agent is preferably 3 to 20 parts by weight with respect to 100 parts by weight of the alkali-soluble resin.
Next, a pattern forming method using the photosensitive composition of the present invention will be described with reference to FIG. 2 using a positive chemically amplified resist as an example.
[0036]
First, as shown in FIG. 2A, a resist varnish dissolved in an organic solvent is applied on the substrate 21 by a spin coating method or a dipping method, and then dried at 150 ° C. or less, preferably 70 to 120 ° C. A resist film 22 is formed. A pre-bake treatment may be performed after the film formation. As the substrate here, a silicon wafer, a silicon wafer having various insulating films, electrodes, wirings and the like formed on the surface, an SOI wafer, a blank mask, a III-V group compound semiconductor wafer such as GaAs, AlGaAs, GaN, A II-VI compound semiconductor wafer such as ZnSe, a chromium or chromium oxide deposition mask, an aluminum deposition substrate, an IBPSG coated substrate, a PSG coated substrate, an SOG coated substrate, a carbon film sputtering substrate, or the like can be used.
[0037]
Next, the resist film 22 is exposed by irradiating a predetermined region of the resist film 22 through the mask pattern 23, that is, the exposure unit 24 with the ionizing radiation 25. The resist film 22 may be exposed by scanning the surface of the resist film with ionizing radiation 25 directly. Here, as ionizing radiation, ultraviolet rays, X-rays, i-rays of low-pressure mercury lamp light, h-rays, g-rays, xenon lamp light, deep UV light such as KrF or ArF excimer laser light, synchrotron orbital radiation (SOR), Electron beams (EB), γ rays, ion beams, and the like can be used.
[0038]
At this time, the dye portion existing in the entire polymer chain absorbs the energy from the exposure, and further, energy is transferred between the dye portions, and the energy is concentrated in the acid generating portion, whereby the acid is efficiently generated.
[0039]
Subsequently, the resist film 22 is baked at 170 ° C. or lower by heating on a hot plate or in an oven or by infrared irradiation. As a result, the acid generated at the exposed portion 24 of the resist film 22 catalytically decomposes the dissolution inhibitor, and the exposed portion 24 selectively solubilizes with alkali to form a latent image 26 as shown in FIG. Is done.
[0040]
Thereafter, the resist film is developed by an immersion method, a spray method, and the like, and the resist film in the exposed portion is removed by dissolving in an alkaline solution, thereby forming a desired pattern 27 as shown in FIG. Specific examples of the alkaline solution include an organic alkaline aqueous solution such as tetramethylammonium hydroxide aqueous solution and choline aqueous solution, an inorganic alkaline aqueous solution such as potassium hydroxide and sodium hydroxide, and a solution obtained by adding an alcohol or a surfactant to these. Is mentioned. In addition, it is preferable that the density | concentration of an alkaline solution here is 15 weight% or less from a viewpoint of making the difference of a dissolution rate sufficient between an exposed part and an unexposed part.
[0041]
【Example】
Examples of the present invention will be described below.
(Example 1)
An acrylate having a molecular weight of 8000 having a naphthoquinonediazide structure at one end of the polymer chain and a carbazole dimer introduced into the side chain of the polymer chain into a polyvinylphenol resin having a group having a dissolution inhibiting ability introduced into a part of the side chain. A compound added with 5 parts by weight of resin in terms of naphthoquinone was applied onto a silicon wafer using a spinner and dried at 90 ° C. for 2 minutes to form a resist film having a thickness of 0.7 μm.
[0042]
Subsequently, this resist film was exposed by irradiating it with an electron beam at an acceleration voltage of 20 kV.
Next, the exposed resist film is heated on a hot plate after exposure at 100 ° C. for 2 minutes, and then developed with a 2.38 wt% aqueous solution of tetramethylammonium hydroxide (TMAH) to form a resist pattern. Formed. The sensitivity at this time was 12.5 μC / cm ² .
[0043]
(Example 2)
An acrylate having a molecular weight of 8000 having a naphthoquinonediazide structure at one end of the polymer chain and a carbazole dimer introduced into the side chain of the polymer chain into a polyvinylphenol resin having a group having a dissolution inhibiting ability introduced into a part of the side chain. A compound added with 5 parts by weight of resin in terms of naphthoquinone was applied onto a silicon wafer using a spinner and dried at 90 ° C. for 2 minutes to form a resist film having a thickness of 0.7 μm.
[0044]
Subsequently, this resist film was exposed with KrF excimer laser light having a wavelength of 248 nm.
Next, the exposed resist film was heated after exposure at 100 ° C. for 2 minutes on a hot plate, and then developed with a 2.38 wt% TMAH aqueous solution to form a resist pattern. The sensitivity at this time was 4 μC / cm ² .
[0045]
(Comparative Example 1)
A compound obtained by adding 20 parts by weight of naphthoquinonediazide as a low molecular weight acid generator to a polyvinylphenol resin in which a group having a dissolution inhibiting ability is introduced into a part of the side chain is applied onto a silicon wafer using a spinner and applied at 90 ° C. And dried for 2 minutes to form a resist film having a thickness of 0.7 μm.
[0046]
Subsequently, this resist film was exposed by irradiating it with an electron beam at an acceleration voltage of 20 kV.
Next, the exposed resist film was heated after exposure at 100 ° C. for 2 minutes on a hot plate, and then developed with a 2.38 wt% TMAH aqueous solution to form a resist pattern. The sensitivity at this time was 20 μC / cm ² .
[0047]
【The invention's effect】
As described above, according to the present invention, a photosensitive composition capable of improving sensitivity and a pattern forming method using the same can be provided.
[Brief description of the drawings]
FIG. 1 is a diagram for explaining a basic concept of the present invention.
FIG. 2 is a manufacturing process cross-sectional view illustrating a pattern forming method according to the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 11 ... Polymer main chain 12 ... Color development group 13 ... Energy 14 ... Energy transfer 15 ... Photoreaction center 16 ... Excitation complex 17 ... Light emission 21 ... Substrate 22 ... Resist film 23 ... Mask pattern 24 ... Exposure part 25 ... Ionizing radiation 26 ... Latent image 27 ... pattern

