JPH0572736A - Production of fluorine-contained polyimide resin film pattern - Google Patents

Abstract

PURPOSE:To provide the process for production of patterns which do not crack by simultaneously executing the development of a photosensitive resin film and the etching of a low dielectric constant material film. CONSTITUTION:A polyamide acid soln. which is expressed by formula I and is obtd. by bringing tetrabasic dianhydride and diamine into reaction in an org. solvent is applied on a substrate 1 and is heat treated in a 160 to 200 deg.C range to form a fluorine-contained polyimide resin film 4. After the photosensitive polyimide resin film 5 is formed on this film 4, the film is exposed via a photomask and thereafter, the development processing of the photosensitive polyimide resin film 5 and the etching of the fluorine-contained polyimide resin film 4 are simultaneously executed. In the formula I, R<2> denotes a quadrivalent org. group; R<2> denotes a bivalent org. group; R denotes H or <=4C alkyl group; (n) denotes integer >=1; at least either of R<1> and R<2> have F.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a fluorine-containing polyimide resin film pattern, and more particularly to a method for producing a fluorine-containing polyimide resin film pattern suitable for a surface protective film and an interlayer insulating film for semiconductor elements and the like.

[0002]

2. Description of the Related Art Conventionally, a polyimide resin has been used as a surface protective film or an interlayer insulating film for various electronic parts such as semiconductors. This polyimide resin is made of PSG, SiO ₂ , Si
For example, a flat film can be formed on a substrate having larger irregularities than an inorganic insulating film such as N, a thick film of 1 μm or more can be easily formed, and heat resistance is high compared to other organic materials. Because of its advantages, it has been adopted as an interlayer insulating film for bipolar ICs, and has recently been widely used as an α-ray shielding film and a buffer coat film for memory devices.

In applying a polyimide resin film to these uses, it is necessary to form a pattern such as a through hole in a polyimide resin film formed on a wafer which is a semiconductor substrate by a spinning method or the like. It is formed by a wet etching process using a photoresist. As a pattern formation method,
(1) A method of forming a negative resist pattern as a mask material on a polyimide resin film heat-treated at 220 to 350 ° C. and then patterning with a hydrazine-based solution,
(2) A method is known in which a positive resist film is formed as a mask material on a polyimide resin film that has been heat-treated at 110 to 160 ° C., and an alkaline aqueous solution is used to perform patterning simultaneously with the resist.

In recent years, a general formula (II), which is a low dielectric constant material, has been used as an insulating film corresponding to high-speed response of various electronic parts.

[Chemical 2] (In the formula, R ¹ is a tetravalent organic group, R ² is a divalent organic group, n
Represents an integer of 1 or more, and at least one of R ¹ and R ² has a fluorine atom). These fluorine-containing polyimide resin films have a low dielectric constant of 2.7 or less.

However, when a pattern is formed on these low dielectric constant material films by the method (1), J-100 (trade name of Nagase & Co., Ltd.), S-502, S-502A (manufactured by Tokyo Ohka Kogyo). There is a problem that the coating film is dissolved in a widely used negative resist stripping solution such as a product name). Further, when the pattern is formed by the method (2), the coating film is cracked during the positive resist film formation, and the coating film is not etched by an alkaline aqueous solution such as an aqueous solution of tetramethylammonium hydroxide (NMD-3: manufactured by Tokyo Ohka Kogyo Co., Ltd.). Moreover, when the positive resist film is stripped with a positive resist stripping solution such as -n-butyl acetate, ethyl cellosolve acetate, or methyl ethyl ketone, there is a problem that the coating film is stripped together.

[0006]

DISCLOSURE OF THE INVENTION The present invention solves the above-mentioned problems of the prior art by developing a photosensitive resin film as a mask material and etching a low dielectric constant material film as a protective film at the same time, thereby cracking It is intended to provide a method for producing a fluorine-containing polyimide resin film pattern capable of forming an excellent protective film that does not generate

[0007]

The present invention provides a compound of general formula (I) obtained by reacting a tetrabasic acid dianhydride with a diamine in an organic solvent.

