JPS62159436A - Semiconductor device - Google Patents

Abstract

PURPOSE:To obtain a semiconductor device having high reliability even at high temperature and high moisture by covering a semiconductor element and leads with a resin composition which contains acetylene group end polyimide resin. CONSTITUTION:After an SiO2 insulating layer, a polysilicon layer, and further first aluminum wirings (4-I) are formed on an Si element substrate, acetylene group end polyimide polymer is dissolved in a toluene, a coating material adjusted from 1wt% resin solution is covered and baked (3-I), a positive resist is then coated, and sulfone patterned. Then, a plasma etching with CF4-O2 as a reaction gas is executed. Thereafter, the positive resist is removed by a plasma asher with O2 as a reaction gas. Then, after second layer aluminum wirings (4-II) is formed, and the resin solution is further coated and baked.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a semiconductor device that can operate with high reliability even under high temperature and high humidity conditions, and a multilayer wiring structure of the semiconductor device.

[Background of the invention]

Conventionally, resin-sealed semiconductor devices have been exposed to high temperature and high humidity conditions (65-85C2) compared to ceramic-sealed semiconductor devices.
(95% relative humidity, 121C, 12 atmospheres supersaturated water vapor)
It was inferior in terms of operational reliability.

In a resin-sealed semiconductor device, a gap is created between the resin and the lead wire or at the interface between the resin and the semiconductor element.
This is because wiring, bonding bed parts, etc. are easily corroded and disconnected.

As a countermeasure against this problem, methods have been proposed, such as a method of treating the surface of the element with a coupling agent to increase its adhesion to the resin, and a method of sealing with a resin composition containing a coupling agent.

However, even with these methods, it has not been possible to sufficiently improve the moisture resistance of resin-sealed semiconductor devices.

Furthermore, in memory LSIs and the like, there has been a remarkable trend toward higher density and higher integration, and the charge capacity of one cell has become smaller and smaller. For this purpose, uranium contained in trace amounts in the pancage material (for example, fission in the sealing resin composition),
There is a problem in that α-ray energy generated from thorium causes defects in the adjustment operation of the charge capacity in the cell (ft error).

As a countermeasure against this problem, a high-purity α-ray shielding material (eg, polyimide, etc.) is provided between the semiconductor element and lead wires and the sealing material.

However, the α-ray shielding material has limited adhesion to semiconductor elements.

It has poor adhesion and is not necessarily effective in preventing corrosion of At wiring as mentioned above.

Furthermore, multilayer wiring technology in the manufacture of semiconductor devices is becoming increasingly important as the degree of integration increases. The technical challenge is to form highly reliable wiring on the various irregularities that appear on the surface as semiconductor devices are formed. The method currently widely used is the vapor phase growth method (C
In this method, a vaporized inorganic film (VD method) or a film with a composite structure of these films and an inorganic film that can be coated with a spinner is used as an insulating film between wiring layers, and a multilayer conductor layer for wiring is formed.

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

Flattening the surface not only prevents disconnection of the conductor layer, but also
Prevents thinning of the conductor layer that occurs at stepped portions and lowers wiring resistance.
It also has the effect of increasing wiring processing accuracy, and is one of the most important multilayer wiring technologies.

Various methods have been proposed to achieve flattening. For example, Japanese Patent Publication No. 57-18343 discloses a method of suppressing the occurrence of steps by making part of the attached conductor layer into an oxide and using it as part of an interlayer insulating film. Another example is JP-A-56-76
As seen in Japanese Patent No. 548, there is also a method of attaching low melting point glass to the surface and heating it to a temperature above the softening point to reduce the slope of the stepped portion. In addition to the method described above in which an inorganic insulating film is used as an interlayer insulating film, there is a method in which an organic resin film is used as an interlayer insulating film. A typical example is polyimide. Polyimide has very advantageous properties in forming multilayer wiring.

However, like other organic resin films, it has a fatal drawback of high hygroscopicity and moisture permeability. In addition, there is a problem of poor adhesion with element constituent materials.

[Purpose 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 conditions, and to provide a multilayer wiring structure for the semiconductor device.

[A essential point of the invention]

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

1. On the semiconductor element and lead wire, at least the general formula [In the formula, ArI is (In the formula, X is nothing, CH2, C(CHsh).

C(CFs)z, 0 +, co-, coo
, S.

You can choose one of the following. ), (wherein, X is the same as above). Further, Arz is one of the following (wherein, X is the same as above) (wherein, X is the same as above). It is characterized by being coated with a resin composition containing an acetylene group-terminated polyimide resin represented by the following formula.

