JPH0732149B2 - Semiconductor device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor device capable of highly reliable operation even under high temperature and high humidity, and a multilayer wiring structure of the semiconductor device.

[Background of the Invention]

Conventionally, resin-encapsulated semiconductor devices have a higher temperature and humidity (65-85 ° C, 95%) than ceramic-encapsulated semiconductor devices.
It was inferior in terms of operational reliability at 121 ° C. and 2 atmospheric pressure supersaturated water vapor in relative humidity.

In a resin-sealed semiconductor device, a gap is created between the resin and the lead wire or a gap between the resin and the semiconductor element,
This is because moisture enters from the outside through the gap, and the Al wiring on the element, the bonding pad portion, etc. are easily corroded and easily broken.

Therefore, as measures against this, there have been proposed a method of increasing the adhesiveness with a resin by treating the element surface with a coupling agent, a method of sealing with a resin composition containing a coupling agent, and the like.

However, even with these methods, the moisture resistance of the resin-encapsulated semiconductor device has not been sufficiently improved.

In addition, in memory LSIs and the like, the trend toward higher density and higher integration has been remarkable, and the charge capacity of one cell has become smaller and smaller. Therefore, the α-ray energy generated from uranium and thorium contained in a small amount in the package material (for example, filler in the sealing resin composition) causes a defect in the operation of adjusting the charge capacity in the cell (soft Error) There is a problem.

As a countermeasure against this, a high-purity α-ray shielding material (for example, polyimide) is provided between the semiconductor element and the lead wire and the sealing material. However, the α-ray shielding material is inferior in adhesiveness and adhesiveness to a semiconductor element, and has not necessarily been effective in terms of the above-mentioned prevention of corrosion of Al wiring.

In addition, the multilayer wiring technology in the manufacture of semiconductor devices is becoming more and more important as the degree of integration is improved. The technical task is to form highly reliable wiring on various irregularities that appear on the surface as a semiconductor device is formed. Currently widely used method is vapor phase epitaxy (CV
In this method, an inorganic film according to the D method) or a film having a composite structure of an inorganic film that can be coated with a spinner and these films is used as an insulating film between wiring layers, and a conductive layer for wiring is formed in multiple layers.

By the way, in the vapor phase growth method, the unevenness of the surface of the film faithfully reflects the unevenness of the underlying layer, and the surface cannot be flattened.

The flattening of the surface not only prevents the conductor layer from breaking, but also
This is one of the most important techniques in the multi-layer wiring technique because it has the effect of preventing the reduction of the thickness of the conductor layer that occurs at the step portion, lowering the wiring resistance, and improving the processing accuracy of the wiring.

In the past, various methods have been proposed for achieving flattening. For example, Japanese Examined Patent Publication (Kokoku) No. 57-18343 discloses a method in which a part of the deposited conductor layer is used as an oxide as a part of an interlayer insulating film to suppress a step. As another example, as disclosed in Japanese Patent Laid-Open No. 56-76548, there is a method in which a low melting point glass is attached to the surface and heated to a temperature equal to or higher than the softening point to relax the inclination of the step portion. In addition to the method of forming an interlayer insulating film using the inorganic insulating film as described above, there is a method of forming an interlayer insulating film using an organic resin film. For example, polyimide is a typical example. Polyimide has very advantageous properties for forming multilayer wiring. However, as a fatal drawback, there is a drawback that it has high hygroscopicity and moisture permeability, like other organic resin films. In addition, there is a problem that the adhesiveness with the element constituent material is poor.

[Object of the Invention]

An object of the present invention is to provide a semiconductor device that can operate with high reliability even under high temperature and high humidity.

[Outline of Invention]

The present invention has been made in view of the above circumstances, and its gist is as follows.

