JPS6319826A - Semiconductor device - Google Patents

Abstract

PURPOSE:To realize excellent alpha-ray resistant properties and facilitate highly reliable operation under a high temperature and a high humidity by covering a semiconductor device and a lead wire partially with polyimide containing a specific repeating unit. CONSTITUTION:A semiconductor device and a lead wire are covered at least partially with polyimide containing a repeating unit expressed by the attached formula. In order to improve wetting with the surface of the semiconductor device, known coupling agent may be added to the covering resin and epoxysilane, aminosilane or the like may be employed. It is desirable to add 0.01-10 weight parts of the agent to 100 weight parts of the covering resin. Also, two or more types of compounds such as N-phenylmaleimide, N-norvolnen- imide and N, N'-ethylenebismaleimide which contain at least one unsaturated imide radical may be mixed with the covering resin. With this constitution, a semiconductor device with excellent alpha-ray resistant properties and especially with high moisture-resistant reliability under a high temperature and a high humidity can be obtained.

Description

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

[Conventional technology]

Conventionally, resin-sealed semiconductor devices have been exposed to higher temperature conditions (65 to 85°C,
95% relative humidity, 121°C, 2 atm supersaturated water vapor)
It was inferior in terms of operational reliability.

In resin-sealed semiconductor devices, gaps occur between the resin and the lead wires or at the interface between the resin and the semiconductor element, and moisture infiltrates from the outside through these gaps, causing damage to the At wiring and bonding pads on the element. This is because wires are likely to corrode and break.

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 achieve sufficient moisture resistance characteristics of the resin-sealed semiconductor device.

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, the packaging material V-+ (e.g.
Due to the α-ray energy generated from the trace amounts of uranium and thorium contained in the filler of TTL fat composition A for fiefdoms,
There are problems with the charge capacity in the cell and defects in one-node operation (soft errors).

[Problem that the invention seeks to solve]

As a countermeasure against this problem, a highly purified α-ray shielding material (for example, polyimide, etc.) is provided between the semiconductor element, the lead wire, and the sealing material.

However, α-ray shielding materials have poor adhesion and adhesion with semiconductor elements, and are not necessarily fully effective in preventing corrosion of the bare tAt wiring mentioned above.

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

[Means for solving problems]

△ Both partially represent the following general formula [A]: (wherein R and R' are the same or different C, H, CH,, C
2H5, CF3, C2F11 and C3F, and X is a divalent organic group).

Examples of X in formula I include the following general formula [B]: (in the formula Y
is a bond, -CH2-1-C(CH3)2-1-C(C
F3) 2-1-〇-1-CO-1-COO-1-8- and -502-, Ar represents a divalent organic group) There are groups that have

Examples of primary polyimides expressed by the above formula 1 are:
There is a polyimide represented by the following general formula [C] that contains acetylene groups at both ends.

The polyimide represented by the formula [A) or (03) can be obtained, for example, according to the following reaction formulas (1) to (3).

Among the compounds represented by abrasion, it is particularly advantageous to exhibit the effects of the present invention when X is represented by and R and R' are - or CH3.

Furthermore, in the present invention, the tetracarboxylic dianhydride represented by the following general formula: (wherein R and R' are synonymous with the formula CA) can be used, for example, as described in US Pat. No. 4,045,408. It can be obtained by different manufacturing methods.

Further, a known coupling agent may be added to the seedling resin of the present invention for the purpose of improving wetting to the surface of a semi-woven element. Examples of such coupling agents include known silane coupling agents such as epoxysilane, aminosilane, acryloylsilane, mercaptosilane, fluorosilane, and vinylsilane, metal alkoxides such as aluminum, titanium, and zirconium, or known chelate-based coupling agents. There are coupling agents, etc. The amount of addition is α01~10! with respect to 100 parts by weight of the coating resin. It is desirable to use within the range of .

The cost resin of the present invention may include a compound having one or more unsaturated imide groups, such as N-phenylmaleimide, N-norbornene imide, or the following general formula: [wherein R' is alkylene] a cycloalkylene group, an arylene group, or a divalent organic group substituted thereof], such as N, N'-ethylene bismaleimide, N, N'-hexamethylene hismaleimide, N, IJ ′-dodecamethylene bismaleimide,
N, N'-m-phinyl bismaleimito, N, N-4
,4-diphenyl ether bismaleimide, N,N-
4,4'-diphenylmethane bismaleimide, N, N
'-4,4'-dicyclohexylmethane bismaleimide, 2,2-bis(4-(4-maleimidophenoxy)
phenyl]furopane, 2,2-bis[5-)thyl-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-
proyl-4-(4-maleimidophenoxy)phenyl]propane, 2,2-bis[3-improvir-4-(
4-maleimidophenoxy phenyl propane, 2,
2-bis[3-butyl-4-(4-maleimidophenoxy)phenyl]propane, 2,2-bis(3-5ec-
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-
maleimidophenoxy)phenylcomethane, bis[6-
Methyl-4-(4-maleimidophenoxy)phenylcomethane, bis[3-l colo-4-(4-maleimidophenoxy)phenylcomethane, bis[3-bromo 4-(
4-Maleimidophenoxyphenylmethane, 1.1
゜1,3.3.3-hexafluoro-2,2-bis[4
-(4-maleimidophenoxy)phenyl]furopane,
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--2
Reimidophenoxy)phenyl]propane, 1. i
, 1,3,3.3-hexafluoro-2,2-bis I:
3.5-dibromo-4(4-maleimidophenoxy)phenyl]propane, 1.1.1.3.3.3-hexafluoro-2,2-bis[3-methyl-4(4-maleimidophenoxy)phenyl ] Propanato, and two or more of these can also be used in combination. Furthermore, mixtures of mono-substituted maleimide, tri-substituted maleimide, tetra-substituted maleimide and the above-mentioned substituted bismaleimide can also be used as appropriate.

