JPS60177659A - Manufacture of semiconductor device - Google Patents

Abstract

PURPOSE:To obtain a device with high reliability, by a method wherein the device is covered with resin which is the product by the reaction of organic compounds which are indicated in prescribed general formulas respectively. CONSTITUTION:99-80mol% of tetracarboxylic acid dianhydride A and 1-20mol% of tetracarboxylic acid dianhydride B which are indicated in prescribed formulas I and IIrespectively, and 99-60mol% of diamine C and 1-40mol% of diamine D which are indicated in formulas III and IV, are reacted in a organic polar liquid solution in an inert gas at the anhyride codition at the temperature 0-100 deg.C. An element A hightens the starting temperature of heat decomposition temperature, elements B-D highten the rigidity of resin, and an element C hightens the starting temprature of decomposition as much of its quantity. The intrinsic viscosity of the obtained polyamic acid product is 0.5-2.5 and the heat decomposition temperature of the hardened material after imidefy is 480-580 deg.C. When a semiconductor element is covered with this high temperature resin and heated and hardened, there will be no deterioration of films and generation of cracked gas, and a semiconductor of high reliability can be obtained. Still more, it may be suitable to use pyromellitic dianhydride for A: benzophenonetetracarboxylic dianhydride for B: paraphenylene diamine for C, and 4,4'-diaminophenyl ether for D.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing a semiconductor device using a heat-resistant resin made from tetracarboxylic dianhydride and diamine.

The purpose of this is to coat the surface of a semiconductor element with a heat-resistant resin whose cured resin, which has been imidized through a ring-closing process and has a significantly high thermal decomposition onset temperature, is exposed to high temperatures, high humidity, and It is an object of the present invention to provide a highly reliable semiconductor device that is protected from high bias and further protected from radiation such as alpha rays.

Conventionally, diamines containing at least two carbon atoms are
A tetravalent group containing a tetravalent group containing at least two carbon atoms, and in which at most two of the carbonyl groups of the dianhydride group are bonded to any one of the carbon atoms of the tetravalent group. cypolyimides by reacting with a carboxylic dianhydride, thereby forming a cybolyamic acid product, which is then heated to a temperature above 50° C. to convert the polyamic acid product to polyimide. It is well known that the production of The produced polyimides are characterized in that they have repeating units consisting of diamine and tetracarboxylic dianhydride groups, and furthermore, the diamine group has a divalent group containing at least two carbon atoms. and once the tetracarboxylic dianhydride group contains a divalent group containing at least 2 carbon atoms, at most two of the carbonyl groups of the dianhydride group are carbon atoms of the tetravalent group. It is also known that it is characterized by being bonded to any one of the atoms. Furthermore, as the tetracarboxylic dianhydride, pyromellitic dianhydride, benzophenonetetracarboxylic dianhydride, 2,3゜6.7-naphthalenetetracarboxylic dianhydride, 3゜314.4'- Diphenyltetracarboxylic dianhydride, 1.2,5.6-naphthalenetetracarboxylic dianhydride, 2,2'13.3'-diphenyltetracarboxylic dianhydride, 2.2-bis(3
,4-dicarboxydiphenyl)propane dianhydride, 3
．． 4.9.10-perylenetetracarboxylic dianhydride,
Bis(3,4-dicarboxydiphenyl)ether dianhydride, ethylenetetracarboxylic dianhydride, naphthalene-L2+4+5-tetracarboxylic dianhydride, naphthalene-1,4,5,8-tetracarboxylic dianhydride, Decahydronaphthalene-1,4,518-tetracarboxylic dianhydride, 4I8-dimethyl-1,213151617
-Hexahytronaphthalene-1.2,5.6-tetracarboxylic dianhydride, 2,6-cyclonaphthalene-1.
4,518-Tetracarboxylic dianhydride, 2.7-cyclonaphthalene-1,4゜5.8-tetracarboxylic dianhydride, 2.3.4.7-titrachloronaphthalene-1
．． 4,5.8-tetracarboxylic dianhydride, phenanthrene-1,8,9,10-tetracarboxylic dianhydride,
Cyclopentane-1,2,3゜4-tetracarboxylic dianhydride, pyrrolidine-2゜3,4,5-tetracarboxylic dianhydride, pyrazine-2,3,5,6-tetracarboxylic dianhydride 2,2-bis(2,5-dicarboxyphenyl)propane dianhydride, 1,1-bis(2,3-dicarboxyphenyl)ethane dianhydride, 1,1-bis(
3,4-dicarboxyphenyl)ethane dianhydride, bis(2,3-dicarboxyphenyl)ethane dianhydride, bis(3,4-dicarboxyphenyl)methane dianhydride,
Bis(3,4-dicarboxyphenyl)sulfone dianhydride, benzene-1,2,3,4-tetracarboxylic dianhydride, 1,213.4-butanetetracarboxylic dianhydride, thiophene-2,3 , 4,5-tetracarboxylic dianhydride, etc., and diamines such as m-phenylenediamine, p-phenylenediamine, 4°4'-diaminodiphenylpropane, 4,4'-diaminodiphenylmethane, benzidine, 4. 4'-diaminodiphenylsulfide, 4.4'-diaminodiphenylsulfone, '3.3'-diaminodiphenylsulfone, 4.4
'-diaminodiphenyl ether, 2,6-diamitubiridine, bis(4-aminophenyl)phosphine oxyto, bis(4-7minophenyl)-N-methylamine,
1,5-diaminonaphthalene, 3,3'-dimethyl-4
, 4'-diaminobiphenyl, 313'-dimethoxybenzidine, 2,4-bis(β-amino-t-butyl)toluene, bis(p-β-amino-t-butylphenyl)
Ether, p-bis(2-methyl-4-aminopentyl)benzene, p-bis(1,1-dimethyl-5-aminopentyl)benzene, m-xylylenediamine, p-xylylenediamine, bis(p- aminocyclohexyl)
Methane, ethylenediamine, propylene diamine, hexamethylene diamine, heptamethylene diamine, octamethylene diamine, nonamethylene diamine, decamethylene diamine, 3-methylhebutamethylene diamine, 4.
4-dimethylhebutamethylenediamine, 2,11-diaminododecane, 1,2-bis(3-aminopropoxy)
Ethane, 2I2-dimethylpropylenediamine, 3-methoxyhexamethylenediamine, 2,5-dimethylhexamethylenediamine, 5-methylnonamethylenediamine, 1I4-diaminocyclohexane, 1,12-diaminooctadecane, 2,5-diamino- The use of 1,3,4-oxadiazole, etc. has also already been carried out.

