JP2594545B2 - Method for manufacturing semiconductor device - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a method for manufacturing a semiconductor device, and more particularly, to a method for manufacturing an interlayer insulating film in a multilayer wiring structure.

[Conventional technology]

Conventionally, as an interlayer insulating film of this kind, a polyamic acid formed by reacting an aromatic tetracarboxylic dianhydride with an aromatic diamine, for example, pyromellitic anhydride and 4.4'-diaminodiphenyl ether And a polyamic acid formed by reacting the same.

[Problems to be solved by the invention]

However, when these polyamic acid solutions are applied on a semiconductor substrate and heat-treated to form a polyimide film, heat treatment at 350 ° C. or more for about 1 hour is usually required to completely imidize the amic acid. . If the temperature is lower than this, the imidization reaction is not completely performed, and the residual amino group and the like increase the leak current, which makes it unsuitable as an interlayer insulating film.

In the case where the semiconductor substrate is made of a thermally weak material, for example, gallium arsenide, applying a high-temperature heat treatment is not likely to lower the electrical characteristics in terms of fluctuation and deterioration. In a semiconductor device mainly composed of gallium arsenide, a temperature of 300 ° C. or less is desirable for about one hour.

Therefore, a polyamic acid solution that is completely imidized by a heat treatment at 300 ° C. or lower for about one hour is desired.

An object of the present invention has solved the above problems. That is,
An object of the present invention is to provide a method for manufacturing an interlayer insulating film in a multilayer wiring structure using a resin film that can be formed by a low-temperature heat treatment.

[Means for solving the problem]

The method of manufacturing a semiconductor device according to the present invention includes the following general formula: (R ³ and R ⁴ each independently represent an alkyl group having 1 to 6 carbon atoms,
Or an amide group and an imide group formed by reacting an aminosilicon compound represented by a phenyl group and 1 ≦ K ≦ 3) with a diamine containing no silicon atom in the molecule with an aromatic tetracarboxylic dianhydride. Is 1: n
The method is characterized by comprising a step of applying a polyamic acid solution (n ≧ 0.1) to a main surface of a semiconductor substrate on which a metal multilayer wiring is to be formed, and a step of heat treatment thereafter.

The appropriate range of the average molecular weight of the polyamic acid used in the present invention is a measured value of the logarithmic viscosity number under the above-mentioned constant conditions is 0.05 to 5 d.
l / g and soluble in a suitable solvent.

The logarithmic viscosity number (η inh) is as defined by the measurement conditions. (Here, using a Ubbelohde viscometer, the value of 0.5% by weight in a solvent having the same composition as that of the polymerization
Is a value measured at 1 ° C., η ₀ is a measured value of the same solvent at the same temperature using an Ubbelohde viscometer, and C is a concentration of 0.
5 g / dl. ).

 The raw material of the present invention will be described.

The following compounds can be mentioned as the tetracarboxylic dianhydride represented by (R ': tetravalent carbocyclic aromatic).

Pyromellitic dianhydride, 3,3 ', 4,4'-biphenyltetracarboxylic dianhydride, 2,2', 3,3'-biphenyltetracarboxylic dianhydride, 2,3,3 ', 4'-Biphenyltetracarboxylic dianhydride, 3,3', 4,4'-benzophenonetetracarboxylic dianhydride, 2,3,3 ', 4'-benzophenonetetracarboxylic acid Dianhydride, 2,2 ', 3,3'-benzophenonetetracarboxylic dianhydride, bis (3,4-
Dicarboxyphenyl) -ether dianhydride, bis (3,
4-dicarboxyphenyl) -sulfone dianhydride, 1,2,
5,6-naphthalenetetracarboxylic dianhydride, 2,3,6,7-
Naphthalenetetracarboxylic dianhydride and the like.

Further, specific examples of the diamine represented by the formula NH ₂ —R ² —NH ₂ (R ² : an araliphatic group or a carbocyclic aromatic group having 6 to 30 carbon atoms) include the following compounds. .

4,4'-diaminodiphenyl ether, 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenylsulfone, 4,4'-diaminodiphenylsulfide, 4,4'-
Diaminodiphenylthioether, 4,4'-di (meta-
(Aminophenoxy) diphenylsulfone, 4,4'-di (para-aminophenyl) diphenylsulfone, ortho-phenylenediamine, meta-phenylenediamine, para-phenylenediamine, benzidine, 2,2'-diaminobenzophenone , 4,4'-diaminobenzophenone,
4,4'-diaminodiphenyl-2,2'-propane, 1,5-
Aromatic diamines such as diaminonaphthalene and 1,8-diaminonaphthalene;

Next, examples of the aminosilicon compound represented by the formula (1) or (2) include the following compounds.

As a preferable solvent (hereinafter, sometimes referred to as a reaction solvent) for reacting the above-mentioned raw material compounds in a solvent, N-
Methyl-2-pyrrolidone, N, N-dimethylacetamide, N, N-dimethylformamide, dimethylsulfoxide, tetramethylurea, pyridine, dimethylsulfone,
Hexamethylphosphoramide, methylformamide, N
-Acetyl-2-pyrrolidone, toluene, xylene, methyl cellosolve, ethyl cellosolve, butyl cellosolve, diethylene glycol monomethyl ether, diethylene glycol dimethyl ether, cyclopentanone,
One or more kinds such as cyclohexanone can be used.

 The reaction is performed in two stages.

The first-stage reaction is performed at 0 ° C. or higher in the presence of the above reaction solvent.
0.2 to 6 at a temperature of less than 60C, preferably 3C or more and less than 30C.
It is good to react for a time.

