JP3587981B2 - Photosensitive resin composition - Google Patents

Description

【００１４】
（但しＲ_３ 、Ｒ_４ はそれぞれ独立して一価の炭化水素基を示し、ｎは０又は１以上の整数を示す）で表されるテトラカルボン酸二無水物等の芳香族テトラカルボン酸二無水物やこれら芳香族テトラカルボン酸の水素添加無水物、及び下記一般式（３）〜（４）で表される化合物等の脂環式テトラカルボン酸二無水物等
【００１５】
【化３】

【００１６】
【化４】

【００１７】
を例示することができる。またこれらのテトラカルボン酸二無水物の他に耐熱性及び機械特性を低下させぬ程度に脂肪族テトラカルボン酸二無水物を用いてもよい。これらのテトラカルボン酸二無水物は、その一種のみを用いてもよく、また二種以上を併用しても差し支えない。
【００１８】
本発明のポリイミド樹脂の製造方法の一例を示すと、有機溶媒中、ジアミン化合物とテトラカルボン酸二無水物とを−２０〜５０℃で数分間から数日間反応させることにより、ポリイミド前駆体であるポリアミド酸を得ることができる。
【００１９】
ポリアミド酸の合成反応に使用できる有機溶媒としては、Ｎ，Ｎ −ジメチルアセトアミド、Ｎ −メチル−２ −ピロリドン等のアミド系溶媒、ベンゼン、アニソール、ジフェニルエーテル、ニトロベンゼン、ベンゾニトリル、ピリジンのような芳香族系溶媒、クロロホルム、ジクロロメタン、１，２−ジクロロエタン、１ ，１ ，２ ，２ 一テトラクロロエタンのようなハロゲン系溶媒、テトラヒドロフラン、ジオキサン、ジグリムのようなエーテル系溶媒等を例示することができる．特にＮ ，Ｎ −ジメチルアセトアミドや、Ｎ −メチル−２ −ピロリドン等のアミド系溶媒を使用すると、高重合体のポリアミド酸を得ることができる．
【００２０】
上記のようにして得られたポリアミック酸は次いで加熱もしくは無水酢酸とピリジンによる脱水閉環剤による処理などの公知の方法によりポリイミド樹脂とする。脱水閉環方法の一例を挙げると、例えばトルエン、キシレン等の還流による熱環化法等を使用することができる。このポリイミド樹脂は、脱水する際に用いたトルエン、キシレン等を含んでいるため、水、メタノール等の貧溶媒へポリイミド樹脂溶液を投入、再沈殿を行い、更にこれを乾燥しポリイミド樹脂の粉末とする。これを所望の有機溶媒へ溶解させ、本発明に使用するポリイミド樹脂の溶液とする。
【００２１】
この方法において本発明のポリイミド樹脂の分子量はジアミン化合物との仕込量によって制限され、等モル量使用したときに高分子量のポリイミド樹脂を製造することができる。
【００２２】
本発明において、上述したポリイミド樹脂（Ａ）と組み合わせて使用される光分解性酸発生剤（Ｂ）としては、アリルジアゾニウム塩（ＡｒＮ_２ ^＋ Ｘ⁻ ）、ジアリルヨードニウム塩（Ａｒ_２ Ｉ^＋ Ｘ⁻ ）、トリアリルスルホニル塩（Ａｒ_３ Ｓ^＋ Ｘ⁻ ）、芳香族スルホン酸エステル、更に鉄アレーン錯体等を例示することができる。これらの光分解性酸発生剤は、その一種のみを用いてもよく、また二種以上を併用しても差し支えない。また必要に応じて増感剤を用いることができる。これらの光分解性酸発生剤は活性光線の照射によって酸を発生し、光分解性酸発生剤から生じた酸は一般式（１）の−Ｏ−Ｒ_１ −Ｏ−の分解反応の触媒として作用する。増感剤としてはペリレン、ピレン、アントラセン、チオキサントン、ミヒラーケトン、ベンソフェノン、９−フルオレノン、アンスロン等を例示することができる。
【００２３】
本発明の感光性樹脂組成物は前述した一般式（１）に示されるポリイミド樹脂（Ａ）と光分解性酸発生剤（Ｂ）とを混合することによって得られる。両者の配合比率は任意であるが、良好な感光性と保存安定性を得るためには、ポリイミド樹脂（Ａ）１００重量部に対して光分解性酸発生剤を０．１〜５０重量部の量で使用することが好適であり、更に好ましくは０．５〜３０重量部で使用することが望ましい。ポリイミド樹脂（Ａ）１００重量部に対して光分解性酸発生剤が０．１重量部以下だと良好な感光性が得られず、また５０重量部以上だと耐熱性、保存安定性に問題がある。
【００２４】
本発明の感光性樹脂組成物は一般的には適当な有機溶剤に溶解した形で使用され、基材に塗布される。ここで用いられる溶剤としては、 Ｎ−メチル−２ −ピロリドン、Ｎ，Ｎ −ジメチルアセトアミド、γ−ブチロラクトン、ジメチルスルホキシド、ジエチレングリコールジメチルエーテル、ジエチレングリコールジエチルエーテル、ジエチレングリコールジブチルエーテル、ジエチレングリコールモノメチルエーテル、プロピレングリコールモノメチルエーテルアセテート等を例示することができる。これらの溶剤はその一種のみを用いてもよくまた二種以上を併用しても差し支えない。