[Chemical 3] (In the formula, R ¹ is a tetravalent organic group, R ² is a divalent organic group, R ²
Is hydrogen or an alkyl group having 4 or less carbon atoms, n is an integer of 1 or more, and at least one of R ¹ and R ² has a fluorine atom) is applied onto a substrate, A fluorine-containing polyimide resin film is formed by heat treatment in the range of 200 ° C., a photosensitive polyimide resin film is formed on this film, and then exposed through a photomask, and then a photosensitive polyimide resin film is formed by a developing solution. A method for producing a pattern of a fluorine-containing polyimide resin film, characterized by performing development processing and etching processing of the fluorine-containing polyimide resin film at the same time, and removing the photosensitive polyimide resin film after the development processing with an alkaline aqueous solution. And a method for producing a fluorine-containing polyimide resin film pattern.

The polyamic acid solution represented by the above general formula (I) used in the present invention is, for example, N-methyl-2-pyrrolidone, N, N-dimethylacetamide, xylene,
It can be obtained by stirring and reacting tetrabasic acid dianhydride and diamine in an organic solvent such as butyl cellosolve acetate and diisobutyl ketone under anhydrous conditions, preferably at a temperature of 50 ° C. or lower. In the present invention, it is necessary to use a compound having a fluorine atom in at least one of tetrabasic acid dianhydride and diamine.

As the fluorine-containing diamine, diaminobenzotrifluoride, bis (trifluoromethyl) phenylenediamine, diaminotetra (trifluoromethyl) benzene, diamino (pentafluoroethyl) benzene, 2,2'-bis (trifluoro) Methyl) benzidine, 3,3′-bis (trifluoromethyl) benzidine, 2,2′-bis (trifluoromethyl) -4,4 ′
-Diaminodiphenyl ether, 3,3'-bis (trifluoromethyl) -4,4'-diaminodiphenyl ether, 3,3 ', 5,5'-tetrakis (trifluoromethyl) -4,4'-diaminodiphenyl ether,
3,3′-bis (trifluoromethyl) -4,4′-diaminobenzophenone, bis (aminophenoxy) di (trifluoromethyl) benzene, bis (aminophenoxy) tetrakis (trifluoromethyl) benzene, bis [(tri Fluoromethyl) aminophenoxy] benzene, bis [(trifluoromethyl)) aminophenoxy] biphenyl, bis {[(trifluoromethyl)) aminophenoxy] phenyl} hexafluoropropane,
2,2-bis {4- (p-aminophenoxy) phenyl} hexafluoropropane, 2,2-bis {4- (m-
Aminophenoxy) phenyl} hexafluoropropane,
2,2-bis {4- (o-aminophenoxy) phenyl} hexafluoropropane, 2- {4- (p-aminophenoxy) phenyl} -2- {4- (m-aminophenoxy) phenyl} hexafluoropropane , 2- {4-
(M-Aminophenoxy) phenyl} -2- {4- (o
-Aminophenoxy) phenyl} hexafluoropropane, 2- {4- (o-aminophenoxy) phenyl}-
2- {4- (p-aminophenoxy) phenyl} hexafluoropropane or the like is used.

As the diamine containing no fluorine atom,
m-phenylenediamine, p-phenylenediamine, benzidine, 4,4 "-diaminoterphenyl, 4,4-
Diamino quarterphenyl, 4,4'-diaminodiphenyl ether, 4,4'-diaminodiphenylmethane, diaminodiphenyl sulfone, 2,2-bis (p-
Aminophenyl) propane, 2,2-bis (p-aminophenyl) hexafluoropropane, 1,5-diaminonaphthalene, 2,6-diaminonaphthalene, 3,3′-dimethylbenzidine, 3,3′-dimethoxybenzidine,
3,3'-dimethyl-4,4'-diaminodiphenyl ether, 3,3'-dimethyl-4,4'-diaminodiphenylmethane, 1,4-bis (p-aminophenoxy)
Benzene, 4,4'-bis (p-aminophenoxy) biphenyl, 2,2-bis {4- (p-aminophenoxy) phenyl} propane, the following general formula (III)

[Chemical 4] A diamine represented by (in both formulas, m is an integer of 1 to 3), 2,3,5,6-tetraamino-p-phenylenediamine, or the like is used.