1. At least the general formula on the semiconductor element and the lead wire [In the formula, Ar ₁ is (In the formula, x ₁ is nothing, -C (CH ₃ ) _2- , -COO-, Is one of the ), (In the formula, x ₁ is the same as above.). Also, Ar ₂ is (In the formula, x ₂ is nothing, -CH _2- , -C (CH ₃ ) _2- , -C (CF ₃ ) _2- , -CO-, -CO
O-,-S-,-SO _2- , Is one of the ). ] Acetylene group-terminated polyimide resin represented by the following, aromatic polyimide, polybenzimidazole, addition type polyimide, phenoxy resin, epoxy resin, phenol resin,
It has a coating obtained by coating it with a resin composition (A) containing at least one of a cyclohexane polymer and a fluorine-containing polymer and then curing it by heating, and then directly or indirectly on the surface of the coating. A semiconductor device characterized by being sealed with a resin composition (B) containing a filler.

2. The semiconductor device according to claim 1, wherein the resin composition (B) containing an inorganic filler contains at least one of a polyfunctional epoxy resin and an addition reaction type imide.

In the present invention, the general formula [In the formula, Ar ₁ is (In the formula, x ₁ is nothing, -C (CH ₃ ) _2- , -COO-, Is one of the ), (In the formula, x ₁ is the same as above.). Also, Ar ₂ is (In the formula, x ₂ is nothing, -CH _2- , -C (CH ₃ ) _2- , -C (CF ₃ ) _2- , -CO-, -CO
O-,-S-,-SO _2- , Is one of the ). ] The acetylene group-terminated polyimide resin represented by the following is obtained, for example, by the following reaction.

Among the acetylene group-terminated polyimide resins obtained by the above reaction, in particular, The acetylene group-terminated polyimide resin represented by the general formula [I] is used in a semiconductor device having a multilayer wiring structure.
It can be used as an insulating layer between layers, and in this case, the insulating layer can be flattened more than in the case where a conventional aromatic polyimide is used, and a more reliable multilayer structure can be realized.

Further, a known heterocyclic polymer can be used in combination with the resin composition of the present invention. For example, as the heterocyclic polymer, polyimide, polybenzimidazole, polybenzthiazole, polyoxadiazole, polypyrazole, polyquinoxaline, polythiazole, polytetraazopyrene, poly-4-phenyl-1,2,4-triazole. , Polyquinazolinedione, and polybenzoxazadisodione. Further, the skeleton of the above heterocyclic polymer may contain an amide bond, an ester bond, an ether bond, a sulfid bond, a sulfone bond, a urethane bond, a siloxane bond, or the like.

Among the above-mentioned heterocyclic polymers, particularly polymers having large solubility in a solvent in a ring-closed state, such as addition-type polyimides, are by-products associated with a reaction (for example, dehydration condensation reaction) during coating treatment on a semiconductor element. However, the stress on the surface of the element is reduced, which is preferable for suppressing the corrosion of Al wiring. As the addition type polyimide, for example, N,
Examples include N'-substituted bismaleimide compounds, and Diels-Alda adducts of the compounds.