These polyimide resins are coated on the surface of semiconductor elements,
It is known that it is effective in improving the page print characteristics and preventing alpha radiation resistance.

The main reasons why highly heat-resistant resins such as polyimide resins are necessary for semiconductor surface coatings are as follows.

(a) Semiconductor elements are extremely sensitive to external temperatures, and their quality deteriorates significantly when exposed to high temperatures. For this reason, the element surface is covered with polyimide resin, which has excellent heat resistance, for heat-resistant protection. In other words, it is said to be essential for improving the characteristics of PADGE PAGE 1.

←) Also, when a semiconductor element is used as a super LSI (RAM or higher), the super LSI is protected against alpha rays generated from natural substances contained in the seven-layer material or ceramic lid that seals the chip. Since malfunctions are likely to occur, methods are used to protect the surface by coating it with polyimide resin. In this case as well, particularly when sealing with a ceramic lid (hermetic sealing), a polyimide resin that can withstand high temperatures of 480 to 500°C is required.

(c) Furthermore, in order to make the process of forming memory and circuits on the surface of a semiconductor element and mounting an IC more compact, multilayer wiring on the surface has been implemented. Polyimide resin is used for the insulating film at this time, but in this case as well, the annealing temperature after aluminum vapor deposition of the electrode (450 to 5
00°C).

As described above, polyimide resin, which is highly heat resistant, is used as an important material to protect the surface of semiconductor elements and maintain quality.

However, the current performance is far from satisfactory, and the quality of the element cannot be maintained sufficiently due to insufficient heat resistance, resulting in some reductions in reliability.

This is because the thermal decomposition onset temperature of current polyimide resins is approximately 4
At 50°C, the required heat resistance of (a), (b), and (c) described above is also lower. As a result, due to the deterioration of the characteristics of the film and the generation of decomposed gas, the reliability as a semiconductor device is degraded as well as the original performance when used.

In view of this current situation, the present inventors have developed a polyimide resin with a thermal decomposition starting temperature of 480°C while maintaining its excellent properties.
As a result of intensive research with the aim of improving the temperature to above -CO-1-Ko, -5O2-1-S-1-CI
(Tetracarboxylic dianhydride [F] represented by 2-1CH3CF3) 1-2
Tetracarboxylic acid dianhydride consisting of 0 molti and diamine (2) represented by the general formula H2N-R2-Nl2 (R1 is a benzene ring, fused benzene ring) (099-60 molti and HCF3) Under anhydrous conditions, in an inert gas atmosphere, in an organic polar solvent, the polyamic acid product is reacted with a diamine consisting of 40 mol. The inventors discovered the surprising fact that a highly heat-resistant polyimide resin having a thermal decomposition initiation temperature of 480 to 580 DEG C. can be obtained by adjusting the temperature to 25, and completed the present invention using this resin.