In the reaction, in order to improve adhesion with glass, ceramics, metals, etc., the following general formula (I
V)

[Chemical 5] Or the following general formula (V)

[Chemical 6] (In both formulas, R ₂ and R ₄ are divalent organic groups, R ₁ and R ₃ are monovalent organic groups, and p and q are integers greater than 1.) be able to.

Fluorine-containing tetrabasic acid dianhydrides include (trifluoromethyl) pyromellitic acid, bis (trifluoromethyl) pyromellitic acid, 5,5'-bis (trifluoromethyl) -3,3 ', 4,4'-tetracarboxybiphenyl, 2,2 ', 5,5'-tetrakis (trifluoromethyl) -3,3', 4,4'-tetracarboxybiphenyl, 5,5'-bis (trifluoromethyl) )
-3,3 ', 4,4'-tetracarboxydiphenyl ether, 5,5'-bis (trifluoromethyl) -3,
3 ', 4,4'-tetracarboxybenzophenone, bis [(trifluoromethyl) dicarboxyphenoxy]
Benzene, bis [(trifluoromethyl) dicarboxyphenoxy] biphenyl, bis [(trifluoromethyl) dicarboxyphenoxy] (trifluoromethyl)
Benzene, bis [(trifluoromethyl) dicarboxyphenoxy] bis (trifluoromethyl) biphenyl,
Bis [(trifluoromethyl) dicarboxyphenoxy] diphenyl ether, bis (dicarboxyphenoxy) (trifluoromethyl) benzene, bis (dicarboxyphenoxy) bis (trifluoromethyl) benzene, bis (dicarboxyphenoxy) tetrakis (trifluoro Methyl) benzene, bis (dicarboxyphenoxy) bis (trifluoromethyl) biphenyl, bis (dicarboxyphenoxy) tetrakis (trifluoromethyl) biphenyl, 2,2-bis (3,4-dicarboxyphenyl) hexafluoropropane, 2,2-bis [4- (3,4-dicarboxyphenoxy) phenyl]
Acid dianhydrides of carboxylic acids such as hexafluoropropane and derivatives of these compounds such as acid halides and esters are used.

The tetrabasic acid dianhydride containing no fluorine atom includes pyromellitic acid, 3,3 ', 4,4'-tetracarboxybiphenyl, 2,3,3', 4'-tetracarboxybiphenyl and 3 , 3 ', 4,4'-tetracarboxydiphenyl ether, 2,3,3', 4'-tetracarboxydiphenyl ether, 3,3 ', 4,4'
-Tetracarboxybenzophenone, 2,3,3 ',
4'-tetracarboxybenzophenone, 2,3,6
7-tetracarboxynaphthalene, 1,4,5,8-tetracarboxynaphthalene, 1,2,5,6-tetracarboxynaphthalene, 3,3 ', 4,4'-tetracarboxydiphenylmethane, 2,2-bis ( 3,4-dicarboxyphenyl) propane, 3,3 ', 4,4'-tetracarboxydiphenyl sulfone, 3,4,9,10
-Tetracarboxyperylene, 2,2-bis [4-
(3,4-Dicarboxyphenoxy) phenyl] propane, 1,3-bis (3,4-dicarboxyphenyl)-
1,1,3,3-tetramethyldisiloxane, p-terphenyl-3,4,3 ″, 4 ″ -tetracarboxylic acid, m
Acid dianhydrides of aromatic carboxylic acids such as terphenyl-3,4,3 ″, 4 ″ -tetracarboxylic acid and derivatives of these compounds such as acid halides and esters are used.

In the present invention, the photosensitive polyimide resin film is obtained by applying a photosensitive polyamic acid solution onto the fluorine-containing polyimide resin film and drying it. There is no particular limitation on the photosensitive polyamic acid, for example, a photosensitive polyamic acid having a photosensitive group introduced by an ester bond and a sensitizer, a photopolymerization initiator, etc. added thereto, or a polyamic acid having a carbon-carbon double bond. A photopolymerization initiator in addition to the amine compound,
Sensitizers, bis azide, etc. added, unsaturated compounds such as 1,6-hexanediol diacrylate, photopolymerization initiators, sensitizers, etc. in the reaction product obtained by reacting polyamic acid with isocyanate ethyl methacrylate And the like are preferably used. Examples of commercially available products thereof include PL-2035 and PL-2135 (trade name, manufactured by Hitachi Chemical Co., Ltd.). Further, the polyamic acid may have a siloxane bond.