【００２５】
本発明の感光性樹脂組成物の使用方法は、まず該組成物を適当な支持体、例えばシリコンウエハーやセラミック、アルミ基板等に塗布する。塗布方法は、スピンナーを用いた回転塗布、スプレーコーターを用いた噴霧塗布、浸漬、印刷、ロールコーティング等を行う。次に、６０〜１２０ ℃でプリベークをして塗膜を乾燥後、所望のパターン形状に活性光線を照射する。活性光線としては、水銀灯、キセノンランプ、メタルハライドランプ、ケミカルランプ、カーボンアーク灯、ｇ線、ｉ線、ｄｅｅｐ−ＵＶ 光、さらにはヘリウムネオンレーザー、アルゴンイオンレーザー、クリプトンイオンレーザー、ヘリウム・カドミウムイオンレーザー、ＫｒＦエキシマレーザーなどの高密度エネルギービーム等を例示することができる。
活性光線の照射後、一般式（１）の主鎖中の−Ｏ−Ｒ_１ −Ｏ−をフェノール性水酸基に分解する反応を促進するために、６０〜１６０℃の範囲で０．５〜３０分間加熱することが好ましい。
【００２６】
次に照射部を現像液で溶解除去することによりレリーフパターンを得る。現像液としては、水酸化ナトリウム、水酸化カリウム、炭酸ナトリウム、ケイ酸ナトリウム、メタケイ酸ナトリウム、アンモニア水等の無機アルカリ類、エチルアミン、ｎ−プロピルアミン等の第一アミン類、ジエチルアミン、ジ−ｎ−プロピルアミン等の第二アミン類、トリエチルアミン、メチルジエチルアミン等の第三アミン類、ジメチルエタノールアミン、トリエタノールアミン等のアルコールアミン類、テトラメチルアンモニウムヒドロキシド、テトラエチルアンモニウムヒドロキシド等の第四級アンモニウム塩等のアルカリ類の水溶液、及びこれにメタノール、エタノールのごときアルコール類等の水溶性有機溶媒や界面活性剤を適当量添加した水溶液を好適に使用することができる。現像方法としては、スプレー、パドル、侵漬、超音波等の方式が可能である。次に現像によって形成したレリーフパターンをリンスする。リンス液としては蒸留水を使用する。
【００２７】
また本発明の感光性樹脂組成物は酸により主鎖を分解する方式をとるため現像液として有機溶媒を使用することもできる。有機溶媒としてはＮ −メチル−２ −ピロリドン、Ｎ，Ｎ −ジメチルアセトアミド、γ−ブチロラクトン、ジメチルスルホキシド、ジエチレングリコールジメチルエーテル、ジエチレングリコールジエチルエーテル、ジエチレングリコールジブチルエーテル、ジエチレングリコールモノメチルエーテル、プロピレングリコールモノメチルエーテルアセテート等を例示することができる。これらの溶媒はその一種のみを用いてもよくまた二種以上を併用しても差し支えない。またこれらの有機溶媒にメタノール、エタノール、イソプロパノール等のアルコール類、トルエン、キシレン等の芳香族炭化水素化合物、アセトン、メチルエチルケトン、メチルイソブチルケトン等のケトン類、酢酸エチル、プロピオン酸メチル等のエステル類、テトラヒドロフラン、ジオキサン等のエーテル等の一般溶媒及び水を混合してもよい。
【００２８】
次に加熱処理を行い、耐熱性に富む最終パターンを得る。本発明による感光性樹脂組成物は、半導体用途のみならず、多層回路の層間絶縁膜、フレキシブル銅張板のカバーコート、ソルダーレジスト膜及び液晶配向膜としても有用である。
【００２９】
【実施例】
以下、本発明を実施例によりさらに詳細に説明する。
［実施例１］
ポリイミド（Ａ ）の合成
ビス（４−アミノフェノキシ）メタン４．０４０ｇ（０．０２０ｍｏｌ）を５０ｍＬのＮ −メチル−２―ピロリドンに溶解し、これに８．８８０ｇ（０．０２０ｍｏｌ）の２ ，２ −ビス（３， ４−ジカルボキシフェニル）ヘキサフルオロプロパン二無水物を固体のまま一度に加えた。２５℃で１２時間攪拌を行い、ポリアミック酸溶液を調整した。このポリアミック酸溶液に無水酢酸４．０８ｇとピリジン３．１６ｇを加え、１０時間攪拌を行いイミド化を行った。この反応溶液を大量の水とメタノールの混合溶液に投入してポリイミド樹脂を再沈殿し、更にこれを１２時間真空乾燥しポリイミド樹脂粉末を得た。
【００３０】
感光性樹脂組成物の作成
合成したポリイミド１６重量部、下記一般式（５）で表される光分解性酸発生剤４重量部をＮ−メチル−２―ピロリドン８０重量部に溶解し、０．２ミクロンのテフロンフィルターで濾過し、感光性ワニスを得た。
【００３１】
【化５】

【００３２】
特性評価
この感光性ワニスをスピンコーターを用いてシリコンウエハーに約５ミクロン厚さに塗布して乾燥した後、フォトマスクを通して、超高圧水銀灯にガラスフィルターをかけた４３６ｎｍの波長の活性光線を照射し、２００ｍＪ／ｃｍ ^２ の密着露光を行い、更に１２０℃で１０分間加熱を行った。次いで２．５％水酸化テトラメチルアンモニウム水溶液で現像を行い、更に純水でリンスを行い、得られたライン・アンド・スペースのパターン形状、及び得られた最小の線幅を観測した。また、それらを２００℃で１時間加熱処理を行い、硬化前の膜厚に対する残膜率を求めた。結果を表１に示す。