In other words, the feature of the present invention is that, as a result of a detailed study of various factors that affect the thermal decomposition initiation temperature, the new finding that the degree of polymerization of the resin as well as the resin structure has a significantly large influence has been obtained. . Various efforts have been made to improve heat resistance. That is, the first method is to increase the stability of the bonds contained in the resin, or in other words, the energy of the bonds as much as possible. The heat resistance of aliphatic chain resins consisting only of single bonds is extremely poor. This means that the bond energy of a single bond is, for example, C-C (80kcat/mot
), CN (62kcit/mot), which is small. On the other hand, the bond energies of double bonds and triple bonds are, for example, C=C (142kcal/mot), C=C
(186kcat/mot), C=N (121kc
at/mot), C”=N (191kcat/
mot) and much thicker. Therefore, in order to improve heat resistance, it is necessary to introduce multiple bonds, aromatic rings, etc. into the main chain of the resin. Since aromatic rings and heterocycles are multistabilized by resonance, they are considered to be advantageous in further improving heat resistance.

The second method is to increase the melting point and glass transition point by introducing an aromatic ring with good symmetry into the main chain of the resin. Generally, there is a relationship of Tm=A)ImΔSm between the melting point (hereinafter referred to as Tm), the enthalpy of melting (hereinafter referred to as Heke), and the entropy of melting (hereinafter referred to as ΔSm). Here, Δb is a quantity related to intermolecular force, and 68m is a quantity mainly related to the flexibility and symmetry of molecules. 'Bang is often greatly influenced by 68m,
It is known that the more para-bonded aromatic rings there are in the main chain of the resin, the smaller 68m becomes and the higher j>Tm becomes. That is, in order to improve heat resistance, it is necessary to introduce an aromatic ring with good symmetry.

In this way, the theory for improving heat resistance has been completed, and the molecular structure of heat-resistant resins has been designed based on this theory.
The main focus of research was on the temperatures at which decomposition occurs violently.

In the present invention, the problem is not the thermal decomposition temperature but the thermal decomposition initiation temperature.

Until now, there has been no comprehensive research on this subject.

As a result of a detailed study of the thermal decomposition temperature and the thermal decomposition start temperature, the present inventors obtained the knowledge that a material having a high thermal decomposition temperature does not necessarily have a high thermal decomposition start temperature. Of course, in order to improve heat resistance, molecular design based on theory is fundamental, and it is clear that the molecular structure has the greatest effect, but on top of that, the degree of resin polymerization is a significant factor that affects the thermal decomposition initiation temperature. I discovered something big. That is, resin polymerization degree is small #1
This is a surprising finding that the temperature at which thermal decomposition begins is high.

In general, the higher the resin polymerization degree, the higher the thermal decomposition temperature, and this is also theoretically clear. However, it was not known until now that the temperature at which thermal decomposition begins decreases.

The thermal decomposition initiation temperature referred to herein refers to the temperature at which the loss of shrinkage due to heating begins as measured by differential thermal balance analysis. The reason why the thermal decomposition onset temperature is lower is not clear, but in addition to the original thermal decomposition in which single bonds are broken even in side chain functional groups or the main chain, which have weak binding energy due to the molecular structure, polyamic acid can be heated, etc. In resins with a high degree of polymerization, volatile components such as water, unreacted raw materials, and residual solvents generated during ring-closing treatment cannot be volatilized due to the high melt viscosity and are trapped in the cured resin. It is thought that this may be because they are exposed. The degree of resin polymerization is mainly determined by the charged molar ratio of the raw materials tetracarboxylic dianhydride and diamine, and the molar ratio approaches 1 and increases to 1, but even if the molar ratio is constant, the reaction conditions such as Raw material purity, moisture content,
It is also possible to change the reaction temperature, reaction time, amount of reaction terminator, reaction solvent system, etc.

The method of the present invention is a tetracarboxylic dianhydride represented by 0 (R1 is a benzene ring, a fused benzene ring) and 0 (X, (button, -needle, -5o2-1-s-1). -CH2-
A tetracarboxylic dianhydride represented by 1 and a general formula H
2N-R2-NH.