The developer used in the present invention is N-
A developer containing a polar organic solvent such as methyl-2-pyrrolidone, N, N-dimethylacetamide, and dimethyl sulfoxide as a main component can be used.

In the present invention, the fluorine-containing polyamic acid solution applied on a substrate such as a wafer has a temperature of 160 ° C. to 2 ° C.
Heat treatment is performed at a temperature of 00 ° C. to obtain a fluorine-containing polyimide resin film. When the heat treatment temperature is lower than 160 ° C., the fluorine-containing polyimide resin film is dissolved in the photosensitive polyamic acid composition and cracks occur. On the other hand, when the temperature exceeds 200 ° C., it becomes difficult to perform etching with the photosensitive polyimide precursor developing solution. The treatment time preferably does not exceed 1 hour.
The photosensitive polyamic acid composition coated on the fluorine-containing polyimide resin film is heat-treated at a relatively low temperature of usually 60 to 100 ° C., preferably 60 to 80 ° C. for 1 hour or less on a hot plate or the like. It is a photosensitive polyimide resin film.

FIG. 1 is an explanatory view of a method of manufacturing a fluorine-containing polyimide resin film pattern showing an embodiment of the present invention.
In the figure, a part of a wiring layer 2 made of aluminum (Al) formed in a predetermined shape on a semiconductor substrate 1 is exposed at an inorganic insulating layer 3 (so-called passivation film) made of a silicon oxide film to form an electrode (bonding pad). ) Is formed, and a fluorine-containing polyimide resin film 4 is formed on this semiconductor wafer.
Are stacked. The fluorine-containing polyimide resin film 4 is
It is formed by spin-coating a polyamic acid solution on a semiconductor wafer, heat-treating at a temperature of 160 to 200 ° C. to remove the solvent, and dehydration ring closure. Then, a photosensitive polyimide resin film 5 is formed on the fluorine-containing polyimide resin film 4 by applying a photosensitive polyimide precursor resin composition in the same manner as the above-mentioned fluorine-containing polyimide resin film and heat-treating at 60 to 100 ° C. (FIG. 1a).

Next, after exposure through a photomask, the development of the photosensitive polyimide resin film 5 and the etching of the fluorine-containing polyimide resin film 4 are simultaneously processed by a well-known photo-etching technique using a developing solution to obtain a predetermined pattern. The pattern 6 is formed on the portion, and the Al bonding pad portion 7 is exposed. At this time, a part of the exposed portion of the photosensitive polyimide resin film 5 is also dissolved and removed by the developer (FIG. 1b). The entire photosensitive polyimide resin film 5 may be removed. The surface protective film composed of the fluorine-containing polyimide resin film 4 and / or the photosensitive polyimide resin film 5 is 100 when moisture is absorbed in the above step or imidization is not sufficient.
Heat treatment is performed at a temperature of up to 350 ° C. for 3 hours or less.

Further, in the present invention, as shown in FIG. 2, the photosensitive polyimide resin film 5 remaining after forming the pattern can be removed with an alkaline aqueous solution such as a tetramethylammonium hydroxide aqueous solution, if necessary. it can. The pattern shape in the present invention is the shape of the bottom of a scribe line, a through hole, etc. formed in a polyimide resin film.

[0020]