Further, in the present invention, a cyanate ester compound can also be added. What is a cyanate ester compound?
For example, 1,2-dicyanatobenzene, 1,3-dicyanatobenzene, 1,4-dicyanatobenzene, 1,2-
Dicyanato 4-methylbenzene, 1,3-dicyanato 2-methylbenzene, 1,3-dicyanato 5-methylbenzene, 1,3.5-tricyanatobenzene, 1,
5-dicyanatonaphthalene, 4.4-dicyanatodiphenyl, 2,2-bis(4-cyanatodiphenyl)propane, i,4'-dicyanatodiphenylmethane, 4.4'
-dicyanato 3.3'-dimethoxycarbonyldiphenylmethane, 4.4'-dicyanatodiphenyl ether, 2,2-bis-(4-cyanato-3,5-dimethylphenyl)ethane, 2,2-bis-(4-cyanato-3,5-dimethylphenyl)ethane, anatophenyl)propane, 2j2-bis-(4-cyanatophenyl)butane, 4.4'-dicyanatopenzophenone, 1,
1-bis-(4-cyanatophenyl)-cyclohexane, 4.4'-dicyanatodiphenyl carbonate, 1.
Examples include polycyanate esters of 1.2-) lis-(4-cyanatophenyl)ethylbenzene and novolac phenolic resins.

In addition, the resins to be used in the present invention include epoxy resins, phenol resins, melamine resins, urea resins, diallyl phthalate resins, unsaturated polyester resins, urethane resins, addition polyimide resins, polyparavinylphenol resins, fluororesins, Polyphenylene sulfide, polyamide, polyether, polypropylene polyimide, polybenzimidazole, polybenzithiazole, polyoxadiazole, polypyrazole, polyquinoxaline, polythiazole, polytetraazopyrene, poly-4-phenyl-1
, 2,4-triazole, polyquinazolinedione, polybenzoxazolidine, etc. can also be added and blended.

Furthermore, a phenoxy resin represented by the following formula can also be added to the coating resin of the present invention. Commercially available phenoxy resins include Ciba Products.
Araldite 488E-32, Araldite 488N-40 from the Company family, PKHH, PKHA, PKHC from Union Carbide Plastics Company.
, PAHJ.

PKHS series and PRDA series, Dow Chemical Company's DER686MK40, DER
684MK40, Ebiletstu 2287 from John Sudapney Company, Noevonol 53-L-52, Evonol 55- manufactured by Shell Chemical Company.
40, Ebonol 55-L-32, Ebonol 55
-B-40 etc.

OH For example, the strength of the hydrogen bond between 10H and -C-OH in the OH group is 6kCa11 mol for the former, and 2 to 5k for the latter.
ce is said to be 17 moles, and the bond strength of fi and OH groups can be considered to be 2 to 5 times stronger than that of C○○H groups. Generally, polymers having OH groups (eg, polyvinyl butyral, phenoxy resin, etc.) have a small bond energy because they do not have ionic bonds like groups, which tend to be extremely effective in improving adhesiveness.

) It is said that the heat resistance imparting effect of ICmiC-R1-C=CH ethynyl-based compounds is due to the formation of an aromatic conjugated bond system as shown in the following formula; which improves heat resistance. . but,
It is questionable whether all -CmiOH in ethynyl compounds become aromatic rings, and this is currently being debated around the world.

〔Example〕

Hereinafter, the present invention will be explained with reference to examples! Although the present invention will be explained in more detail, the present invention is not limited to these embodiments.

Examples 1 to 6 The following five types of polyimide precursors...(ll) OH blind m/n molar ratio: Q, 05/α95 ll-(I
V) OH, each separately N-methylpyrrolidone 25
I made all the 10% varnish liquids based on the 0go.

Next, 1λ (Pill-D-RAM memory LSI (1
The above FES solution was dropped onto the elements and lead wires (including wire bonding) of 8 bottles). Then 100
℃ for 1 hour, 200℃ for 1 hour, 250℃ for 1 hour, 3
Heated at 00°C for 30 minutes to form an imide ring of the imide precursor (amic acid varnish), and a 30-60%
A coating film with a thickness of μm was obtained.

Next, the polyimide-coated memory LSI element was transferred and molded using the following epoxy resin sealing composition at 180°C, 70 to 9/cm", 1.5
The resin-sealed semiconductor device tIL was obtained by sealing and molding under the following conditions.