(R1 is a benzene ring, fused benzene ring) (x2 bar co
A diamine consisting of 1 to 40 moles of diamine ([)) represented by -1-needle, -5O2-1-S-1-CH2-1, and an organic polar Heat resistance: the intrinsic viscosity of the polyamic acid product reacted in a solvent at 0 to 100°C is 0.5 to 2.5, and the thermal decomposition initiation temperature of the cured product after imidization is 480 to 580°C. This method of manufacturing a semiconductor device is characterized in that a resin is applied to the semiconductor element surface m1, heated and cured, and adhered to the semiconductor element surface.

The tetracarboxylic dianhydride prisoner in the present invention has the effect of increasing the thermal decomposition initiation temperature.

Of these, those in which R1 is a benzene ring or a condensed benzene ring are highly effective, and among these, pyromellitic dianhydride is particularly excellent. When the proportion of tetracarboxylic dianhydride (2) in the tetracarboxylic dianhydride component in the resin is high, the thermal decomposition initiation temperature becomes high, but the resin becomes rigid.

The tetracarboxylic dianhydride (@) in the present invention has the effect of improving the rigidity of the resin.

This compound has excellent flexibility due to the single bond in the main chain sandwiching xl that connects the aromatic rings.As Ox1, -C
O-1-can, -SO□-1-S-1-CI (2-1H3
CF3 benzophenone tetracarboxylic dianhydride is excellent. The higher the proportion of tetracarboxylic dianhydride [F]) in the tetracarboxylic dianhydride component in the resin, the better the rigidity will be, but the target thermal decomposition initiation temperature will be lower. Tetracarbo/112 dianhydride (B) 1120 mol% or more for dianhydride (2)
Must be less than mulch.

The diamine (C) in the present invention has the effect of increasing the thermal decomposition initiation temperature.

Among the compounds represented by the general formula H2N-R2-Nl2, those in which R2 is a benzene ring or a condensed benzene ring are most effective, and among these, paraphenylenediamine is particularly excellent. Diamine (Q
#1, which has a high ratio of , has a high thermal decomposition temperature, but the resin becomes more rigid.

The diamine (2) in the present invention has the effect of improving the rigidity of the resin.

It has excellent flexibility.

X2 and i H-CO-1-needle, -5o2-1-s-1
-CH2-1H2CF3 4T4'-sialenodiphenyl ether is excellent.

The higher the proportion of diamine (6) in the diamine component in the resin, the better the rigidity will be, but the target thermal decomposition initiation temperature will be lower. Must be less than 40 molt.

The solvent of the reaction system in the present invention is an organic polar solvent whose functional group has a dipole moment that does not react with the tetracarboxylic dianhydride or diamines. In addition to being inert to the system and being a solvent to the product,
The organic polar solvent must be solvent for at least one, preferably both, of the reaction components. Typical solvents of this type are N,N-dimethylpolamide, N,N-dimethylacetamide, N,N-diethylformamide, N,N-diethylacetamide, N,N
-Dimethylmethoxyacetamide, dimethylsulfoxide, hexamethylphosphoamide, N-methyl-2-pyrrolidone, pyridine, dimethylsulfone, tetramethylenesulfone, dimethyltetramethylenesulfone, etc.These solvents may be used alone or in combination. Ru.

In addition, benzene, benzonitrile, dioxa/butyrolactone, xylene, toluene, and cyclohexane are used in combination as solvents. It is used as a coating agent, film smoothing agent, etc.

4. It is generally preferable to carry out the present invention under neutral conditions. This is because the tetracarboxylic dianhydride may be ring-opened by water, becoming inactivated, and stopping the reaction. For this reason, it is necessary to remove both the moisture in the raw materials and the moisture in the solvent. However, in order to adjust the progress of the reaction and control the degree of resin polymerization, water is sometimes intentionally added. Further, the present invention is preferably carried out in an inert gas atmosphere. This is to prevent oxidation of diamines. Dry nitrogen gas is generally used as the inert gas.

The reaction of the heat-resistant resin in the present invention can be carried out in the following various ways.

(2) Diamines and tetracarboxylic dianhydride are mixed in advance, and the mixture is added little by little into an organic solvent while stirring. This method is relatively advantageous in exothermic reactions such as those for polyimide resins.

(2) Conversely, there is also a method of adding a solvent to a mixture of diamines and tetracarboxylic dianhydride while stirring.

(2) A commonly used method is to dissolve only diamines in a solvent, and then add tetracarboxylic dianhydride to the solution in a proportion that allows control of the reaction rate.

■It is also possible to dissolve diamines and tetracarboxylic dianhydride separately in a solvent and then slowly add the two solutions in a reactor.