【００３３】
［実施例２］
ビス（４−アミノフェノキシ）メタンの代わりに２、２−ビス（４−アミノフェノキシ）プロパンを用いた以外は、実施例１と同様にして合成、パターン形成を行い、特性評価を行った。結果を表１に示す。
【００３４】
［実施例３］
ビス（４−アミノフェノキシ）メタンの代わりに２、２−ビス（４−アミノフェノキシ）ヘキサフルオロプロパンを用いた以外は、実施例１と同様にして合成、パターン形成を行い、特性評価を行った。結果を表１に示す。
【００３５】
［実施例４］
ビス（４−アミノフェノキシ）メタンの代わりに２、２−ビス（４−アミノフェノキシ）ヘキサフルオロプロパン、また２ ，２ −ビス（３， ４−ジカルボキシフェニル）ヘキサフルオロプロパン二無水物の代わりに２ ，２ −ビス［ ４−（ ３， ４−ジカルボキシフェノキシ）フェニル］ プロパン二無水物を用いた以外は、実施例１と同様にして合成、パターン形成を行い、特性評価を行った。結果を表１に示す。
【００３６】
【表１】

【００３７】
以上の結果より、本発明は、感光性、解像性に優れたものであり、高温による加熱を必要としなく、残膜性も優れた、また作業上安全なアルカリ水溶液に現像が可能な感光性樹脂組成物を提供できることが判明した。
【００３８】
【発明の効果】
本発明の感光性樹脂組成物は、従来のものでは達成できなかった感光性、解像性、残膜性に優れ、かつ高温による加熱を必要としなく、また作業上安全なアルカリ水溶液に現像が可能な感光性樹脂組成物である。この感光性樹脂組成物を加熱して得られるポリイミド皮膜は、電子部品用保護膜として好適に使用することができるため、工業材料としての価値が大きい。[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a novel polyimide resin effectively used for applications such as a protective film for a semiconductor element, an alignment film for a liquid crystal display element, and an interlayer insulating film for a multilayer printed wiring board, and a photosensitive resin composition containing the same. About.
[0002]
[Prior art]
Conventionally, a polyimide resin having excellent heat resistance and excellent electrical and mechanical properties has been used for a surface protective film and an interlayer insulating film of a semiconductor element. There is a demand for remarkable improvements in heat cycle resistance and heat shock resistance due to the shift to surface mounting due to the thinning and miniaturization of resin stopper packages and solder reflow. Have been.
[0003]
On the other hand, in recent years, a technique of a so-called photosensitive polyimide in which a polyimide itself is provided with photosensitivity, which can simplify a part of a pattern forming process and can shorten the process, has attracted attention. For example, JP-A-49-115541 and JP-A-55-45746 disclose a material comprising a polyimide precursor having a