JPH08195565A - Manufacture of multi-layer wiring structure and semiconductor device - Google Patents

Abstract

PURPOSE: To provide a polyimide resin precursor of a specific composition with sufficient photosensitivity by adding acrylic acid and/or methacrylic acid to it and to flatten differences in the levels of wiring through interlayer isolation. CONSTITUTION: In the presence of solvent, 1.6 to 2 mols of monohydric alcohol with the number of carbon under 4 is added to 1mol of aromatic tetrabasic acid dianhydride and heated on a patterned substrate. Diester is used for all or part of the tetrabasic acid dianhydride, a photosensitive polymer composition, including a polyimide resin precursor 100 by weight and acrylic acid and/or methacrylic acid 1 to 400 by weight obtained by allowing 0.2 to 1mol of an amine compound and 0 to 0.8mol of a diamine compound, which are expressed by a formula (in the formula R<1> is an aromatic cyclic group, R<2> is a hydrocarbon group with the number of hydrogen or carbon under 3, and one R<2> may be different from another) to react with each other in the total quantity of 1mol of the amin compound and the diamine compound, is coated, dried, exposure-developed, and hardened. And an interlayer insulating film 51 and an upper wiring layer 7 are formed. This enables photosensitivity to be retained and differences in wiring levels to be eliminated.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a multilayer wiring structure in an electronic circuit component such as a semiconductor integrated circuit and a high-density mounting board, and a semiconductor device.

[0002]

2. Description of the Related Art In order to manufacture a multilayer wiring structure in a semiconductor integrated circuit or the like, SiO _{2 is} deposited on a substrate having a patterned wiring layer by a vapor deposition method such as vacuum deposition or CVD (chemical vapor deposition). A method is used in which an interlayer insulating film made of SiN or the like is formed, a through hole is opened, and then an upper wiring layer is formed. However, in the method of forming the interlayer insulating film by vapor phase epitaxy, the step of the lower wiring layer 4 remains as it is even after the formation of the interlayer insulating layer 5 as shown in FIG. There was a problem that the wiring layer was extremely thin at the portion and the wiring was easily broken. In FIG. 7, 1 is a substrate and 2 is a silicon dioxide film. Therefore, in order to improve this, as shown in FIG. 5, the formation of the interlayer insulating film 5'is obtained by applying a solution of a polyamic acid obtained from an aromatic diamine and an aromatic tetrabasic acid dianhydride and curing it. A method using polyimide has been proposed and is now widely used (Japanese Patent Publication No. 51-4).
4871).

On the other hand, when polyimide is used, the film processing is carried out by an etching process using a photoresist. Therefore, recently, a photosensitive polymer which also functions as a photoresist for the purpose of streamlining the film processing process. Investigations into the development of compositions are underway. this is,
First, a photosensitive polymer composition is applied in a solution state on a substrate, dried to form a film, and then exposed through a predetermined photomask,
Form a pattern by development, then 200-400 ° C
Is heat-treated at the temperature of, and finally polyimide is obtained. As a specific example, carbon-containing polyamic acid obtained from diamine, diaminosiloxane and tetrabasic acid dianhydride can be used.
A method of adding an amine compound having a carbon double bond and a bisazide compound is known (JP-A-57-1).
70929).

However, the degree of integration in electronic components such as semiconductor integrated circuits has been remarkably improved, and the wiring structure has become more and more multilayered, and the need for flattening wiring steps has further increased. On the other hand, in the polyamic acid obtained from the aromatic diamine and the aromatic tetrabasic acid dianhydride, the solubility of the polyamic acid in the solvent is very low, and the solution cannot be made to have a high concentration. The flatness of the step is not sufficient, and it is difficult to manufacture a multilayer wiring structure having two or more layers. Further, with respect to a very fine groove-shaped pattern, there is a problem that the embedding property of the polyimide film is insufficient and a void is generated in the film of the groove portion. On the other hand, the higher the concentration of the polyamic acid solution applied on the base material having the patterned insulating layer, the higher the flattening rate of the wiring step and the burying property of the groove-shaped pattern, and In order to increase the concentration of the polyamic acid solution, it has been reported that low molecular weight ester oligomerization is effective (JP-A-63-14452).

[0005]

However, a photopolymer composition obtained by photosensitizing a polyamic acid solution obtained by the conventional low molecular weight ester oligomerization described above by a conventional method has a high esterification rate. The photosensitivity is insufficiently provided, and when the esterification rate is lowered, the flattening rate of the wiring step is lowered, and the two performances are not compatible with each other.