(2) Furthermore, it is also possible to prepare in advance a polyamic acid product containing an excess of diamines and a polyamic acid product containing an excess of tetracarboxylic dianhydride, and then further react them in a reactor.

The reaction temperature is preferably 0 to 100°C. This is because if the temperature is below 0°C, the reaction rate is slow, and if it is above 100°C, the produced polyamic acid gradually starts the ring-closing reaction. Usually, the reaction is carried out at around 20° C., and since it is an exothermic reaction, cooling is required. The degree of polymerization of boriamic acid can be controlled in a planned manner. When the tetracarboxylic dianhydride and diamine are close to equimolar in mole #1, the degree of polymerization increases. When the amount of either raw material increases by 5% or more, the degree of polymerization decreases significantly. Generally, it is common practice to use 1 to 3% more of one raw material in terms of workability and processability. In order to control the degree of polymerization, it is also possible to end-block with phthalic anhydride or aniline, or add water to ring-open one of the acid anhydride groups to inactivate it.

The intrinsic viscosity of the polyamic acid product in the present invention is 0.
5-25 is preferred. If it is lower than 0.5, it is good for improving the thermal decomposition start temperature, but the thermal decomposition temperature is too low and the film forming property is also lowered. If it is higher than 2.5, the film forming property will be excellent, but the temperature at which thermal decomposition starts will be lowered.

When used, the polyamic acid product produced by the method of the present invention can be used with various silane coupling agents, borane coupling agents, titanate coupling agents, aluminum coupling agents, and other chelate-based adhesives. Properties improvers, various solvents, and flow agents may be added, and in addition to these, small amounts of ordinary acid curing agents, amine curing agents, polyamide curing agents, and curing accelerators such as imidazole and tertiary amines may be added. Also, flexibility additives and viscosity modifiers such as polysulfide, polyester, low molecular weight epoxy, talc, clay, mica, feldspar powder,
Small amounts of fillers such as quartz powder and magnesium oxide, colorants such as carbon black and ferrocyanine flue, flame retardants such as tetrabromophenylmethane and tributyl phosphate, and flame retardant aids such as antimony trioxide and barium metafoate. These additions open up many uses. The method for manufacturing a semiconductor device using this heat-resistant resin is to dissolve the resin composition in a solvent, mix it uniformly, make a concentration of 5 to 55%, and then wire the resin composition on a semiconductor substrate or an insulator substrate. It is cast onto the surface of the conductor layer and coated to a uniform thickness in the range of 0.1 to 500μ, then heated in a dryer at a temperature of 50 to 500℃ in two or more steps as necessary. Dry for 5 minutes to 30 hours to form a resin film. Equipment for casting the resin includes wheelers, spinners, roll coaters,
Use a doctor blade, Gisa, flow coater, etc. For drying, electric heat, infrared rays, steam, high frequency, a combination thereof, etc. are used.

A polyimide resin film formed on a semiconductor element may be partially etched depending on the method of use.

The main reason is the opening in the bonding butt portion or the conduction between the eyebrows of the multilayer wiring.

Typical etching methods include ashing with plasma in the case of a dry method, and use of a strong alkali such as hydrazine or tetramethylammonium hydroxide as an etching solution in the case of a wet method.

In the method of the present invention, in order to further improve the adhesion between the resin coating film and the substrate, it is even more effective to undercoat the surface treatment agent on the substrate. This is particularly effective for circuit boards with silicone substrates or gold plating, which usually have poor adhesion.

Although it is effective to use ordinary silane coupling agents and borane coupling agents as surface treatment agents, silane coupling agents are particularly effective for coating films obtained from the resin used in the present invention. Silane coupling agents include vinyl silanes, aminosilanes, epoxysilanes, etc. Among them, when aminosilanes are interposed between the coating film made of the resin used in the present invention and the silicone substrate, a very additive effect occurs, which is noticeable. Improves adhesion. As an aminosilane coupling agent, n-β-(aminoethyl)
γ-aminopropylmethoxysilane, n-β(aminoethyl)γ-aminopropylmethyldimethoxysilane, n
-Phenyl γ-aminopropyltrimethoxysilane, γ
-aminopropyltrimethoxysilane, etc.

The present invention is mainly used as a coating film for protecting the surfaces of various semiconductor elements, and as a heat-resistant and moisture-resistant insulating film for forming multilayer wiring thereon. For example, semiconductors, transistors, linear ICs, hybrid I
C, light emitting diode, LSI.