2 The acetylene group-terminated polyimide resin has the general formula [wherein, Xl and Xi are absent or -〇+xl and X! may be the same or different.

Further, Ar2 is one of the following (where xl is either nothing, -0-1, or H3 and Fs). ] It is characterized by being a polyimide resin represented by the following.

1 At least on the semiconductor element and the lead wire, the general formula [wherein,
+-C(CFsh, 0, -CO-, Coo
, 8-.

CH.

It is one of the following. ), (wherein, X is the same as above). Moreover, Ar meaning is either (in the formula, X is the same as above) (in the formula, X is the same as above). It is characterized by being coated with a resin composition containing an acetylene group-terminated polyimide resin represented by the following formula and an inorganic polymer or an inorganic filler.

4. The inorganic polymer is a siloxane bond-containing polymer or a fluorine-based polymer.

& On the semiconductor element and the lead wire, at least the general formula [wherein Arl is
C(CFs)r-.

-O+, co, COO, S, Bo
x.

It is one of the following. ), (wherein, X is the same as above). Further, Ar2 is any one of (wherein, X is the same as above) (wherein, X is the same as above). ] is coated with an acetylene group-terminated polyimide resin, and then sealed with a resin composition containing an inorganic filler.

6. The resin composition containing an inorganic filler is characterized in that it contains at least a polyfunctional epoxy resin.

7. In a multilayer wiring structure of a semiconductor device consisting of an nth conductor layer, an insulating layer laminated on the nth conductor layer, and an (n+1)th conductor layer laminated on the insulating layer, There,
The insulating layer has the following general formula [I] [wherein, ArI is (in the formula, x is m+ CHh * CLCH3)2
*C(CFs)z, 0, CO, COO
,S.

It is one of Fs. ), (wherein, X is the same as above). Further, Ar2 is any one of (in the formula, X is the same as above) (in the formula, X is the same as above). ] It is characterized by being made of an acetylene group-terminated polyimide resin.

In the present invention, the general formula [wherein Ar1 is (wherein, X is nothing, CHs, C(CH3h
.

-C(CFsh, 0, CO+, -c
oo+, -s+.

It is one of the insteps. ), (wherein, X is the same as above). In addition, Ar is one of the following (in the formula, X is the same as above) (in the formula, X is the same as above). The acetylene group-terminated polyimide resin represented by ] can be obtained, for example, by the following reaction.

Among the acetylene group-terminated polyimide resins obtained by the above reaction, particularly the acetylene group-terminated polyimide resin [B] In addition, the resin composition of the present invention may be used in combination with a known heteroterminous polymer. You can also do it. For example, heterocyclic polymers include polyimide, polybenzimidazole, polybenzthiazole, polyoxadiazole, polypyrazole, polyquinoxaline, polythiazole, polytetraazopyrene, poly-4-phenyl-1,2,4-triazole. , polyquinazolinedione, polybenzooxadisodione, etc. Further, the skeleton of the heterocyclic polymer may contain an amide bond, an ester bond, an ether bond, a sulfide bond, a sulfone bond, a urethane bond, a siloxane bond, or the like.

Among the above-mentioned heteroterminous polymers, polymers with high solubility in solvents in a ring-closed state, such as addition type polyimides, are particularly susceptible to side effects accompanying reactions (e.g. dehydration condensation reactions) during coating processing on semiconductor devices. Since there are almost no living things and stress on the element surface is reduced, it is preferable for suppressing corrosion of At wiring.

Examples of addition type polyimides include N,N'-substituted bismaleimide compounds, and Diels-based compounds of the compounds.
There are alda adducts, etc.

A bismaleimide compound in which N, N'- is substituted is, for example, a compound represented by [in the formula, 几 represents an alkylene group, an arylene group, or a divalent organic group substituted therewith], for example, N, N'-substituted bismaleimide-based compounds. '-Ethylene bismaleimide, N, N'
- Hexamethine/bismaleimide, N,N'-dodecamethylene bismaleimide, N,N'-m-phenylene bismaleimide, N.