[0006]

DISCLOSURE OF THE INVENTION As a result of intensive studies made by the present inventors in view of these drawbacks of the prior art, as a result of adding acrylic acid and / or methacrylic acid to a polyimide resin precursor having a specific composition, A method of manufacturing a multilayer wiring structure using a photosensitive polymer composition that solves the problems has been reached.

According to the present invention, on a substrate having a patterned wiring layer, 1 mol of an aromatic tetrabasic dianhydride in the presence of a solvent, 1 monohydric alcohol having 4 or less carbon atoms is used. After adding 6 to 2.0 mol and heating to form all or part of the tetrabasic acid dianhydride as a diester, the compound of the general formula (I)

Embedded image (Wherein R ¹ represents an aromatic cyclic group, R ² represents hydrogen or a hydrocarbon group having 3 or less carbon atoms, and R ^{2 s} may be different from each other). 100 parts by weight of a polyimide resin precursor obtained by reacting 1 mol of the diamine compound with 0 to 0.8 mol of the amine compound and the diamine compound in a total amount of 1.0 mol and acrylic acid and / or methacrylic acid 1 to Manufacture of a multilayer wiring structure in which a photosensitive polymer composition containing 400 parts by weight is coated, dried, exposed and developed to form a via hole, and further cured to form an interlayer insulating film, and an upper wiring layer is formed thereon. And a semiconductor device having this multilayer wiring structure.

The substrate having a wiring layer having a pattern according to the present invention is, for example, a silicon semiconductor substrate having an aluminum wiring layer formed thereon, a ceramic high-density mounting substrate having a copper wiring layer formed thereon, or a ceramic having a copper wiring layer formed thereon. Refers to a hybrid substrate.

The polyimide resin precursor used in the photosensitive polymer composition used in the present invention is a monovalent compound having 4 or less carbon atoms in the above ratio with respect to the aromatic tetrabasic dianhydride in the presence of a solvent. The alcohol can be obtained by reacting the amine compound and the diamine compound in the above proportions after adding part of the tetrabasic acid dianhydride to all or part of the diester by heating.
The diamine compound may not be used.

The solvent used in the esterification of the aromatic tetrabasic acid dianhydride in the present invention includes N-methyl-2-pyrrolidone, N, N-dimethylacetamide, N, N-dimethylformamide and dimethylsulfone. An amide-based solvent such as xide is preferable.

Examples of the aromatic tetrabasic dianhydride used in the present invention include pyromellitic dianhydride, 3,
3 ', 4,4'-benzophenone tetracarboxylic dianhydride, 3,3', 4,4'-biphenyl ether tetracarboxylic dianhydride, 3,3 ', 4,4'-biphenyl tetracarboxylic dianhydride Anhydride, 1,2,5,6-naphthalenetetracarboxylic dianhydride, 2,3,5,6-pyridinetetracarboxylic dianhydride, 3,4,9,10-perylenetetracarboxylic dianhydride , 4,4′-sulfonyldiphthalic acid dianhydride and substituted products thereof, and one or more of them may be used.

As the monohydric alcohol for esterifying the aromatic tetrabasic dianhydride of the present invention, one or more of methanol, ethanol, propanol, butanol, ethylene glycol monomethyl ether and the like having 4 or less carbon atoms can be used. Is used. At this time, if the carbon number is 5 or more, a good cured film cannot be obtained. The amount of alcohol and / or alcohol derivative used is limited to the range of 1.6 to 2.0 mol per 1 mol of aromatic tetrabasic dianhydride. If it is less than 1.6 mol, a good pattern cannot be obtained,
If it exceeds 2.0 mol, the viscosity of the varnish will be reduced.

The amine compound represented by the general formula (I) used in the present invention is, for example, 4,4'-diaminodiphenyl ether-3-carboxamide, 3,4 '.
-Diaminodiphenyl ether-4-carboxamide and the like.

As the diamine compound used in the present invention as needed, metaphenylenediamine, 3,4-diaminodiphenyl ether, 3,3 '
-Diaminodiphenyl sulfone, 3,3'-diaminodiphenyl sulfide, paraphenylenediamine, 4,
4'-diaminodiphenyl ether, 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenyl sulfone, 4,4'-diaminodiphenyl sulfide,
3,3 ', 5,5'-tetramethyl-4,4'-diaminodiphenylmethane, 2,2'-bis (4-aminophenyl) propane, 4,4'-methylenedianiline, 4,
4'-diaminodiphenyl ether-3-carbonamide and the like can be mentioned, and these can be used alone or in combination of two or more kinds.