This is a self-linear structure for electronic circuits such as VLSI. Other uses include preventing radiation such as alpha rays on the surface of semiconductor devices. Furthermore, it is useful as an alignment film for liquid crystals and as an internal material for solar cells in applications other than semiconductor devices.

The present invention will be explained below with reference to Examples.

Example 1 Purified anhydrous paraphenylenediamine 0 in a 4-tube flask equipped with a thermometer, stirrer, and dry nitrogen gas inlet
．． 9 mol and 4147-diamitudiphenyl ether 0
．． Charge 1 mol of water and add anhydrous N to this.

A mixed solvent of 95% of N'-dimethylacetamide and 5% of anhydrous diacetone alcohol was added in an amount sufficient to make the solid content ratio in the total raw materials 15%. Next, 09 mol of purified anhydrous pyromellitic dianhydride and 0.1 mol of anhydrous benzophenonetetracarboxylic dianhydride were added.
mol was added in small portions with stirring, while 15° C. cold water was circulated to externally cool the rapidly exothermic reaction. After the addition, the internal temperature of the flask was set at 20° C., and while dry nitrogen gas was introduced, stirring was continued for 10 hours to advance the reaction.

After the reaction was completed, a portion of the mixture was poured into a large amount of water to precipitate polyamic acid, and after filtration, it was dried under reduced pressure at 1 maid for 16 hours. 0.5 f of the product was dissolved in 100 g of N-methyl-2-pyrrolidone, and the temperature was 3.
The intrinsic viscosity was measured at 0°C and found to be 1.5. The residue of the reaction product was diluted with N-methyl-2-pyrrolidone to 1096
The solution was diluted to a desired concentration and dropped onto a wire-bonded IC element by a dropping method. This was heated in a dryer at 150°C, 250°C, and 350°C for 1 hour each to form a polyimide film with a thickness of 10 μm. This element was hermetically sealed with a ceramic lid. The temperature during sealing is 500°C. The performance of the film on the IC is shown in Table 1.

The thermal decomposition initiation temperature was as high as 563°C.

Also, the amount of cracked gas generated (heated at 480℃ for 1 hour) is 2 pp
m, which is close to zero.

Therefore, when we investigated the internal gas of the hermetically sealed product, we found that there was almost no gas amount and that a sufficient hermetic seal was maintained. High temperature, high humidity bias test (85℃) of this IC
, 85% RH, IOV application), no defects occurred even after 2000 hours.

Comparative Example 1 Commercially available polyimide resin P was used as a substitute for the heat-resistant resin of Example 1.
A non-metically sealed product was prepared in the same manner as in Example 1 using yre-ML (manufactured by DuPont). The performance of this film is shown in Table 1.

The thermal decomposition starting temperature was 450°C, so decomposition gas was generated at the temperature (500°C) when the seal was sealed, and a large amount of gas accumulated inside the sealed product. In the reliability test (85℃, 851cm, 10V applied) of this IC, 200
hrs, the aluminum electrodes of the IC corroded, making it impractical.

Comparative Example 2 In Example 1, the reaction was stopped after 1 hour, and after the reaction was completed, it was poured into a large amount of water to precipitate the reaction product, which was then filtered and dried under reduced pressure. The intrinsic viscosity of the obtained polyamic acid was 0.3.

When a hermetically sealed product was produced in the same manner as in Example 1, cracks occurred in the film and it was very brittle.

Comparative Example 3 While maintaining the reaction temperature at 10° C. in Example 1, the reaction was continued with stirring for 25 hours. The intrinsic viscosity of the obtained polyamic acid was 3.5. In the same manner as in Example 1,
- Created a sealed product. As shown in Table 1, the thermal decomposition starting temperature of this film is 460°C, so decomposition gas is generated during sealing, and IC reliability tests (85°C, 85°C)
1. When IOV was added, a short circuit occurred in the aluminum electrode on the IC in 300 hrs.