EXAMPLES The present invention will be described in detail below with reference to examples. Example 1 88.66 g of 2,2-bis [4- (4-aminophenoxy) phenyl] hexafluoropropane and 630 g of N-methyl-2-pyrrolidone and 1,3-bis (aminopropyl) tetramethyldisiloxane 4 0.72 g was dissolved with stirring, and 84.41 g of 2,2-bis (3,4-dicarboxyphenyl) hexafluoropropane dianhydride was gradually added to the mixture, which was reacted at room temperature for 6 hours and then stirred at 80 ° C. for 8 hours. A fluorinated polyamic acid solution having a viscosity of 80 poise and a resin content of 21.3% by weight was obtained. In the step of FIG. 1a, this solution is applied onto the semiconductor substrate 1 on which the wiring layer 2 and the inorganic insulating film layer 3 are formed by spin coating at 3800 rpm for 30 seconds, and then on a hot plate at 100 ° C. for 90 seconds.
Further, heat treatment (prebaking) was performed at 180 ° C. for 90 seconds to form a fluorine-containing polyimide resin film 4 (protective film layer) having a thickness of 6.0 μm. Next, a photosensitive polyamic acid composition (PL-2035, viscosity 35 poise, resin concentration 15.3% by weight, trade name manufactured by Hitachi Chemical Co., Ltd.) was applied to the layer 4 as 4000.
After spin coating for 60 seconds at rpm, heat treatment (prebaking) was performed for 90 seconds at 80 ° C. using a hot plate to form a photosensitive polyimide resin film 5 having a film thickness of 3.2 μm.

Next, in the process of FIG. 1b, in order to selectively remove only the bonding pad portion and the scribe line which are predetermined portions of the protective film layer 4, the through hole size is 100 μm square and the scribe line width size is 70 μm.
After exposure by a known photo-etching technique through a negative chrome mask of, using a developer PL-DEVELOPER-2N (trade name, manufactured by Hitachi Chemical Co., Ltd.) containing N-methyl-2-pyrrolidone as a main component, By the static paddle method at 25 ° C. for 5.5 minutes, the photosensitive polyimide resin film layer 5 is developed and the fluorine-containing polyimide resin film layer 4 is etched at the same time to form the pattern portion 6 and the bonding pad which is the wiring layer 2. Part of the part 7 (130 × 130 μm) was exposed. The bottom of the pattern portion 6 of the fluorine-containing polyimide resin film layer 4 on the inorganic insulating layer 3 has a size of 100 × 100 μm. The photosensitive polyimide resin film 5 formed on the fluorine-containing polyimide resin film 4 by the development and etching treatment was dissolved to have a film thickness of 1.8 μm.

Next, using a dryer in a nitrogen atmosphere, 140 ° C.
For 30 minutes, then 200 ° C for 30 minutes, then 350
A heat treatment was performed at 60 ° C. for 60 minutes to obtain a surface protective film having a film thickness of 6.3 μm and composed of the photosensitive polyimide resin film 5 and the fluorine-containing polyimide resin film 4 (FIG. 1b). This surface protective film is composed of a photosensitive polyimide resin film 5 and a fluorine-containing polyimide resin film 4
No peeling was observed between the interfaces with and, and the pattern shape was good.

Example 2 In a mixed solvent of 640 g of N-methyl-2-pyrrolidone and 160 g of diisobutyl ketone, 2,2-bis [4- (4-
101.9 g of aminophenoxy) phenyl] hexafluoropropane, 10.5 g of 4,4′-diaminodiphenyl ether and 12.43 g of 1,3-bis (aminopropyl) tetramethyldisiloxane were dissolved with stirring.
84.39 g of 3,3 ', 4,4'-benzophenonetetracarboxylic dianhydride was gradually added and reacted at room temperature for 5 hours, and then stirred at 80 ° C for 8 hours to have a viscosity of 40 poise and a resin content concentration of 18.6. A wt% fluorinated polyamic acid solution was obtained. In the step of FIG. 1a, the solution was spin-coated on the semiconductor substrate 1 at 3000 rpm for 30 seconds, and then prebaked at 100 ° C. for 90 seconds and then at 200 ° C. for 90 seconds by a hot plate to obtain a fluorine-containing polyimide having a thickness of 5.2 μm. The resin film 4 was formed. A photosensitive polyimide resin film 5 was formed on the layer 4 in the same manner as in Example 1.

Next, after exposing in the same manner as in Example 1, P
Using the L-DEVELOPER-2N at 25 ° C. for 6 minutes by the static paddle method, the development of the photosensitive polyimide resin film layer 5 and the etching of the fluorine-containing polyimide resin film layer 4 are simultaneously performed to form a pattern portion and wiring. A part of the bonding pad portion 7, which is the layer 2, was exposed. Next, Example 1
Heat treatment is carried out in the same manner as in, and the photosensitive polyimide resin film 5
Film thickness of 5.1μ consisting of fluorinated polyimide resin film 4
m surface protective film was obtained. The surface protective film had a good pattern shape without peeling between the interfaces between the photosensitive polyimide resin film 5 and the fluorine-containing polyimide resin film 4.