N'-4,4'-diphenyl ether bismaleimide,
N, N'-4,4'-diphenylmethane bismaleimide, N, N'-4,4'-dicyclohexylmethane bismaleimide, N, N'-4,4'-methaxylene bismaleimide)", N', N '-4゜4'-Diphenylcyclohexane bismaleimide 2.2-bis[4-(4-maleimidophenoxy)phenyl]propane, 2.2-bis[3-methyl-4-(4-ff leimidophenoxy)phenyl ] Propane, 2,2-bis[3-chloro-4-(
4-Maleimidophenoxy)phenyl]pronokun, 2
．． 2-bis[3-promo4-(4-maleimidophenoxy)phenyl]propane, 2,2-bis[3-ethyl-4-(4-maleimidophenoxy)phenyl]propa/, 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-(8)-butyl-4-←(4-maleimidophenoxy)phenyl]propane, 2゜2-bis[3
-methoxy-4-(4-maleimidophenoxy)phenyl]furopane, 1,1-bis[4-(4-maleimidophenoxy)phenyl]ethane, l,1-bis[3-methyl-4-(4-maleimidophenoxy) ) phenyl]ethane, 1゜1-bis[3-chloro-4-(4-maleimidophenoxy)phenyl]ethane, 1,1-bis[3-fromo4-(4-maleimidophenoxy)phenyl]ethane, bis[ 4-4-(4-maleimidophenoxy)phenylcomethane, bis(3-methyl-4-(4-maleimidophenoxy)phenylcomethane, bis[3-chloro-4-(4-maleimidophenoxy)phenylcomethane, Bis[3-promo 4-(4-maleimidophenoxy)phenylcomethane, 1,1,1,3.3.3-hexafluoro-2,2-bis(4-(4-maleimidophenoxy)phenyl]) Bread, l, 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 one or more of these can be used.

etc., and two or more of these can also be used in combination. Furthermore, monosubstituted maleimide,
A mixture of tri-substituted maleimide, tetra-substituted maleimide and the above-mentioned substituted bismaleimide can also be used as appropriate.

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

Inorganic polymers include, for example, polymers with siloxane bonds, fluorine-containing polymers, phosphazene polymers, polymers with carborane rings, etc. In particular, polymers with siloxane bonds and fluorine-containing polymers are Effects of the invention (especially improved adhesion between the semiconductor element surface and the resin composition)
It is effective in increasing the

Inorganic fillers include silica, alumina, titania, calcium carbonate, aluminum hydroxide, potassium titanate (fiber), aluminum silicate, zirconium silicate, zircon, and glass.

Talc, clay, mica, graphite, aluminum.

Powder of copper, silver, iron, etc. These L types or more can also be used in combination.

The resin composition of the present invention also includes phenoxy resin 'tl.
You can also add li. An example is a resin represented by the following formula. Commercially available phenoxy resins include Aral from C7ba products Co.
dite 488E-32, Araldite 488
N-40, [Jnion (::arbide pla
sticks Co, PKHH, PKHA, PKHC,
PAHJ, PKHS series.

PRDA series, ])ow Chemical
Co, glue, E, R686MK40, DER68
4, MK40. E of Jones-Dabney Co.
pi-Rez 2287.5hell Chomi-c
al Co, Eponol 53-L-32, Epo
no153-40゜Eponol 55-L-32, E
Examples include ponol 55-B-40.

By adding the phenoxy resin, it is possible to improve the adhesion between the element surface and the resin composition.

Further, the resin composition of the present invention includes silane-based, titanate-based, aluminum alcoholade-based, aluminum chelate-based, zirconate-based, and borane-based.

Known surface treatment agents (coupling agents) such as fluorine-based and zircoaluminate-based agents can be used. For example, β-(3,4-EpoxyIqyclohexyl)
ethyltrimethoxy 3i1ane.

1-Qlycidoxy propyl trimet
Hoxy 5ilane.

N-β(aminoethyl)r-aminopro
pyl methyl-dimethoxy 3i1a
ne.

r-Chloropropyl-trimethoxy
3i1ane.

r-Mercaptopropyl trimetho
xy 3i1ane.

r-Aminopropyl triethoxy
3i1ane.

1-Methacryloxy propyl tr
imethoxy 5ilane.

r-Ureidopropyl triethoxy
5ilane.

Silane treatment agents such as methyl trimethoxy 5ilane, aluminum isopropylate,
Mono-8ec-butoxyaluminum diisopropylate.

Ethyl acetoacetate aluminum diisopropylate, aluminum tris(ethyl acetoacetate),
Alternatively, tetra-ingrovir titanate, tetra-n-butyl titanate, tetrastearyl titanate,
Tetra-2-ethylhexyl titanate, titanium acetylacetonate.