Example 2 In the same apparatus as in Example 1, 0.7 mol of paraphenylenecyone as a diamine and 0.3 mol of 4,4'-diaminodiphenyl ether were dissolved in t-N-methyl-2-pyrrolidone, and pyromellitic acid was dissolved in this. A solution in which 0.9 mol of dianhydride and 0.1 mol of benzophenonetetracarboxylic dianhydride were dissolved in N-methyl-2-pyrrolid was added dropwise over 1 hour while stirring and flowing dry nitrogen. . N, N'- so that the solid content concentration in the solution is 10%.
Dimethylacetamide was added, and the reaction was allowed to proceed for 16 hours while maintaining the solution temperature at 20°C. The intrinsic viscosity of the obtained polyamic acid was 2.0. This product was diluted with toluene to a concentration of 5%, and applied using a spinner to a thickness of 2 μm on the surface of a silicon transistor equipped with an aluminum electrode. After heat treatment at 100° C. for 1 hour and 30 minutes at 250° C. in a tester, the film on the aluminum electrode is etched using a hydrazine etching solution to open the film. After etching, a heat treatment was performed at 400° C. for 30 minutes, and aluminum was then vapor-deposited thereon to produce a transistor with a two-layer structure. Furthermore, the electrode was annealed (500℃, 30℃
), and examined the change in the transistor current, and found that it was +0.
1% and #1 hardly changed. When pyreML (manufactured by DuPont) of Comparative Example 1 was used in a similar manner, the change in current after annealing was reduced by 155 times.

Comparative Example 4 Pyromellitic dianhydride was used as the acid anhydride in Example 2.
The reaction was carried out in the same manner except that 0 mol was used, and the intrinsic viscosity was 1
．． Polyamic acid No. 5 was obtained. This was applied on a silicon transistor in the same manner as in Example 2, but cracks occurred in the film when heat treated at 400°C for 30 minutes after etching.Comparative Example 5 Pyromellitic acid was used as the acid anhydride in Example 2. Dianhydride 0.
A polyamic acid having an intrinsic viscosity of 1.5 was obtained by reacting in the same manner except that 7 mol and benzophenonetetracarboxylic dianhydride were used. This was done in the same manner as in Example 2,
We created a transistor with a two-layer structure. The properties of the film are shown in Table 1.

Since the temperature at which thermal decomposition starts is 452°C, the transition temperature was 0.8 mol.
Dissolve 0.7 mol of para-phenylenediamine in dimethylformamide and stir with dry nitrogen flow.
mol and 4147-diamitudiphenyl ether 0.3
mol was added. N,N'-dimethylacetamide was added so that the solid content concentration in the solution was 15%, and then 2
The reaction was continued at 0°C for 200 hours. The intrinsic viscosity of the obtained polyamic acid was 1.0.

This product was spin-coated with a spinner onto a silicon urchin ≦1 on which a semiconductor element circuit of an ultra-LSI (64 bits) was formed, and heated at 100°C and 200°C for 1 hour each in a drying oven to coat the entire surface of the wafer with polyimide. A film with a thickness of 60 μm was formed. Next, apply a negative resist, dry it, then expose and develop it.
The film on the bonding butt was removed by etching using a hydrazine etching solution. 400 after negative resist removal
After heat treatment at 1:10° C., the silicon wafers were scribed and cut into 5 m+square chips. This semiconductor element was mounted on a ceramic substrate, bonded with gold wire, and then glass-sealed with ceramic 7-ta. The sealing temperature is 500°C.

Characteristics of the film on the device are shown in Table 1. The thermal decomposition onset temperature is extremely high at 540℃, and the amount of decomposition gas generated (480℃
, heating for 1 hour) was as low as 5 ppm.

Therefore, the hermetic seal had good airtightness, and no defects occurred for more than 2000 hours in a high temperature, high humidity reliability test (85° C., 85% RH, 110 V applied).

Furthermore, there were no malfunctions caused by alpha rays. When pyreML (manufactured by DuPont) used in Comparative Example 1 is used in a similar manner, the sealing element has a high temperature and high humidity bias test of 300 Mg.
A circuit disconnection failure occurred.

Comparative Example 6 Same as Example 3 except that 1 mol of para-phenylene diamine was used as the diamine. Intrinsic viscosity: 1.5
of polyamic acid was obtained. This was coated on a silicon wafer in the same manner as in Example 3, but the film cracked and peeled off after etching.

Comparative Example 7 Paraphenylenediamine 0,
5 moles and 0.4'-diaminodiphenyl ether.
Using 5 mol, a polyamic acid with an intrinsic viscosity of 1.5 was obtained. Using this product, a ceramic sealed VLSI product was produced in the same manner as in Example 3. The properties of this film are shown in Table 1. The temperature at which thermal decomposition started was 462°C, and the sealing element experienced a short circuit due to corrosion of the aluminum circuit in 400 hrs during a high temperature and high humidity bias test.

Example 4 Example 1 except that 0.9 mol of 2.3.6.7-naphthalenetetracarboxylic dianhydride and 0.1 mol of penzofumononetetracarboxylic dianhydride were used as acid anhydrides. A similar reaction was carried out to obtain a polyamic acid having an intrinsic viscosity of 1.5. When this was used as a surface protective film of an IC and ceramic sealed in the same manner as in Example 1, no defects occurred for more than 2000 hours in reliability tests, high temperature, high humidity, and bias tests.