photosensitive group introduced into a carboxyl group of a polyamic acid through an ester bond. Japanese Patent No. 100143 proposes a material comprising a photosensitive group introduced into a carboxyl group of a polyamic acid by an amide bond, and the like. Requires a solvent such as N-methyl-2-pyrrolidone, which is problematic in terms of safety and pollution. Therefore, in recent years, a positive photosensitive resin that can be developed with an alkaline aqueous solution has been developed. For example, a photosensitive resin composition comprising an esterified polyamic acid polymer and a photosensitive quinonediazide according to JP-A-2-181149 has been proposed. This photosensitive resin composition uses an aqueous alkaline solution to remove the via holes, and therefore does not require an organic solvent as in the case of a conventional photosensitive polyimide resin, so that the safety during operation is further improved.
[0004]
However, all of the above-mentioned conventional photosensitive polyimide resins are obtained by imparting photosensitivity to a polyamic acid which is a precursor of the polyimide resin. In order to finally convert (imidize) the polyamic acid to the polyimide resin, 300 Heat treatment (dehydration ring closure) must be performed at a high temperature of ℃ or more, and it can be used only on a substrate or element that can withstand this heat. Also, the pattern obtained at the time of imidization causes volume shrinkage due to heat. Dimensional changes such as are large and there is a problem in dimensional stability.
[0005]
[Problems to be solved by the invention]
The present invention has been made to solve the above-mentioned problems of the conventional photosensitive polyimide. That is, an object of the present invention is to provide a novel photosensitive resin characterized in that the film does not swell during development, can be developed with an alkaline aqueous solution that is safe for operation, and does not require heat treatment at high temperatures. It is to provide a composition.