Titanium triethanolaminate, titanium octylene glycolate, polyhydroxytitanium stearate, polyisopropoxytitanium stearate, or zircoaluminate compounds with amino, carboxyl, or hydroxyl terminals, etc. One or more types can also be used in combination.

Examples of the sealing 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,
Fluororesin, polyphenylene sulfide, polyamide,
Examples include polyether, polyetheretherketone, and polypropylene.

Among these, epoxy resin compositions are useful as sealing resin compositions.

Examples of the epoxy resin include diglycidyl ether of bisphenol A, butadiene dieboxide, 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 resorci/, diglycidyl ether of 70 loglycine, diglycidyl ether of methyl 70 loglycine, bis-(
2,3-epoxycyclobentyl)ether, 2-(3
,4-epoxy)cyclohexane-5,5-spiro(3
,4-epoxy)-cyclohexane-m-dioxane,
Bis-(3,4-evoxy-6-methylcyclohexyl)adipate, N,N'-m-phenylenebis(4,5
- Difunctional epoxy compounds such as dicarboximide (epoxy-1,2-cyclohexane), triglycidyl ether of mono-aminophenol, polyallyl glycidyl ether, 1,3.5-1(1,2-epoxyethyl ) Benzene, 2.2'.

4. Tri- or higher functional epoxy compounds such as 4'-tetraglycidoxybenzophenone, tetraglycidoxytetraphenylethane, polyglycidyl ether of phenol formaldehyde novolac, triglycidyl ether of glycerin, triglycidyl ether of trimethylolpropane, etc. used.

As the curing agent, resins produced by addition condensation reaction of various phenolic compounds and aldehyde compounds in the presence of an acidic or basic catalyst are used. Novolak resins synthesized by acidic catalytic reactions are useful.

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

For the same purpose, catalysts such as cetyltrimethylammonium bromide, cetyltrimethylammonium chloride, dodecyltrimethylammonium iodide, trimethyldodecylammonium chloride,
Benzyldimethyltetradecylammonium chloride, penzylmethylpalmitylammonium chloride,
Quaternary ammonium salts such as allyldodecyltrimethylammonium bromide, benzyldimethylstearylammonium bromide, stearyltrimethylammonium chloride and benzyldimethyltetradecylammonium acetate can be applied;
-undecylimidazole, 2-methylimidazole,
1-ethylimidazole, 2-heptatecylimidazole, 2-methyl-4-ethylimidazole, 1-butylimidazole, 1-propyl-2-methylimidazole, 1-benzyl-2-methylimidazole, 1-cyanoethyl-2 -Methylimidazole, 1-cyanoethyl-
2-undecylimidazole, 1-cyanoethyl-2-
Imidazole compounds such as phenylimidazole, 1-azine-2-methylimidazole and 1-azine-2-undecylimidazole, or triphenylphosphine tetraphenylborate, triethylamine tetraphenylborate, N-methylmorpholine tetraphenylborate, Tetraphenylphorone salts such as pyridine tetraphenylborate, 2-ethyl-4-methylimidazole tetraphenylborate, and 2-ethyl-1,4-dimethylimidazole tetraphenylborate are useful.

The above catalysts can also be used in combination of two or more, and the amount thereof is determined by the amount of polyfunctional epoxy compound (relative to 100 Al).
It may be used in a weight ratio of 0.01 to 20.

In addition, the uninvented epoxy resin composition may include, for example, calcium carbonate, silica, alumina, titania, aluminum hydroxide, aluminum silicate, zirconium silicate, zircon, glass, Merck, mica, etc., depending on its use and purpose. , powders and short fibrous fillers such as graphite, aluminum, copper, and iron, mold release agents such as fatty acids and waxes, coupling agents such as epoxy silane, vinyl silane, borane compounds, and alkyl titanate compounds, and further, Flame retardants such as antimony and phosphorus compounds and halogen-containing compounds can be added.

[Embodiments of the invention]

Example 1 25011 J of hemomethylhydrolidone was placed in a 500 d Erlenmeyer flask, and the following three types of polyimide precursor polyimide [C] were added in the predetermined amounts described in Section 1, and the mixture was heated and stirred. to prepare a polyimide precursor solution.

Then, phenoxy 41111 PKHH (
(manufactured by Union Carbide), addition type polyimide, N,N'-4,4'-diphenylmethane bismaleimide, aluminum chelate coupling agent ALC) (
-TR (manufactured by Yoken Fine Chemical Co., Ltd.), perfluoroalkyl acrylate CH, and =CHC00-C snow HaCsF+y were added in nine predetermined amounts shown in Table 1 and dissolved to obtain a memorization composition.

