JPH02173043A - Organosilicon polymer - Google Patents

Abstract

PURPOSE:To obtain an organosilicon polymer excellent in heat resistance and useful for an interlaminar insulation film of a semiconductor device of a multilayer interconnection structure having a specified structural formula and a specified molecular weight. CONSTITUTION:This organosilicon polymer is represented by the general formula: [R1SiO2/2(R2)1/2]n (wherein R1 is a vinyl, an allyl, a lower alkyl, a lower alkoxy, an aryl or a lower haloalkyl; R2 is an arylene; and n is an integer of 10-50000, provided that at least 25% of R1 groups are lower haloalkyls) and has a weight-average MW of 3000-5000000. This polymer can be obtained by hydrolyzing an organosilicon compound of formula I (wherein R1 groups are the same or different from each other and each represents vinyl, aryl, hydrogen atom, hydroxyl, lower alkyl, aryl or lower haloalkyl, and at least 25% of them are lower haloalkyls; R2 is an arylene; and R3 groups are the same or different from each other and are each halogen atom or lower alkoxy) and polycondensing the hydrolyzate through dehydration.

Description

[Detailed Description of the Invention] [Summary] Regarding organosilicon polymers, the following general formula (1): % formula % (1 ) (In the above formula, R represents a vinyl group, allyl group, lower alkyl group, lower alkoxy group, aryl group or lower halogenated alkyl group, R2 represents an arylene group,
and n represents an integer of 10 to 50,000), R is at least 25% or more of a lower halogenated alkyl group, and 3,000 to 5,000,000
An organosilicon polymer having a weight average molecular weight of 0 or a hydrogen atom of a silanol group contained in the polymer is a triorganosilyl group represented by the following formula: (R) zSi- (in the above formula, (R), may be the same or different and are constituted by an organosilicon polymer substituted with a vinyl group, an allyl group, a lower alkyl group, an aryl group, or a lower halogenated alkyl group.

[Industrial Application Field] The present invention relates to a novel organosilicon polymer, a method for producing the organosilicon polymer, a semiconductor device using the organosilicon polymer as an interlayer insulating film, and a method for producing the semiconductor device. . More specifically, the present invention relates to an organosilicon polymer that forms a film having excellent heat resistance and photoresistance in the multilayer wiring formation process in the production of semiconductors such as various integrated circuits, a method for producing the same, and the silicon polymer. The present invention relates to a semiconductor device using a combination as an interlayer insulating film and a method for manufacturing the semiconductor device.

C. Prior Art] As is well known, high molecular weight polyorganosilsesquioxane is an organosilicon polymer useful in the manufacture of semiconductor devices, etc., and conventionally, organotrichlorosilane or organotrialkoxysilane is used as a starting material. As such, a method for obtaining such a high molecular weight polyorganosilsesquioxane by hydrolyzing the compound and subsequent dehydration condensation was known. It is said that such organosilicon polymers having trifunctional silicone as a structural unit have a partially or entirely ladder-shaped structure and maintain solubility in organic solvents. The same method has conventionally been used to prepare a linear organosilicon polymer having alternating soroxane bonds and zylarylene bonds, such as tetramethylsilphenylene siloxane, by dissolving 1,4-bis(hydroxydimethylsilyl)benzene in benzene, A method was also known in which the product was produced by subsequent condensation under reflux conditions while removing the water produced.

Further, one of the uses of the organosilicon polymer as described above is as an interlayer insulating film of a semiconductor device having a multilayer wiring structure.

The interlayer insulating film is formed by forming the first layer wiring, forming an insulating film, forming through holes on the insulating film to establish continuity between the upper and lower wiring layers, and then connecting the second layer wiring through the insulating film. This was essential because multilayer wiring was formed by repeating this process in sequence.

The materials used for the interlayer insulating film are conventionally inorganic materials such as silicon dioxide and phosphorous glass (PSG) formed by vapor phase growth using silane gas, oxygen gas, etc., or polymeric insulating materials such as polyimide and silicone resin. However, with the miniaturization of wiring patterns, there has been a demand for materials with better characteristics in terms of reliability.

When considering multilayer wiring, the semiconductor substrate with the first layer wiring has unevenness due to the wiring, so if you use this as a base and form an inorganic film on top of it, the surface of the interlayer insulating film will reproduce the unevenness of the base as it is. Put it away. This may cause disconnection or insulation failure in the upper layer wiring formed thereon. Therefore, it has been desired to develop an insulating material that can flatten an uneven base substrate.