If necessary, 1,3-bis (3-
Aminopropyl) -1,1,3,3-tetramethyldisiloxane and other siloxane-based diamines may be used alone or in combination of two or more. At this time, the amount of these siloxane-based diamines used is preferably within 20 mol% with respect to the total number of moles of the amine compound and the diamine compound.

The reaction temperature of the esterification reaction in the present invention varies depending on the solvent used, but is 60 to 150.
It is preferable to carry out at a temperature of at most 90 ° C. in view of the sensitivity, resolution and development speed of the finally obtained photosensitive polymer composition.

The reaction of the partially or wholly esterified aromatic tetrabasic dianhydride of the present invention with the above amine compound and diamine compound cured the finally obtained photosensitive polymer composition. In order to maximize the heat resistance of the film, it is preferable that the total number of moles of the aromatic tetrabasic acid dianhydride and its esterified product and the total number of moles of the amine compound and the diamine compound are equimolar. Due to the photosensitivity of the composition, the above amine compound is in the range of 0.2 to 1 mol.

The mixing ratio of acrylic acid and / or methacrylic acid is 1 to 400 parts by weight based on 100 parts by weight of the polyimide resin precursor. If the mixing ratio is less than 1 part by weight or exceeds 400 parts by weight,
It adversely affects the developability and film quality of the final product, polyimide.

In the present invention, it is also possible to use a bisazide compound as a photocrosslinking agent for the purpose of further increasing the sensitivity.
For example 4,4'-diazidochalcone,

Embedded image

[Chemical 4] Etc.

The mixing ratio of the bisazide compound is preferably 0.1 to 100 parts by weight, particularly preferably 0.5 to 50 parts by weight, based on 100 parts by weight of the polyimide resin precursor. When the blending ratio is less than 0.1 part by weight,
If it exceeds 100 parts by weight, the developability and the storage stability of the varnish are adversely affected.

It is also possible to use a photopolymerization initiator for the purpose of further increasing the sensitivity of the photosensitive polymer composition used in the present invention. Examples of the photopolymerization initiator include Michler's ketone, anthrone, benzoin, 5-nitroazenaphthene, 2-methylbenzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin isobutyl ether, 2-t-
Butylanthraquinone, 1,2-benzo-9,10-anthraquinone, anthraquinone, methylanthraquinone, 4,4'-bis (diethylamino) benzophenone, acetophenone, benzophenone, thioxanthone, 1,5-acenaphthene, 2,2-dimethoxy-2. −
Phenylacetophenone, 1-hydroxycyclohexyl phenylton, 2-methyl- [4- (methylthio)
Phenyl] -2-morpholino-1 propanone, diacetyl, benzyl, benzyl dimethyl ketal, benzyl diethyl ketal, diphenyl disulfide, anthracene, 2,6-di (4'-diethylaminobenzal)-
4-methyl-4-azacyclohexanone and the like can be mentioned. The addition amount of the photopolymerization initiator is preferably in the range of 0.01 to 10% by weight with respect to the polyimide resin precursor.

It is also possible to use a dissolution accelerator for the purpose of shortening the development time. Examples thereof include benzenesulfonamide and benzenesulfonanilide. The addition amount of the dissolution accelerator is preferably in the range of 0.05 to 50% by weight with respect to the polyimide resin precursor.

A photosensitive polymer composition is applied on a substrate having a patterned wiring layer such as a silicon semiconductor substrate having a stepped surface or a ceramic high-density mounting substrate by using a spin coater, a printer, a sprayer or the like. Applied, preferably 8
After drying at a temperature of 0 ° C. to 150 ° C., exposure is performed according to a normal photolithography process, and the unexposed portion of the dried film of the photosensitive polymer composition is dissolved and removed with a developer to form a via hole. Examples of the developer include N-methyl-2-pyrrolidone, N-acetyl-2-pyrrolidone,
Aprotic polar solvents such as N, N-dimethylformamide, N, N-dimethylacetamide, dimethylsulfoxide, hexamethylphosphortriamide, dimethylimidazolidinone, N-benzyl-2-pyrrolidone, N-acetyl-ε-caprolactam. Is used alone or as a mixed solution with a non-solvent of polyamic acid, for example, methanol, ethanol, isopropyl alcohol, benzene, toluene, xylene, methyl cellosolve, water and the like.

Next, the relief pattern formed by the development is washed with a rinse solution to remove the developer.
As the rinse solution, a non-solvent of polyamic acid having good miscibility with the developing solution is used, and examples thereof include methanol, ethanol, isopropyl alcohol, benzene, toluene, xylene, methyl cellosolve, and water. Then, by curing, dehydration ring closure occurs, and an interlayer insulating film which is a film of a polyimide resin is formed, whereby a level difference can be covered and flattened at a specific portion of the substrate surface. The curing temperature is preferably in the range of 150 ° C to 450 ° C. When forming the above-mentioned coating, an adhesion aid such as aminosilane or epoxysilane may be added to the photosensitive polymer composition, if necessary, for the purpose of enhancing the adhesion to the substrate surface.