[0006]
[Means for Solving the Problems]
As a result of intensive studies, the present inventors were able to solve the above-mentioned problems of the prior art. That is, the present invention comprises, in claim 1, at least a novel polyimide resin having an acetal structure capable of being decomposed in the presence of an acid in a main chain thereof, and a photodecomposable acid generator (B). And a photosensitive resin composition characterized by the following.
[0007]
Further, in the above-mentioned general formula (2), the presence of an acid cleaves -OR ₁ -O-, which is an acetal site in the main chain of the general formula (1), to produce a phenolic hydroxyl group. A photosensitive resin composition comprising at least a novel polyimide resin having a repeating unit represented by the formula (I) and a photodecomposable acid generator (B) .
[0009]
By using a photosensitive resin composition containing a polyimide resin characterized by the above, there is no swelling of the film at the time of development, it is possible to develop with an alkaline aqueous solution that is safe for work, and heat treatment at high temperature An object of the present invention is to provide a novel photosensitive resin composition which is not required.
[0010]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, the polyimide resin of the present invention, which explains the present invention in more detail, is represented by the general formula (1), and can be easily produced from, for example, a diamine compound and a tetracarboxylic dianhydride.
[0011]
Examples of the diamine compound include bis (4-aminophenoxy) methane, bis (4-aminophenoxy) ethane, 1,3-bis (4-aminophenoxy) propane, and 2,2-bis (4-aminophenoxy) propane 2,2-bis (4-aminophenoxy) hexafluoropropane, bis (3-aminophenoxy) methane, bis (3-aminophenoxy) ethane, 1,3-bis (3-aminophenoxy) propane, 2,2 Examples thereof include diamine compounds such as -bis (3-aminophenoxy) propane and 2,2-bis (3-aminophenoxy) hexafluoropropane. These diamine compounds may be used alone or in combination of two or more.
[0012]
Examples of the tetracarboxylic dianhydride represented by the general formula (1) include pyromellitic dianhydride, 3,4,3 ′, 4′-biphenyltetracarboxylic dianhydride, 3,4,3 ′, 4′-diphenylethertetracarboxylic dianhydride, 3,4,3 ′, 4′-benzophenonetetracarboxylic dianhydride, 3,4,3 ′, 4′-diphenylsulfonetetracarboxylic dianhydride, 2, 2-bis (2,3-dicarboxyphenyl) hexafluoropropane dianhydride, 2,2-bis (3,4-dicarboxyphenyl) hexafluoropropane dianhydride, 3,4,3 ", 4"- Terphenyltetracarboxylic dianhydride, 1,2,5,6-naphthalenetetracarboxylic dianhydride, 2,3,6,7-naphthalenetetracarboxylic dianhydride, 2,3,5,6 Pyridinetetracarboxylic dianhydride, 1,4,5,8-naphthalenetetracarboxylic dianhydride, 3,4,9,10-perylenetetracarboxylic dianhydride, 2,2-bis (3,4- Dicarboxyphenyl) propane dianhydride, 2,2-bis (2,3-dicarboxyphenyl) propane dianhydride, 2,2-bis [4- (2,3-dicarboxyphenoxy) phenyl] propane dianhydride 2,2,2-bis [4- (3,4-dicarboxyphenoxy) phenyl] propane dianhydride, 2,2-bis [4- (2,3-dicarboxyphenoxy) phenyl] hexafluoropropane dianhydride 2,2-bis [4- (3,4-dicarboxyphenoxy) phenyl] hexafluoropropane dianhydride, the following general formula (2)
[0013]
Embedded image

[0014]
(However, R ₃ and R ₄ each independently represent a monovalent hydrocarbon group, and n represents 0 or an integer of 1 or more), such as tetracarboxylic dianhydride. Anhydrides, hydrogenated anhydrides of these aromatic tetracarboxylic acids, and alicyclic tetracarboxylic dianhydrides such as compounds represented by the following general formulas (3) to (4):
Embedded image

[0016]
Embedded image

[0017]
Can be exemplified. In addition to these tetracarboxylic dianhydrides, aliphatic tetracarboxylic dianhydrides may be used to such an extent that heat resistance and mechanical properties are not reduced. These tetracarboxylic dianhydrides may be used alone or in combination of two or more.