Example 5 In Example 2, the diamine was m-phenyl diamine 0.
9 mol and H 4,4'-diaminodiphenyl ether 02
A polyamic acid having an intrinsic viscosity of 1.3 was obtained by reacting in the same manner except that molar amounts were used. A two-layer structure of a transistor was prepared in the same manner as in Example 2 and annealed at 500° C. for 30 minutes, but the current change was as small as -0.2 inches.

Example 6 In Example 3, 70.8 mol of diamino naphthalene and 0,2 mol of 4,4'-cya, minodiphenyl ether were used as diamines.
A polyamic acid having an intrinsic viscosity of 1.7 was obtained by reacting in the same manner except that molar amounts were used. Similar to Example 3, it was used as a protective film for a VLSI and sealed with ceramic, but
In the bias test, no defects occurred for more than 20.00 hrs, and there were no soft errors due to alpha rays.

Table 1 summarizes the performance of the films of Examples and Comparative Examples. As is clear from this, the heat-resistant polyimide resin used in the present invention has a high thermal decomposition initiation temperature of 480°C or higher,
Film-forming properties are also good.

Furthermore, when treated at a high temperature of 480° C. for 1 hour, the amount of decomposed gas generated is as low as 10 ppm or less, and the deterioration of withstand voltage is also small, which is an unprecedented feature.

The intrinsic viscosity of the resin used in the present invention must be within the range of 0.5 to 2.5; if it is less than 0.5, the cured product will be brittle and cracks will occur during film formation (Comparative Example 2). Moreover, when the intrinsic viscosity is 2.5 or more, the thermal decomposition initiation temperature of the cured product decreases (Comparative Example 3).

Among the acid anhydride components of the resin used in the present invention, benzophenonetetracarboxylic acid dianhydride requires a concentration of 1 to 20 mol. If the amount is less than 1 mol. ). Furthermore, if 20 molti or more is used, the thermal decomposition initiation temperature decreases and a product of 480° C. or higher cannot be obtained (Comparative Example 5).

Among the diamine components of the resin used in the present invention, 4,4'-diaminodiphenyl ether should be in the range of 1 to 40 mol. When the amount is less than 1 molty, the cured film becomes brittle (Comparative Example 6), and when more than 40 molty is used, the thermal decomposition initiation temperature becomes 480° C. or less (Comparative Example 7).

As mentioned above, the heat-resistant resin film used in the present invention is characterized by an improved thermal decomposition initiation temperature of 480°C or higher while maintaining the excellent properties of conventional polyimide resins. When this film is used as a protective film on the surface of a semiconductor element, the reliability of the element is far greater than before, as there is almost no deterioration of film properties or generation of decomposition gas due to high-temperature treatment during ceramic sealing or annealing of aluminum electrodes. can be improved.

applicant Sumitomo Bakelite Co., Ltd.

Claims (1)

Scope of Claims: 99 to 80 mol of tetracarboxylic dianhydride represented by (R, is a benzene ring, fused benzene ring) and (Xl is -CO-1-, -5O2-1-S-1 -CH
Tetracarboxylic dianhydride represented by 2-1 @1-2
A tetracarboxylic dianhydride consisting of 0 molti and a diamine represented by the general formula H,N-R2-Nl2 (R1 is a benzene ring, a condensed benzene ring) (D11 to 40 molti),
The intrinsic viscosity of the polyamic acid product reacted at 0 to 100°C under anhydrous conditions in an inert gas atmosphere in an organic polar solvent is 0.5 to 2.5, and the cured product after imidization is 1. A method for manufacturing a semiconductor device, comprising applying a heat-resistant resin having a thermal decomposition initiation temperature of 480 to 580° C. onto the surface of a semiconductor element, curing the resin by heating, and adhering the resin to the surface of the semiconductor element. (2) The heat-resistant resin according to claim 1, in which the material is pyromellitic dianhydride and (6) is penzophenone tetodicarboxylic dianhydride, is applied to the surface of a semiconductor element, and heated. A method for manufacturing a semiconductor device, characterized by curing and adhering to the surface of a semiconductor element. (3) The heat-resistant resin according to claims 1 and 2 (where Q is paraphenylene diamine and acyl (6) is 4,4'-diaminodiphenyl ether) is applied to the surface of a semiconductor element and cured by heating. 1. A method for manufacturing a semiconductor device, comprising: adhering it to a surface of a semiconductor element.