Therefore, as an inorganic film formation method, a resin film is formed on the uneven surface of the inorganic film using a spin code method to flatten the surface, and then the film is uniformly scraped until the resin film is removed to obtain a flat inorganic film. Obtaining a flat insulating film surface by improving inorganic film forming processes such as the back method and bias sputtering method, which forms a flat inorganic film by simultaneously depositing and spacking the inorganic film while scraping the convex parts of the film. A method is being considered in which a film with a flat surface is obtained by forming a resin using a spin code method, which is heated and cured, and then used as is as an insulating film. Among these, the resin coating method, which is simple in terms of process, requires heat curing after spin coating, but at this time, through holes are formed to ensure continuity between the upper and lower wiring layers, and then heat curing is performed. This simplifies the process. However, in the semiconductor manufacturing process, a heat treatment step of 400°C or higher is performed, so polymer materials such as polyimide and silicone resin that have been used in the past may undergo oxidation or thermal decomposition of the film during heat treatment, or may undergo a hardening reaction. It has the disadvantage that it cannot withstand the internal strain of the film caused by oxidation, decomposition, etc. of the film, and the stress during heat treatment caused by the difference in coefficient of thermal expansion with other materials, resulting in cranking. Therefore, a patternable heat-resistant resin material that does not undergo any change during the heat treatment process has been desired.

[Problems to be solved by the present invention]

The first object of the present invention is to provide a novel organosilicon polymer useful in the field of semiconductor devices and the like, in view of eliminating the drawbacks of the conventional techniques as described above.

A second object of the present invention is to provide a method for producing such a novel organosilicon polymer.

A third object of the present invention is to provide a semiconductor device using such a novel organosilicon polymer.

A fourth object of the present invention is to manufacture a semiconductor device by imparting characteristics as a pattern forming material to such a novel organosilicon polymer and by simply performing a process of forming through holes for conducting conduction between upper and lower wiring layers. The purpose is to provide a method.

[Means to solve the problem]

The first and second problems mentioned above are solved using the following general formula % formula % (
1) (In the above formula, R2 represents a vinyl group, an allyl group, a lower alkyl group, a lower alkoxy group, an aryl group or a lower halogenated alkyl group, and Rt is, for example, an o-, m- or p-phenylene group, represents an arylene group such as tolylene group or naphthylene group, and n represents an integer from 10 to 50,000), and Rt is small (both 25 to 50,000).
% or more of lower halogenated alkyl groups, and 3,
This problem can be solved by organosilicon polymers having a weight average molecular weight of 000 to 5,000,000. The organosilicon polymer according to the present invention preferably has the following structural formula (1) or (
II) or a mixture thereof.

(In the above formula, R may be the same or different, and is the same as the above definition).

Furthermore, it is represented by the general formula (1), and to, o
In producing an organosilicon polymer having a weight average molecular weight of oo to 5,000.000, an organosilicon compound of the following formula (2): R2R.

(In the above formula, R, may be the same or different and are the same as defined above, R2 is the same as defined above, and R3 may be the same or different, for example, a halogen such as chlorine or a lower (representing an alkoxy group) is reacted with water to be hydrolyzed, and the resulting reaction product is subsequently subjected to dehydration polycondensation to obtain the general formula (1).
This problem can be solved by using organosilicon polymers.

Further, according to the present invention, the above-mentioned third problem is expressed by the above formula (1), and 10,000 to s, ooo
This problem can be solved by a semiconductor device having a multilayer wiring structure, which is characterized by having an interlayer insulating film made of an organosilicon polymer having a weight average molecular weight of , ooo.

Furthermore, the fourth problem mentioned above is that when the organosilicon polymer of formula 1 is used as an interlayer insulating film, ionizing radiation such as X-rays must be used to form through holes for conducting between upper and lower wiring layers before heat curing. This problem can be solved by pattern formation.

The organosilicon polymer that can be used to form the interlayer insulating film is preferably represented by the above general formula (1), in which R,
is -CHzCl, -CHC12, -CtHaCj'
.

-Czlll(/!z, -cgngcz*, etc., R2 is an arylene group, and n is lθ~50,
It is a polyorganosylarylene siloxane representing an integer of 000. Further, the arylene group is not particularly limited as long as it is an organic group having a benzene skeleton, but practically, a p- or m-phenylene group is preferable. Also,
Although the ratio of the dylarylene bond to the siloxane bond in the molecular chain of the polyorganosylarylene siloxane may be any value, it is preferable to have 25-t% or more of the dylarylene bond from the viewpoint of heat resistance.