The N, N′-substituted bismaleimide compound is, for example, [Wherein R represents an alkylene group, an arylene group or a substituted divalent organic group thereof], for example, N, N'-ethylene bismaleimide, N, N'-hexamethylene bismaleimide , N, N'-dodecamethylene bismaleimide, N, N'-m-phenylene bismaleimide, N, N'-4,4'-diphenyl ether bismaleimide, N, N'-4,4'-diff Phenylmethane bismaleimide,
N, N'-4,4'-dicyclohexylmethane bismaleimide, N, N'-4,4'-metaxylene bismaleimide, N,
N'-4,4'-diphenylcyclohexane bismaleimide
2,2-bis [4- (4-maleimidophenoxy) phenyl) propane, 2,2-bis [3-methyl-4- (4-maleimidophenoxy) phenyl] propane, 2,2-bis [ 3-chloro-4- (4-maleimidophenoxy) phenyl] propane, 2,2-bis [3-bromo-4- (4-
Maleimidophenoxy) phenyl] propane, 2,2-bis [3-ethyl-4- (4-maleimidophenoxy) phenyl] propane, 2,2-bis [3-propyl-4-]
(4-maleimidophenoxy) phenyl] propane, 2,
2-bis [3-isopropyl-4- (4-maleimidophenoxy) phenyl] propane, 2,2-bis [3-butyl-4- (4-maleimidophenoxy) phenyl] propane, 2,2- Bis (3-sec-butyl-4- (4-maleimidophenoxy) phenyl] propane, 2,2-bis [3
-Methoxy-4- (4-maleimidophenoxy) phenyl] propane, 1,1-bis [4- (4-maleimidophenoxy) phenyl] ethane, 1,1-bis [3-methyl-
4- (4-maleimidophenoxy) phenyl] ethane,
1,1-bis [3-chloro-4- (4-maleimidophenoxy) phenyl] ethane, 1,1-bis [3-bromo-4
-(4-maleimidophenoxy) phenyl] ethane, bis [4-4- (4-maleimidophenoxy) phenyl]
Methane, bis [3-methyl-4- (4-maleimidophenoxy) phenyl] methane, bis [3-chloro-4-
(4-maleimidophenoxy) phenyl] methane, bis [3-bromo-4- (4-maleimidophenoxy) phenyl] methane, 1,1,1,3,3,3-hexafluoro-2,2 -Bis [4- (4-maleimidophenoxy) phenyl] propane, 1,1,1,3,3,3-hexachloro-2,2-bis [4-
(4-maleimidophenoxy) phenyl] propane, 3,
3-bis [4- (4-maleimidophenoxy) phenyl] pentane, 1,1-bis [4- (4-maleimidophenoxy) phenyl] propane, 1,1,1,3,3,3- Hexafluoro-2,2-bis [3,5-dibromo-4- (4-maleimidophenoxy) phenyl] propane, 1,1,1,3,3,3-
Hexafluoro-2,2-bis [3-methyl-4- (4-
Maleimidophenoxy) phenyl] propane and the like, and one or more of them can be used. And the like, and two or more kinds of them may be mixed and used. Furthermore, a mixture of a mono-substituted maleimide, a tri-substituted maleimide, a tetra-substituted maleimide and the above-mentioned substituted bismaleimide can be appropriately used.

Further, an inorganic polymer or an inorganic filler can be added to the resin composition of the present invention.

The inorganic polymer means, for example, a polymer having a siloxane bond, a fluorine-containing polymer, a phosphazene polymer, a polymer having a carborane ring, and the like, and particularly, a polymer having a siloxane bond and a fluorine-containing polymer are , Effect of the present invention (in particular, improvement of adhesiveness between the semiconductor element surface and the resin composition)
It is effective in increasing the

As the inorganic filler, silica, alumina, titania, calcium carbonate, aluminum hydroxide, potassium titanate (fiber), aluminum silicate, zirconium silicate, zircon, glass, talc, clay, mica,
Powders of graphite, aluminum, copper, silver, iron, etc. One or more of these may be used in combination.

Further, a phenoxy resin can be added to the resin composition of the present invention. For example, The resin represented by Commercially available phenoxy resins include Aribadite from Ciba Products Co.
488E-32, Araldite 488N-40, Union Carbide Plastics
Co.'s PKHH, PKHA, PKHC, PAHJ, PKHS series, PRDA series, Dow Chemical Co.'s DER686MK40, DER684, MK40, Jone
s-Dabney Co. Epi-Rez 2287, Shell Chomical Co. Epon
ol53-L-32, Eponol53-40, Eponol55-L-32, Eponol55-B-40
and so on.

By adding the phenoxy resin, the adhesion between the surface of the device and the resin composition is improved.