Next, a pit D-RAM memory LSI (1
The solution of the above coating composition was dropped onto the device (6 pins) and lead wires (including wire bonding). After that, 1 hour at 100t:', 1 hour at 200C, 250C
Heating was continued for 30 minutes to obtain a coating film with 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 was subjected to transfer molding (1801,', 70k) using the following Evokin resin composition.
19/7.1.5 minute molding) to obtain a resin-sealed semiconductor device. Moisture resistance reliability was evaluated for each of 100 LSIs.

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.

Creation of epoxy resin composition for sealing Tris(hydroxyphenyl)methane-based polyfunctional epoxy compound XD-90 as a polyfunctional epoxy compound
53 (manufactured by Dow Chemical Company, epoxy resin - Ji2251
100 parts by weight as a curing agent, 55 parts by weight of novolac type phenol resin (manufactured by Hitachi Chemical Co., Ltd., softening point 83C), 3 parts by weight of triethylaminetetraphenylvolley (TEA-K) as a curing accelerator, 3 parts by weight of triethylaminetetraphenylvolley (TEA-K) as a coupling agent,
2 parts by weight of epoxy silane KBM303 (manufactured by Shin-Etsu Chemical Co., Ltd.), 5 parts by weight of addition-type imide coated red phosphorus as a flame retardant,
As a mold release agent, 1 part by weight of calcium stearate and 1 part by weight of Hoechst Wax RJ (manufactured by Hoechst Japan),
490 parts by weight of fused silica glass powder was added as a filler, and 2 parts by weight of carbon black (manufactured by Cabot) were added as a colorant.

Next, the mixture was kneaded for 7 minutes using two 70-85C rolls with an 8-inch diameter, and then coarsely ground to obtain a resin composition.

An additional embodiment is expressed by the following formula. Acetylene group-terminated polyimide (precursor) A 1% by weight resin solution was prepared by dissolving the polymer in toluene. The device structure when this solution is used as a multilayer (two-layer) wiring insulating film is shown in FIGS. 1 and 2.

The device consists of a Si device substrate, an SiO2 insulating layer, a polysilicon layer, and a first layer of aluminum wiring (4-
After forming 11, the above resin coating material was applied (using a spinner) and baked (250C for 160 minutes) (3-
After 11 days, a positive resist was applied and the through holes were patterned. Next, plasma etching was performed using CF402 as a reactive gas. Next, the positive resist was removed using a plasma asher using 03 as a reactive gas.

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

〔Effect of the invention〕

According to the present invention, it is possible to provide a semiconductor device that can operate with high reliability even under high temperature and high humidity conditions.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view of a semiconductor device according to an embodiment of the present invention, and FIGS. 2 and 3 are partial cross-sectional views of an element portion of the semiconductor device according to the present invention. DESCRIPTION OF SYMBOLS 1... Lead wire, 2... Semiconductor element, 3... Protective coating resin, 3-1... First layer protection coating resin, 3-11
...Second layer protective coating resin, 4-1...First layer wiring,
4-■...Second layer wiring, 5...Polyimide resin,
6...Mold resin, 7...Thermosetting film.

Claims (1)

[Claims] 1. On the semiconductor element and lead wire, at least there is a general formula ▲ a mathematical formula, a chemical formula, a table, etc. ▼ [I] [In the formula, Ar_1 is ▲ a mathematical formula, a chemical formula, a table, etc. ▼, ▲ mathematical formulas, chemical formulas,
There are tables, etc. ▼ (In the formula, x is nothing, -CH_2-, -C(CH_3)_2
-, -C(CF_3)_2-, -O-, -CO-, -C
It is one of the following: OO-, -S-, -SO_2-, ▲There are mathematical formulas, chemical formulas, tables, etc.▼, ▲There are mathematical formulas, chemical formulas, tables, etc.▼. ), ▲There are mathematical formulas, chemical formulas, tables, etc.▼ (In the formula, x is the same as above.) Also, Ar_2 has ▲mathematical formulas, chemical formulas, tables, etc.▼, ▲mathematical formulas, chemical formulas,
There are tables, etc.▼ (In the formula, x is the same as above.) ▲There are mathematical formulas, chemical formulas, tables, etc.▼ (In the formula, x is the same as above.) ] A semiconductor device coated with a resin composition containing an acetylene group-terminated polyimide resin.