After the completion of the first-stage reaction, the second-stage reaction is further carried out from the first-stage reaction temperature in the presence of a silylating agent such as trimethylethoxysilane or the like, so that the temperature is at least 60 ° C and less than 200 ° C, preferably at least 60 ° C. It is preferable to heat at a temperature of less than 110 ° C. for 0.5 to 30 hours, and to carry out the reaction in the presence of an appropriate amount of water including the water generated at that time.

It is particularly preferable that the mixing ratio of the raw materials is such that all the acid anhydride groups and all the amino groups are within ± 10% from the equivalence relation.

〔Example〕

Next, the present invention will be described based on embodiments with reference to the drawings. In the present embodiment, 3 / 4-3'-4'-
Benzophenonetetracarboxylic dianhydride, 4.4'-
Diaminodiphenyl ether and P-aminophenyltrimethoxysilane were used, and trimethylethoxysilane was used as a silylating agent. Medium 30 ℃ 2
The reaction was carried out at 100 ° C for 11 hours, and a concentration of 12% by weight in which 80% of the amic acid portion was converted to imide groups
A varnish having a rotational viscosity of 630 centipoise at 25 ° C. was synthesized. The logarithmic viscosity number of the polymer in this varnish is 0.66dl / g
Met. This varnish was used as a coating solution.

1 (a) to 1 (f) show an embodiment 2 of the present invention.
FIG. 10 is a process cross-sectional view in the case of forming a layered aluminum wiring structure.

As shown in FIG. 1A, polysilicon electrodes 103 and 103 'are formed on a device substrate 101 on which a semiconductor device active portion is formed via a phosphorus glass film 102 by chemical vapor deposition. A phosphorus glass film 104 is formed by growth. Next, first openings 105 and 105 'for establishing electrical conduction between the polysilicon electrode and the first aluminum wiring are provided by known lithography and dry etching, as shown in FIG. To form an aluminum film having a thickness of about 1 .mu.m, and first aluminum wirings 105 and 106 'are formed by photolithography and dry etching as shown in FIG.

Next, as shown in FIG. 3 (d), the coating solution according to the present invention is spin-coated at 2000 rpm for 30 seconds, 100 ° C. for 1 hour and 240 ° C. for 30 minutes, and further at 300 ° C. for 1 hour. Heat treatment is performed in a nitrogen gas atmosphere to form a resin film 107 having a thickness of about 1.5 μm. Next, about 0.1μ is used as an etching mask for the resin film.
(e) by forming a titanium metal film having a thickness of m by a sputtering method, etching the titanium metal film and the resin film by known photolithography and dry etching, and removing the titanium metal used as an etching mask. As shown, the first aluminum wirings 106, 106 '
And second openings 108 and 108 'for establishing electrical continuity with the second aluminum wiring.

Next, an aluminum film having a thickness of about 1 μm is formed by a sputtering method, and the second aluminum wiring 10 is formed by photolithography and dry etching as shown in FIG.
By forming 9,109 ', a two-layer aluminum wiring structure is formed.

If necessary, the above-described steps shown in FIGS. 1C to 1E can be repeated to form a multilayer wiring structure having three or more layers.

[Effect of the Invention] A flat interlayer insulating film according to the present invention can be formed at a low temperature, and is very useful as a multilayer wiring structure of a semiconductor device such as a gallium arsenide integrated circuit which cannot be subjected to a high-temperature heat treatment and a method of manufacturing the same. It is.

Furthermore, even when used as an interlayer insulating film of a multilayer structure of Al wiring, which is frequently used in a VLSI (ultra LSI) using a Si substrate, hillocks are not generated on the Al surface at a low temperature of 300 ° C. or less. Without, short-circuit between the lower layer Al and the upper layer Al, fatal defects for multilayer wiring can be almost avoided.
It also has great advantages.

[Brief description of the drawings]

1 (a) to 1 (f) are cross-sectional views showing steps in forming a two-layer aluminum wiring structure according to one embodiment of the present invention. 101 …… Element substrate, 102 …… Phosphor glass film, 103,103 ′…
... Polysilicon electrode, 104 ... Phosphor glass film, 105,105 '
... first opening, 106, 106 '... first aluminum wiring, 107 ... resin film based on the present invention, 108, 108' ... second
Openings, 109, 109 '... Second aluminum wiring.

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Kohei Eguchi 5-3-13-1 Shiba, Minato-ku, Tokyo Within NEC Corporation (72) Inventor Koichi Kunimune 12-12 Ichihara, Ichihara-shi (72) Inventor Yoshiya Kutsusawa 10-3, Otohmachi, Kanazawa-ku, Yokohama-shi (72) Inventor Yoichiro Numazawa 5-33-1, Shiba, Minato-ku, Tokyo Inside NEC Corporation (72) Inventor Kimimaro Yoshikawa, Shiba 5, Minato-ku, Tokyo 33-1, NEC Corporation (72) Inventor Kuniyuki Hamano 5-33-1, Shiba, Minato-ku, Tokyo NEC Corporation (72) Inventor Shiro Konone 5-12-6 Highland, Yokosuka City (56) References JP-A-61-293227 (JP, A) JP-A-61-108627 (JP, A) JP-A-62-70423 (JP, A) JP-A-61-287926 (JP, A)

Claims (1)

(57) [Claims] (1) The general formula is (R ³ and R ⁴ each independently represent an alkyl group having 1 to 6 carbon atoms,
Or an amide group and an imide group formed by reacting an aminosilicon compound represented by a phenyl group and 1 ≦ K ≦ 3) with a diamine containing no silicon atom in the molecule with an aromatic tetracarboxylic dianhydride. Is 1: n
A method for manufacturing a semiconductor device, comprising: a step of applying a polyamic acid solution (n ≧ 0.1) to a main surface of a semiconductor substrate on which a metal multilayer wiring is to be formed;