[0018]
When an example of the method for producing the polyimide resin of the present invention is shown, in an organic solvent, a diamine compound and a tetracarboxylic dianhydride are reacted at −20 to 50 ° C. for several minutes to several days to obtain a polyimide precursor. Polyamic acid can be obtained.
[0019]
Examples of the organic solvent that can be used for the polyamic acid synthesis reaction include amide solvents such as N, N-dimethylacetamide and N-methyl-2-pyrrolidone, and aromatic solvents such as benzene, anisole, diphenyl ether, nitrobenzene, benzonitrile and pyridine. Examples thereof include system solvents, halogen-based solvents such as chloroform, dichloromethane, 1,2-dichloroethane, 1,1,2,2,1-tetrachloroethane, and ether-based solvents such as tetrahydrofuran, dioxane, and diglyme. In particular, when an amide-based solvent such as N, N-dimethylacetamide or N-methyl-2-pyrrolidone is used, a high-polymer polyamic acid can be obtained.
[0020]
The polyamic acid obtained as described above is then converted to a polyimide resin by a known method such as heating or treatment with acetic anhydride and pyridine with a dehydrating ring-closing agent. As an example of the dehydration ring closure method, for example, a thermal cyclization method by refluxing toluene, xylene or the like can be used. Since this polyimide resin contains toluene, xylene, etc. used for dehydration, water, the polyimide resin solution is poured into a poor solvent such as methanol, reprecipitated, and further dried to obtain a polyimide resin powder. I do. This is dissolved in a desired organic solvent to obtain a polyimide resin solution used in the present invention.
[0021]
In this method, the molecular weight of the polyimide resin of the present invention is limited by the amount charged with the diamine compound, and when used in equimolar amounts, a high molecular weight polyimide resin can be produced.
[0022]
In the present invention, the photodecomposable acid generator (B) used in combination with the above-mentioned polyimide resin (A) includes an allyldiazonium salt (ArN ₂ ⁺ X ⁻ ) and a diallyliodonium salt (Ar ₂ I ⁺ X ^−). ), Triallylsulfonyl salts (Ar ₃ S ⁺ X ⁻ ), aromatic sulfonic acid esters, and iron arene complexes. These photodecomposable acid generators may be used alone or in combination of two or more. A sensitizer can be used if necessary. These photodecomposable acid generators generate an acid upon irradiation with actinic rays, and the acid generated from the photodecomposable acid generator serves as a catalyst for the decomposition reaction of —O—R ₁ —O— of the general formula (1). Works. Examples of the sensitizer include perylene, pyrene, anthracene, thioxanthone, Michler's ketone, bensophenone, 9-fluorenone, and anthrone.
[0023]
The photosensitive resin composition of the present invention can be obtained by mixing the polyimide resin (A) represented by the aforementioned general formula (1) and the photodecomposable acid generator (B). The mixing ratio of the two is arbitrary, but in order to obtain good photosensitivity and storage stability, 0.1 to 50 parts by weight of the photodecomposable acid generator is added to 100 parts by weight of the polyimide resin (A). It is preferable to use it in an amount, more preferably 0.5 to 30 parts by weight. If the amount of the photo-decomposable acid generator is less than 0.1 part by weight with respect to 100 parts by weight of the polyimide resin (A), good photosensitivity cannot be obtained. There is.