Further, the resin composition of the present invention includes known surface treatment materials (coupling agents) such as silane-based, titanate-based, aluminum alcoholate-based, aluminum chelate-based, zirconate-based, borane-based, fluorine-based, and zircoaluminate-based materials. Can be used. For example, β- (3,4-Epoxy cyclohexyl) ethyl trimethoxy Silane, γ-Glycidoxy propyl trimethoxy Silane, N-β (aminoethyl) γ-aminopropyl methyl-dimethoxy Silane, γ-Chloropropyl-trimethoxy Silane, γ-Mercaptopropyl trimethoxy Silane, silane-based treatment agents such as γ-Aminopropyl triethoxy Silane, γ-Methacryloxy propyl trimethoxy Silane, γ-Ureidopropyl triethoxy Silane, methyl trimethoxy Silane, aluminum isopropylate, mono-Sec-butoxyaluminum diisopropylate, ethylacetoacetate aluminum diisopropylate, Aluminum tris (ethylacetoacetate), or tetraisopropyl titanate, tetranormal butyl titanate,
Tetrastearyl titanate, tetra-2-ethylhexyl titanate, titanium acetylacetonate, titanium triethanolaminate, titanium octylene glucolate, polyhydroxytitanium stearate, polyisopropoxytitanium stearate, or amino group terminal, carboxyl group There are zircoaluminate compounds having a terminal or a hydroxyl group terminal, and one or more kinds can be used in combination.

Examples of the encapsulating resin composition that can be used in the present invention include epoxy resin, phenol resin, melamine resin, urea resin, diallyl phthalate resin, unsaturated polyester resin, urethane resin, addition-type polyimide resin, silicone resin, Polyparavinylphenol resin,
Fluorocarbon resin, polyphenylene sulfide, polyamide,
Polyether, polyether ether ketone, polypropylene and the like.

Among these, the epoxy resin composition is useful as a sealing resin composition.

Examples of the epoxy resin include diglycidyl ether of bisphenol A, butadiene diepoxide, 3,4-
Epoxycyclohexylmethyl- (3,4-epoxy) cyclohexanecarboxylate, vinylcyclohexane dioxide, 4,4'-di (1,2-epoxyethyl) diphenyl ether, 4,4 '-(1,2-epoxyethyl) ) Biphenyl, 2,2-bis (3,4-epoxycyclohexyl) propane, glycidyl ether of resorcin, diglycidyl ether of phloroglysin, diglycidyl ether of methyl phloroglysin, bis- (2,3-epoxycyclopentyl) ether, 2- (3,4-epoxy) cyclohexane-5,5-spiro (3,4-epoxy) -cyclohexane-m-dioxane, bis (3,4-epoxy-6-methylcyclohexyl) adipate, N, N'- Bifunctional epoxide compounds such as m-phenylene bis (4,5-epoxy-1,2-cyclohexane) dicarboximide , Triglycidyl ether of para-aminophenol, polyallyl glycidyl ether, 1,3,5-tri (1,2-epoxy ethyl)
Trifunctional such as benzene, 2,2 ', 4,4'-tetraglycidoxybenzophenone, tetraglycidoxytetraphenylethane, phenolformaldehyde novolac polyglycidyl ether, glycerin triglycidyl ether, trimethylolpropane triglycidyl ether The above epoxy compounds are used.

As the curing agent, various phenol-based compounds and aldehyde-based compounds, resins produced by the addition condensation reaction in the presence of an acidic or basic catalyst are used, particularly phenol, cresol and the like and formaldehyde. A novolak resin synthesized by using an acid catalyzed reaction is useful.

Further, various catalysts can be added for the purpose of accelerating the curing reaction of the epoxy resin composition, and examples of the catalyst include triethanolamine, tetramethylbutanediamine, tetramethylpentanediamine, tetramethylhexanediamine, and triethylhexanediamine. Tertiary amines such as ethylenediamine and dimethylaniline, oxyalkylamines such as dimethylaminoethanol and dimethylaminopentanol, and aminos such as tris (dimethylaminomethyl) phenol and methylmorpholine can be applied.