Furthermore, the first to fourth problems can be more preferably solved by providing the following new organosilicon polymers.

That is, it is represented by the general formula (1) above, and 10
An organosilicon polymer having a weight average molecular weight of ,000 to 5,000,000, wherein the hydrogen atom of the silanol group contained in the polymer is a triorganosilyl group represented by the following formula: (R): +Si (In the above formula, R may be the same or different and represents a vinyl group, an allyl group, a lower alkyl group, an aryl group or a lower halogenated alkyl group); The problem can be solved by a method for producing an organosilicon polymer, a semiconductor device having a multilayer wiring structure, and a method for producing the device, which is characterized by having an interlayer insulating film made of the organosilicon polymer.

This organosilicon polymer is ahead of the curve in that when it is used as an interlayer insulating film, the formed insulating film is less susceptible to stress caused by thermal expansion of the wiring material, making it difficult for cranks to move. It is a material that is easier to use than organosilicon polymers. This is because the oxidative decomposition temperature of unsubstituted polycondensation reaction residues is more than 50°C higher than that of polyorganosilsesquioxane, making it suitable for use in high-temperature oxygen atmospheres. This is because the reaction results in a hard film with a high crosslinking density.

In particular, spin-coatable resin film materials used between wiring layers in the multilayer wiring process of semiconductor devices are heated at 400°C.
exposed to high temperature oxygen atmosphere.

Therefore, conventional polyorganosilsesquioxane membranes suffer from cranking due to oxidative deterioration, resulting in a decrease in reliability. On the other hand, the above-mentioned organosilicon polymers with unsubstituted reactive residues have a thermal oxidation and decomposition temperature of 400°C or higher, and form a hard cured film, so they are used as wiring materials with low thermal expansion (e.g., Poly- It can be used in combination with 5i) or in combination with a high thermal expansion wiring material (for example /M) in a thin film. In addition, the organosilicon polymer in which reactive residues have been substituted has a thermal oxidation and decomposition temperature of 400"C or higher, and the heat-cured film also has flexibility.
It can be used in thick films compared to organosilicon polymers with unsubstituted reactive residues. In this way, a semiconductor device using the above-described organosilicon polymer as an interlayer insulating film for multilayer wiring can have improved reliability compared to the conventional technology.

The organosilicon polymer substituted with a reactive residue of the present invention is a triorganosilane represented by the following formula: (R)zSiX (in the above formula, R is a vinyl group). , represents an allyl group, a lower alkyl group, an aryl group, or a lower halogenated alkyl group, and X represents a halogen, a cyano group, an isocyanato group, an isothiocyanato group) or a hexaorganodisilazane represented by the following formula: (R) xs iNS i (R)
s (In the above formula, R may be the same or different and is the same as the above definition) Hexaorganodisiloxane represented by the following formula: (R) 5siOsi (R) y (In the above formula, R is the same or a mixture thereof, to convert the hydrogen atoms of the silanol groups remaining in the polymer that did not contribute to the dehydration condensation polymerization to It can be synthesized by substitution with an organosilyl group; (R)xSi (in the above formula, R may be the same or different and is the same as defined above).

Furthermore, the fourth problem described above is expressed by the above formula (1), and the amount of 10,000 to 5,000,000 (7
) When using an organosilicon polymer having a weight average molecular weight as an interlayer insulating film, before heat curing, through-holes for conducting between upper and lower wiring layers are formed using X-rays, electron beams, etc. in the resin. This can be solved by irradiation with ionizing radiation.

In this case, R1 shown in the above general formula (1) contains at least 25% or more of a lower halogenated alkyl group. This lower halogenated alkyl group causes a crosslinking reaction with high sensitivity when the resin is irradiated with ionizing radiation, making it possible to form a negative pattern. This effect of the present invention is that it is possible to omit the step required to form through holes in the manufacturing process of semiconductor devices, and furthermore, due to the high sensitivity, throughput can be shortened, thereby reducing costs. .

[For production]

The polydiorganosyl arylene disiloxane resin according to the present invention is soluble in many organic solvents, and can be formed into a film by a conventional spin-coating method.

Therefore, a semiconductor substrate surface having an uneven surface can be easily planarized.

Further, this polydiorganosyl arylene disiloxane resin allows formation of a negative pattern with high sensitivity by irradiation with ionizing radiation. Therefore, it is possible to form through holes for establishing conduction between the upper and lower wiring layers without using a resist and in a short time.