100 resin-sealed LSIs were heated at 121°C for 2 hours.
In pressure supersaturated water vapor (pressure, kutucates):
PCT) for a predetermined period of time, the LSIs were taken out to check whether the electrical operation was normal or not, and for abnormal LSIs, the failure was checked to see if the cause of the failure was disconnection due to corrosion of the At wiring, and the moisture resistance reliability was evaluated. The bamboo shoots are shown in the first column.

Creation of epoxy resin composition for fief land - As a polyfunctional epoxy compound, tris(hydroxyphenyl)methane paste polyfunctional epoxy compound XD-90
53 (manufactured by Dow Chemical Co., epoxy equivalent, 225) 1
00 weight L resin, 55 M parts of novolak type phenol resin (manufactured by Hitachi Kagyaku Co., Ltd., softening point 83°C) as a curing agent, and triethylamine tetraphenyl porate (manufactured by Hokuko Kagaku Co., Ltd., TEA-K) as a curing accelerator. ) 3 N
Can part, epoxy silane KBM as coupling agent
303 (manufactured by Hoechst Japan Co., Ltd.) 2 parts by weight, 5 parts by weight of addition-type imide coated red phosphorus as a flame retardant, 1 part calcium stearate as a mold release agent, and 1 part of Hoechst Wax E (manufactured by Hoechst Japan Co., Ltd.) 5 parts by weight, 490N34 parts by weight of fused silica glass powder as a filler, and 2 parts by weight of carbon black (manufactured by Capot Co., Ltd.) as a coloring agent were added.

Next, after stirring for 7 minutes with two 8-inch diameter rolls at 70 to 85°C, a resin composition was obtained by coarsely pulverizing.Comparative Example 1 Instead of the polyimide precursor in the above example, A varnish was prepared by dissolving 217 parts by weight of the polyimide precursor prepared in the same manner in 250 parts of N-methylpyrrolidone.

The PCT test results of the obtained 7'cIM bit D-PJI memory LSI were 10% and 10% after 500 hours of standing time.
It was 65% at 00 hours.

Test Example 1 A comparison of the characteristics of the present invention and each known material was carried out. The results are shown in Table 2 below.

Table 2 Example 7 Polyimide Precursor IJ) t-1) A varnish bath liquid with a single layer was prepared by dissolving it in a mixture of equal amounts of toluene and N-methylpyrrolidone. 1 and 2 show the device structure in case it is used as a wiring insulating film (2 layers).

That is, FIGS. 1 and 2 are cross-sectional views of a multilayer LSI element. In each figure, the code 1 is the S1 element substrate, 1-1
8102 insulating layer, 2-1 and 2-11 are aluminum wiring, 3-■ and 3-If are polyimide coating layers according to the present invention, and 4 is an epoxy resin coating layer.

To create the device, a 5i02 insulating layer (
1-1), and the first layer of aluminum wiring (2-1)
After forming the phenol, the above-mentioned phenol was coated with a tint/ner and baked (250°C, 60 minutes) (5-1), and then a body resist was coated to pattern a manhole. Next, plasma etching was performed using CF4-02 as a reaction gas.

Then 0! The positive resist was removed by plasma asher using all reaction gases.

Next, after forming a second layer of aluminum wiring (2-II), the above phenol was further applied and baked (under the same conditions as above) (3-n).

In addition, Fig. 2 shows the fc
The case was shown.

〔Effect of the invention〕

As described above, the present invention has the remarkable effect of providing a semiconductor device that is excellent in resistance to alpha rays and has particularly high reliability in humidity resistance under high temperature and high humidity conditions.

[Brief explanation of the drawing]

1 and 2 are cross-sectional views of a multilayer LSI element which is an example of the semiconductor device of the present invention. 1: 81 element substrate, 1- ■: 5i02 absolute layer, 2-
1 and 2-■ Nialuminum arrangement! , 3-1 and 5-■:
Polyimide covering layer of the present invention, 4: Epoxy resin wave O layer

Claims (1)

[Claims] 1. At least a part of the semiconductor element and the lead wire have the following general formula [A]: ▲There are mathematical formulas, chemical formulas, tables, etc.▼...(A) (In the formula, R and R' are , same or different, H, CH_3,
C_2H_5, CF_3, C_2F_5 and C_3F_
7, and X represents a divalent organic group. 2. The divalent organic group represented by X has the following general formula [B]
: ▲There are mathematical formulas, chemical formulas, tables, etc.▼...[B] (In the formula, Y is a bond, -CH_2-, -C(CH_3)_
2-, -C(CF_3)_2-, -O-, -CO-, -
The semiconductor device according to claim 1, which is a group having a repeating unit represented by COO-, -S-, and -SO_2, and Ar represents a divalent organic group. . 3. Claim 1 or 3, wherein the polyimide is a polyimide having acetylene groups at both ends represented by the following general formula [C] ▲ Numerical formula, chemical formula, table, etc. ▼...[C] The semiconductor device according to item 2.