Further, for the same purpose, as a catalyst, for example, cetyltrimethylammonium bromide, cetyltrimethylammonium chloride, dodecyltrimethylammonium iodide, trimethyldodecylammonium chloride,
Quaternary ammonium salts such as benzyl dimethyl tetradecyl ammonium chloride, benzyl methyl palmityl ammonium chloride, allyl dodecyl trimethyl ammonium bromide, benzyl dimethyl stearyl ammonium bromide, stearyl trimethyl ammonium chloride and benzyl dimethyl tetradecyl ammonium acetate can be applied Further, 2-undecylimidazole, 2-methylimidazole, 1-ethylimidazole, 2-heptadecylimidazole, 2-methyl-4-ethylimidazole, 1-
Butyl imidazole, 1-propyl-2-methyl imidazole, 1-benzyl-2-methyl imidazole, 1-
Imidazole compounds such as cyanoethyl-2-methylimidazole, 1-cyanoethyl-2-undecylimidazole, 1-cyanoethyl-2-phenylimidazole, 1-azine-2-methylimidazole and 1-azine-2-undecylimidazole, or Also, triphenylphosphine tetraphenylborate, triethylamine tetraphenylborate, N-methylmorpholine tetraphenylborate, viridine tetraphenylborate 2
Tetraphenylboron salts such as -ethyl-4-methylimidazole tetraphenylborate and 2-ethyl-1,4-dimethylimidazole tetraphenylborate are useful.

The above catalysts may be used in combination of two or more thereof, and the amount thereof may be used within the range of 0.01 to 20 in weight ratio with respect to 100 of the polyfunctional epoxy compound (A).

Further, the epoxy resin composition of the present invention, depending on its use and purpose of use, for example, calcium carbonate, silica, alumina, titania, aluminum hydroxide, aluminum silicate, zirconium silicate, zircon, glass, talc, mica. Powders of graphite, aluminum, copper, iron and short fibrous fillers, release agents such as fatty acids and waxes, epoxysilanes, vinylsilanes, coupling agents such as borane compounds and alkyl titanate compounds, and further antimony Flame retardants such as phosphorus compounds and halogen-containing compounds can be added.

Example of Invention

Example 1 250 ml of N-methylpyrrolidone was placed in a 500 ml Erlenmeyer flask, and the following three polyimide precursors were prepared. Was added with the predetermined amount shown in Table 1 and dissolved by heating and stirring to prepare a polyimide precursor solution.

Then, in the solution, phenoxy resin PKHH (manufactured by Union Carbide Co.), N, N'-4, as an addition type polyimide,
4'-diphenylmethane bismaleimide, (manufactured by Kawaken off Ain Chemical) aluminum chelate cutlet coupling agent ALCH-TR, a perfluoroalkyl acrylate _{CH 2 = CHCOO-C 2 H} 4 C 8 F 17 in Table 1, respectively A prescribed composition amount described above was added and dissolved to obtain a coating composition.

Then, the solution of the coating composition was dropped onto the element and the lead wire (including wire bonding) of the 256-kbit D-RAM memory LSI (16 pins). Then 1 at 100 ℃
Heating was continued for 2 hours at 200 ° C. for 1 hour and at 250 ° C. for 30 minutes to obtain a coating film having a thickness of 30 to 60 μm on the device.

Next, the memory LSI element coated with a composition containing at least a polyimide resin is encapsulated by transfer molding (molding at 180 ° C., 70 kg / cm ² , 1.5 minutes) with the epoxy resin composition described below, A sealed semiconductor device was obtained. Moisture resistance reliability was evaluated for 100 LSI chips. The results are shown in Table 1. For comparison, a resin composition containing no phenoxy resin is also shown in Table 1 as a comparative example.