An upper wiring layer is vacuum-deposited, sputtered, and CVD on the interlayer insulating film in which the via hole is formed.
The multilayer wiring structure of the present invention can be obtained by forming it by using a known method such as (chemical vapor deposition). Further, the upper wiring layer is patterned, and the above manufacturing method is performed once or twice. By repeating the above,
A multilayer wiring structure including a wiring layer and an insulating layer is obtained, and the present invention provides a semiconductor device having such a multilayer wiring structure.

[0026]

EXAMPLES The present invention will be described below with reference to examples and comparative examples.

Example 1 a. Production of Photosensitive Polymer Composition 95.90 g of N-methyl-2-pyrrolidone and 3,3 ', 4 in a 0.2 liter flask equipped with a stirrer, a thermometer, a nitrogen introduction tube, and a Dimroth condenser tube. , 4'-biphenyltetracarboxylic dianhydride (52.46 g) was added, and 8
After heating to 0 ° C., 8.2 g of ethanol was added, and the mixture was further reacted at 90 ° C. for 2 hours to give biphenyltetracarboxylic dianhydride as a diester. Then add this solution to 4,4'-
Diaminodiphenyl ether-3-carboxamide 41.
22 g and 1,3-bis (3-aminopropyl) -1,
2.22 g of 1,3,3-tetramethyldisiloxane was charged and reacted at 25 ° C. for 5 hours and at 40 ° C. for 1 hour. The resin content of the obtained polyimide resin precursor composition is 50.
% By weight, it showed a viscosity of 150 cps (centipoise) at 25 ° C. 2.0 g of 2,3-di (4-azidobenzal) -4-carboxylcyclohexanone was added to 100 g of this solution.
0 g and 7.68 g of methacrylic acid were dissolved. The resin content of the obtained photosensitive polymer composition was 46% by weight and was 25
It showed a viscosity of 100 cps at ° C.

B. Manufacturing Semiconductor Device Having Multi-Layered Wiring Structure As shown in FIG. 1, first, a collector region C and a base region B are formed.
Then, a silicon dioxide film 2 was formed on the surface of the semiconductor substrate 1 on which the semiconductor element including the emitter region E is formed by the CVD method (chemical vapor deposition method). Then, a predetermined portion to be an electrode lead-out portion was removed by etching by a normal photolithography process, a via hole (window) 3 was provided in the silicon dioxide film, and a part of the emitter region and the base region were exposed. Further, an aluminum wiring layer was formed on the via hole by a sputtering method, and a photolithography process was performed to form a lower wiring layer 4. This wiring layer has a thickness of 1 μm and a thickness of 0.
It had a width of 5 to 2 μm. Next, the photosensitive polymer composition of the above a was applied onto the lower layer wiring using a spinner coater (FIG. 2). Then, it was dried at 80 ° C. for 120 seconds using a hot plate, and exposed (exposure amount 100 mJ / cm ² ) using a G-line stepper through a photomask 6 (FIG. 3). Next, development was carried out with a mixed solvent consisting of 75% by weight of N-methyl-2-pyrrolidone and 25% by weight of methanol, and then rinsed with ethanol to obtain a good pattern. Then, it was cured in a convection oven at 200 ° C. for 1 hour and then at 350 ° C. for 1 hour to obtain a polyimide interlayer insulating film 5 ′ having a thickness of 2 μm (FIG. 4). Then, the upper aluminum wiring layer 7 is formed by the sputtering method,
A semiconductor device having a two-layer wiring structure as shown in FIG. 5 was obtained. In the figure, 5'is an interlayer insulating film of polyimide.

C. Evaluation of flattening rate and embedding property The flattening rate of the initial step due to the polyimide film thus obtained is calculated by the following equation from the values of a and b in FIG.

[Equation 1] It was found to be about 90%. Further, when the silicon substrate was cut at the groove pattern portion and the cross-sectional shape was observed with a scanning electron microscope, it was found that any groove was sufficiently filled with polyimide resin.

D. Evaluation of Development Processability The photosensitive polymer composition of the present invention was applied onto a silicon substrate by a spinner in a film thickness similar to the above, and was applied using a hot plate.
After drying at 0 ° C. for 120 seconds, it was exposed (exposure amount: 1000 mJ / cm ² ) using a G-line stepper. After that, N-methyl-
Development was carried out with a mixed solvent consisting of 75% by weight of 2-pyrrolidone and 25% by weight of methanol, followed by rinsing with ethanol to obtain a good pattern.