[0024]
The photosensitive resin composition of the present invention is generally used in a form dissolved in an appropriate organic solvent, and is applied to a substrate. Examples of the solvent used herein include N-methyl-2-pyrrolidone, N, N-dimethylacetamide, γ-butyrolactone, dimethyl sulfoxide, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol dibutyl ether, diethylene glycol monomethyl ether, and propylene glycol monomethyl ether acetate. And the like. These solvents may be used alone or in combination of two or more.
[0025]
In the method of using the photosensitive resin composition of the present invention, the composition is first applied to a suitable support, for example, a silicon wafer, ceramic, or aluminum substrate. The coating method includes spin coating using a spinner, spray coating using a spray coater, dipping, printing, roll coating, and the like. Next, after pre-baking at 60 to 120 ° C. and drying the coating film, a desired pattern shape is irradiated with actinic rays. Actinic rays include mercury lamps, xenon lamps, metal halide lamps, chemical lamps, carbon arc lamps, g-rays, i-rays, deep-UV light, helium neon lasers, argon ion lasers, krypton ion lasers, helium cadmium ion lasers And a high-density energy beam such as a KrF excimer laser.
After irradiation with actinic rays, 0.5 to 30 ° C. in the range of 60 to 160 ° C. in order to promote the reaction of decomposing —O—R ₁ —O— in the main chain of the general formula (1) into phenolic hydroxyl groups. It is preferred to heat for minutes.
[0026]
Next, a relief pattern is obtained by dissolving and removing the irradiated portion with a developing solution. Examples of the developer include inorganic alkalis such as sodium hydroxide, potassium hydroxide, sodium carbonate, sodium silicate, sodium metasilicate, and aqueous ammonia, primary amines such as ethylamine and n-propylamine, diethylamine, and di-n. Secondary amines such as propylamine, tertiary amines such as triethylamine and methyldiethylamine, alcoholamines such as dimethylethanolamine and triethanolamine, and quaternary ammoniums such as tetramethylammonium hydroxide and tetraethylammonium hydroxide. An aqueous solution of an alkali such as a salt and an aqueous solution obtained by adding an appropriate amount of a water-soluble organic solvent such as an alcohol such as methanol and ethanol or a surfactant thereto can be suitably used. As a developing method, a method such as spraying, paddle, immersion, and ultrasonic wave can be used. Next, the relief pattern formed by development is rinsed. Distilled water is used as the rinsing liquid.
[0027]
Further, since the photosensitive resin composition of the present invention employs a method in which a main chain is decomposed by an acid, an organic solvent can be used as a developer. Examples of the organic solvent include N-methyl-2-pyrrolidone, N, N-dimethylacetamide, γ-butyrolactone, dimethyl sulfoxide, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol dibutyl ether, diethylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, and the like. be able to. These solvents may be used alone or in combination of two or more. In addition, methanol, ethanol, alcohols such as isopropanol, aromatic hydrocarbon compounds such as toluene and xylene, ketones such as acetone, methyl ethyl ketone and methyl isobutyl ketone, ethyl acetate and esters such as methyl propionate in these organic solvents. General solvents such as ethers such as tetrahydrofuran and dioxane and water may be mixed.
[0028]
Next, heat treatment is performed to obtain a final pattern having high heat resistance. The photosensitive resin composition according to the present invention is useful not only for semiconductor applications, but also as an interlayer insulating film of a multilayer circuit, a cover coat of a flexible copper clad board, a solder resist film, and a liquid crystal alignment film.
[0029]
【Example】
Hereinafter, the present invention will be described in more detail with reference to Examples.
[Example 1]
Synthesis of Polyimide (A) 4.040 g (0.020 mol) of bis (4-aminophenoxy) methane was dissolved in 50 mL of N-methyl-2-pyrrolidone, and 8.880 g (0.020 mol) of 2,2 was added thereto. -Bis (3,4-dicarboxyphenyl) hexafluoropropane dianhydride was added all at once as a solid. Stirring was performed at 25 ° C. for 12 hours to prepare a polyamic acid solution. 4.08 g of acetic anhydride and 3.16 g of pyridine were added to the polyamic acid solution, and the mixture was stirred for 10 hours to perform imidization. The reaction solution was poured into a large amount of a mixed solution of water and methanol to reprecipitate a polyimide resin, and further dried in vacuum for 12 hours to obtain a polyimide resin powder.