Preparation of epoxy resin composition for encapsulation As a polyfunctional epoxy compound, tris (hydroxyphenyl) methane-based polyfunctional epoxy compound XD-9053
(Dow Chemical Co., epoxy equivalent 225) 100 parts by weight,
As a curing agent, 55 parts by weight of novolak type phenol resin (manufactured by Hitachi Chemical Co., softening point 83 ° C.), 3 parts by weight of triethylamine tetraphenyl borate (TEA-K) as a curing accelerator, and epoxysilane KBM303 as a coupling agent.
2 parts by weight (manufactured by Shin-Etsu Chemical Co., Ltd.), 5 parts by weight of addition type imide-coated red phosphorus as a flame retardant, 1 part by weight of calcium stearate and 1 part by weight of Hoechst wax E (manufactured by Hoechst Japan) as a release agent, 490 parts by weight of fused silica glass powder was added as a filler, and 2 parts by weight of carbon black (manufactured by KYABOT CORPORATION) was added as a colorant.

Then, the mixture was kneaded with a 2-inch roll having an 8-inch diameter at 70 to 85 ° C. for 7 minutes and then coarsely pulverized to obtain a resin composition.

Additional Examples Acetylene group-terminated polyimide (precursor) represented by the following formula The polymer was dissolved in toluene to prepare a 1% by weight resin solution. The element structure when the solution is used as a multilayer (two-layer) wiring insulating film is shown in FIGS. 1 and 2.

The structure of the element is as follows. After forming the SiO ₂ insulating layer, the polysilicon layer, and the first layer aluminum wiring (4-I) on the Si element substrate, apply the above resin coating material (using spinner) and bake. After (3-I) (250 ° C., 60 minutes), a positive resist was applied to pattern through holes. Then, plasma etching was performed using CF ₄ —O ₂ as a reaction gas. Then, the positive resist was removed by plasma etching using O ₃ as a reaction gas.

Next, after forming the second-layer aluminum wiring (4-II), the resin solution was further applied and baked (the same as the above conditions). (3-II Layer) FIG. 3 shows a case (4 layers) in which a polyimide resin was used as the coating resin for the second layer.

〔The invention's effect〕

According to the present invention, it is possible to provide a semiconductor device capable of highly reliable operation even under high temperature and high humidity.

[Brief description of drawings]

FIG. 1 is a sectional view of a semiconductor device according to an embodiment of the present invention, and FIGS. 2 and 3 are partial sectional views of element portions of a semiconductor device according to the present invention. 1 ... Lead wire, 2 ... Semiconductor element, 3 ... Protective coating resin, 3-I ... First layer protective coating resin, 3-II ... Second layer protective coating resin, 4-I ... First Layer wiring, 4-II ... Second
Layer wiring, 5 ... Polyimide resin, 6 ... Mold resin, 7 ... Thermosetting film.

 ─────────────────────────────────────────────────── ─── Continuation of front page (56) References Japanese Patent Publication No. 53-24053 (JP, B2) Japanese Patent Publication No. 58-11449 (JP, B2) Japanese Publication No. 53-6195 (JP, B2)

Claims (2)

[Claims] 1. A semiconductor device, a lead wire, and [In the formula, Ar ₁ is (In the formula, x ₁ is nothing, -C (CH ₃ ) _2- , -COO-, Is one of the ), (In the formula, x ₁ is the same as above.). Also, Ar ₂ is (In the formula, x ₂ is nothing, -CH _2- , -C (CH ₃ ) _2- , -C (CF ₃ ) _2- , -CO-, -CO
O-,-S-,-SO _2- , Is one of the ). ] And at least one of aromatic polyimide, polybenzimidazole, addition-type polyimide, phenoxy resin, epoxy resin, phenol resin, cyclohexane polymer, and fluorine-containing polymer After coating with the resin composition (A),
A semiconductor device having a coating film obtained by heating and curing, and then directly or indirectly sealing the surface of the coating film with a resin composition (B) containing an inorganic filler. 2. A resin composition (B) containing an inorganic filler,
At least one of polyfunctional epoxy resin and addition reaction type imide
The semiconductor device according to claim 1, further comprising a seed.