Comparative Example 1 N-in a 0.2 liter flask equipped with the same stirrer, thermometer, nitrogen inlet tube and Dimroth condenser tube as in Example 1.
95.90 g of methyl-2-pyrrolidone, 3,3 ',
4,4'-biphenyltetracarboxylic dianhydride 52.
After charging 46 g into a flask and heating to 80 ° C., 8.2 g of ethanol was added and further reacted at 90 ° C. for 2 hours to make biphenyltetracarboxylic dianhydride as a diester. Next, this solution was charged with 41.22 g of 4,4'-diaminodiphenyl ether-3-carboxamide and 2.22 g of 1,3-bis (3-aminopropyl) -1,1,3,3-tetramethyldisiloxane. The reaction was carried out at 25 ° C for 5 hours and at 40 ° C for 1 hour. The resin component concentration of the obtained polyimide resin precursor composition was 50% by weight, and showed a viscosity of 150 cps at 25 ° C. 2,3 to 100 g of this solution
-2.00 g of di (4-azidobenzal) -4-carboxylcyclohexanone and 15.28 g of 3- (N, N-dimethylamino) propyl methacrylate were dissolved.
The resin content of the obtained photosensitive polymer composition is 42% by weight.
And showed a viscosity of 100 cps at 25 ° C. Hereinafter, in the same manner as in Example 1, the step flattening rate, the groove pattern embedding property,
The developability and the film state after development were evaluated. As a result, the flattening rate was 90% and the embedding property was also good, but when the same evaluation of the developability as in Example 1 was performed, there was no difference in the dissolution time between the exposed part and the unexposed part, and the pattern Not formed.

[0032]

According to the present invention, the step of the lower wiring layer can be almost completely flattened by the interlayer insulation by using the process of the photosensitive polymer composition which does not require the resist coating process. It is possible to inexpensively manufacture a semiconductor device having a multi-layered wiring structure in which there is almost no step difference caused by the above and wiring reliability is remarkably excellent.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a semiconductor device having a lower wiring layer.

FIG. 2 is a diagram showing a state in which a photosensitive polymer composition is applied onto a semiconductor device having a lower wiring layer.

FIG. 3 is a diagram showing a state in which a resist layer is formed on a polyimide film and exposed through a photomask.

FIG. 4 is a diagram showing a state in which the resist has been peeled off and the polyimide insulating layer forming step has been completed.

FIG. 5 is a cross-sectional view of a semiconductor device having a two-layer wiring structure planarized using polyimide.

FIG. 6 is a diagram showing a method of evaluating a flattening rate.

FIG. 7 is a cross-sectional view of an example of a conventional multilayer wiring structure in which a SiO ₂ film formed by vapor phase epitaxy is used as an interlayer insulating film.

[0033]

[Explanation of symbols]

 1 semiconductor substrate 2 silicon dioxide film 3 via hole (window) 4 lower wiring layer 5, 5'interlayer insulating film 6 photomask 7 upper wiring layer

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical display location G03F 7/038 504 H01L 21/3205 21/768 H01L 21/90 A

Claims (3)

[Claims] 1. A monohydric alcohol having 4 or less carbon atoms in an amount of 1.6 to 1 mole of aromatic tetrabasic dianhydride in the presence of a solvent on a substrate having a patterned wiring layer.
After adding 2.0 moles and heating to form all or part of the tetrabasic acid dianhydride as a diester, the compound represented by the general formula (I): (Wherein R ¹ represents an aromatic cyclic group, R ² represents hydrogen or a hydrocarbon group having 3 or less carbon atoms, and R ^{2 s} may be different from each other). 100 parts by weight of a polyimide resin precursor obtained by reacting 1 mol of the diamine compound with 0 to 0.8 mol of the amine compound and the diamine compound in a total amount of 1.0 mol and acrylic acid and / or methacrylic acid 1 to A multilayer comprising applying a photosensitive polymer composition containing 400 parts by weight, drying, exposing and developing to form a via hole, and further curing to form an interlayer insulating film on which an upper wiring layer is formed. Wiring structure manufacturing method. 2. A method for manufacturing a multilayer wiring structure, wherein the upper wiring layer of the multilayer wiring structure obtained by the manufacturing method according to claim 1 is patterned, and the manufacturing method according to claim 1 is repeated once or twice or more. 3. A semiconductor device having a multilayer wiring structure according to claim 1.