[0030]
A photosensitive resin composition was prepared and dissolved 16 parts by weight of polyimide and 4 parts by weight of a photo-decomposable acid generator represented by the following general formula (5) in 80 parts by weight of N-methyl-2-pyrrolidone. The mixture was filtered through a 2 micron Teflon filter to obtain a photosensitive varnish.
[0031]
Embedded image

[0032]
Characteristic evaluation This photosensitive varnish was applied to a silicon wafer to a thickness of about 5 μm using a spin coater, dried, and then irradiated with an actinic ray having a wavelength of 436 nm, which was filtered with a glass filter through an ultra-high pressure mercury lamp through a photomask. , 200 mJ / cm ² , and heating at 120 ° C. for 10 minutes. Subsequently, development was carried out with a 2.5% aqueous solution of tetramethylammonium hydroxide, followed by rinsing with pure water, and the obtained line-and-space pattern shape and the obtained minimum line width were observed. Further, they were subjected to a heat treatment at 200 ° C. for 1 hour, and the residual film ratio to the film thickness before curing was determined. Table 1 shows the results.
[0033]
[Example 2]
Synthesis and pattern formation were performed in the same manner as in Example 1 except that 2,2-bis (4-aminophenoxy) propane was used instead of bis (4-aminophenoxy) methane, and the characteristics were evaluated. Table 1 shows the results.
[0034]
[Example 3]
Synthesis and pattern formation were performed in the same manner as in Example 1 except that 2,2-bis (4-aminophenoxy) hexafluoropropane was used instead of bis (4-aminophenoxy) methane, and the characteristics were evaluated. . Table 1 shows the results.
[0035]
[Example 4]
2,2-bis (4-aminophenoxy) hexafluoropropane instead of bis (4-aminophenoxy) methane, and 2,2-bis (3,4-dicarboxyphenyl) hexafluoropropane dianhydride instead of 2,2-bis (4-aminophenoxy) hexafluoropropane Synthesis and pattern formation were performed in the same manner as in Example 1 except that 2,2-bis [4- (3,4-dicarboxyphenoxy) phenyl] propane dianhydride was used, and the characteristics were evaluated. Table 1 shows the results.
[0036]
[Table 1]

[0037]
From the above results, the present invention is excellent in photosensitivity and resolution, does not require heating at a high temperature, has excellent residual film properties, and can be developed in an alkaline aqueous solution which is safe for operation. It has been found that a conductive resin composition can be provided.
[0038]
【The invention's effect】
The photosensitive resin composition of the present invention has excellent photosensitivity, resolution, and residual film properties that could not be achieved by conventional methods, does not require heating at a high temperature, and can be developed in an alkaline aqueous solution that is safe for operation. It is a possible photosensitive resin composition. The polyimide film obtained by heating the photosensitive resin composition can be suitably used as a protective film for electronic parts, and therefore has great value as an industrial material.

Claims (2)

A photosensitive resin composition comprising at least a polyimide resin (A) having an acetal structure in its main chain and a photodecomposable acid generator (B). The photosensitive material according to claim 1, wherein the acetal structure contains at least a polyimide resin (A) having a repeating unit represented by the following general formula (1) and a photodegradable acid generator (B). Resin composition.

(Where Ar is a tetravalent organic residue, R ₁ is an alkylene group or a perfluoroalkylene group, R ₂ is a hydrogen atom, an alkyl group, a perfluoroalkyl group, or a halogen atom, and n is an integer of 1 to 4. Show)