Example 3 The surface protective film composed of the photosensitive polyimide resin film 5 and the fluorine-containing polyimide resin film 4 formed in Example 1 was
A tetramethylammonium hydroxide aqueous solution NMD-3 (trade name of Tokyo Ohka Kogyo Co., Ltd.), which is a positive resist developer, was used to perform a stationary paddle treatment for 90 seconds at room temperature to dissolve and remove the upper photosensitive polyimide resin film layer 5. .. Then, put it in a hot air dryer, and heat it at 200 ° C for 30 minutes and then at 350 ° C for 6 minutes.
A heat treatment was performed for 0 minutes to form a surface protective film made of a fluorine-containing polyimide resin film 4 having a film thickness of 5 μm. This surface protective film showed a good pattern shape without a residue of the photosensitive polyimide resin film in the through hole pattern portion. Moreover, no crack was observed.

Comparative Example 1 In Example 1, after coating the fluorine-containing polyamic acid solution, the hot plate was used for 2 minutes at 100 ° C.
A fluorinated polyimide resin film having a thickness of 6 μm was formed in the same manner as in Example 1 except that prebaking was performed at 50 ° C. for 2 minutes, and a photosensitive polyimide resin was formed on this layer in the same manner as in Example 1. A film 5 was formed to obtain a surface protective film,
After the spin coating, it was dissolved in a part of the fluorine-containing polyimide resin film layer 4 and a crack was generated.

Further, the surface protection film thus obtained was subjected to development of a photosensitive polyimide resin film and fluorine-containing polyimide resin film in the same manner as in Example 1 using a mixed solution of dimethylformamide and a methyl alcohol component as a developing solution. Etching was performed to form a pattern, but the etching time was 3
A crack occurred in the surface protective film in about 4 minutes.

[0028]

According to the method for producing a pattern of the present invention, a photosensitive polyimide resin film can be used as a mask material by heat treating a fluorinated polyamic acid solution at a temperature of 160 to 200 ° C. Development and etching can be performed at the same time when manufacturing
It is possible to form a fluorine-containing polyimide resin film that does not cause cracks.

[Brief description of drawings]

FIG. 1 is a process explanatory view of a method of manufacturing a fluorine-containing polyimide resin film pattern showing an embodiment of the present invention.

FIG. 2 is a diagram showing an example of a fluorine-containing polyimide resin film pattern obtained by the production method of the present invention.

[Explanation of symbols]

1 ... Semiconductor substrate, 2 ... Wiring layer, 3 ... Inorganic insulating layer, 4 ... Fluorine-containing polyimide resin film (protective film), 5 ... Photosensitive polyimide resin film, 6 ... Pattern part, 7 ... Al bonding pad part.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification number Office reference number FI technical display location G03F 7/26 511 7124-2H H01L 21/027 21/312 B 8518-4M

Claims (2)

[Claims] 1. A compound of the general formula (I) obtained by reacting a tetrabasic acid dianhydride with a diamine in an organic solvent. (In the formula, R ¹ is a tetravalent organic group, R ² is a divalent organic group, R ²
Is hydrogen or an alkyl group having 4 or less carbon atoms, n is an integer of 1 or more, and at least one of R ¹ and R ² has a fluorine atom) is applied onto a substrate, A fluorine-containing polyimide resin film is formed by heat treatment in the range of 200 ° C., a photosensitive polyimide resin film is formed on this film, and then exposed through a photomask, and then a photosensitive polyimide resin film is formed by a developing solution. A method for producing a fluorine-containing polyimide resin film pattern, which comprises performing development processing and etching processing of the fluorine-containing polyimide resin film at the same time. 2. The method for producing a fluorine-containing polyimide resin film pattern according to claim 1, wherein the photosensitive polyimide resin film after the development treatment is removed with an alkaline aqueous solution.