Claims (6)

An alkali-soluble resin;
A compound having a substituent that is decomposed or cross-linked by an acid;
Energy having a molecular weight of 3000 or more, having a plurality of chromophores and photoreactive centers formed on a polymer main chain and side chains of the polymer main chain, and absorbed by the chromophore upon irradiation with ionizing radiation To the photoreactive center by energy transfer between the chromophores, and an acid generator that causes the photoreactive center to generate an acid by the transmitted energy,
A photosensitive composition comprising:   The coloring group is at least selected from a benzene ring, a naphthalene ring, an anthracene ring, carbazole, and benzophenone. 1 The photosensitive composition according to claim 1, which is a seed.   The photosensitive composition according to claim 1, wherein the photoreactive center has at least one structure selected from a naphthoquinonediazide structure and a sulfonyl structure.   2. The photosensitive composition according to claim 1, wherein the acid generator is an acrylate resin having a naphthoquinone diazide structure at one end of a polymer main chain and a carbazole dimer introduced into a side chain of the polymer. .   2. The photosensitive resin according to claim 1, wherein the acid generator is an acrylate resin having a molecular weight of 8000, having a naphthoquinone diazide structure at one end of a polymer main chain, and a carbazole dimer introduced into a side chain of the polymer. Sex composition.   Applying a photosensitive composition according to claim 1, 2, 3, 4, or 5 on a substrate;
Selectively exposing the photosensitive composition;
Heating the photosensitive composition at a predetermined temperature;
A step of alkali developing the photosensitive composition;
A pattern forming method comprising:

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