Furthermore, even when heated in an oxygen atmosphere, this polydiorganosyl arylene disiloxane resin can maintain its film quality without being thermally oxidized up to 400° C. or higher. Therefore, it can be used as an interlayer insulating film without causing damage due to thermal oxidation in the manufacturing process of semiconductor devices.

〔Example〕

Subsequently, the present invention will be specifically explained with reference to some examples.

, Example - (Synthesis Example) A 300 cc four-bottle flask was charged with 1 oocc of methyl isobutyl ketone, 50 cc of methyl cellosolve acetate, and 30 cc of water, and 1 oocc of triethylamine was added as a catalyst.
5 cc was added, and the mixture was cooled to -60°C while stirring. 1. 10 g of 4-bis(chloromethyldichlorosilyl)benzene was dissolved in 50 cc of tetrahydrofuran and added dropwise to the fourth flask over 40 minutes. After the completion of the dropwise addition, the temperature of the system was raised at 2.0°C/sin. The mixture was heated to 80° C. and stirring was continued for 2 hours.

After the reaction was completed, the mixture was cooled to room temperature and washed with a large amount of water. The reaction solution washed with water was further subjected to azeotropy to remove residual water, and the solvent was replaced with ethyl cellosolve acetate. This solution was further reacted at 120°C for 2 hours. After the reaction was completed, the reaction solution was poured into a large amount of water to precipitate and collect the resin.

6.2 g of a white powder of polydichloromethyl-p-silphenylene disiloxane was obtained. The weight average molecular weight determined by gel permeation chromatography in terms of polystyrene was 1.5×10'.

Group I (Synthesis Example) Polydichloromethyl- obtained by the method described in Example 1 above
5 g of white powder of p-silphenylene disiloxane was dissolved in 100 cc of methyl isobutyl ketone, 20 cc of pyridine was added as a catalyst, and after heating to 60°C, 20 cc of methyltrichlorosilane was added and reacted at this temperature for 3 hours. The hydrogen atoms of unreacted hydroxyl groups were replaced (silylated) with trimethylsilyl groups. After the reaction was completed, 5.1 g of silylated polydichloromethyl-p-silphenylene disiloxane was obtained in the same manner as in Example 1 above. The weight average molecular weight determined by gel permeation chromatography in terms of polystyrene was 3.5×10′.

The polydichloromethyl p-silphenylene disiloxane obtained in Example 1 was dissolved in white powder lamethyl isobutyl ketone to obtain 20-t% polydichloromethyl p-silphenylene disiloxane.
A p-silphenylene dicycloxane resin solution was obtained.

The resin solution prepared as described above was applied to a silicon substrate on which a semiconductor element was formed and a first layer polysilicon wiring was applied (the thickness of polysilicon was 17 rm, the minimum line width was 1 tone, and the minimum line spacing was 1.5 am). ) by a spin code method under the conditions of 300 rpm and 45 seconds.

After coating, the solvent was dried at 80°C for 20 minutes, exposed to X-rays, and developed with methyl isobutyl ketone.
Form a 3-hole through hole and further drill 30mm at 250"C.
Heat treatment was performed at 400°C for 60 minutes. The level difference on the substrate surface after the heat treatment was approximately 0.2 mm, and the level difference caused by the wiring had been flattened. Next, a second layer of polysilicon wiring was formed, and a PSG film with a thickness of 1 was deposited as a protective layer by normal pressure CVD, and a window was opened for taking out the electrodes to obtain a semiconductor device.9 This device was installed in the atmosphere. 450'
Heating test for 1 hour at C, -65°C → 150°C for 10
No defects were observed even after multiple thermal cycle tests.

The white powder of silylated polydichloromethyl-p-sylphenyl disiloxane obtained in Example 2 was dissolved in methyl isobutyl ketone to obtain a 20 imt% silylated polydichloromethyl-p-sylphenyl disiloxane resin solution. I got it.

The resin solution prepared as described above was applied onto a silicon substrate (aluminum thickness: Lm, minimum line width: 1 line, minimum line spacing: 1.5 ts) on which a semiconductor element was formed and a first layer of aluminum wiring was provided. The coating was applied using a spin code method under the conditions of 3.00 rpm and 45 seconds.

After coating, the solvent was dried at 80°C for 20 minutes, exposed to X-rays, and developed with methyl isobutyl ketone.
3/I11 through hole is formed and further heated to 250°C.
Heat treatment was performed at 400°C for 30 minutes and at 400°C for 60 minutes. The level difference on the substrate surface after the heat treatment was about 0.2 μm, and the level difference caused by the wiring had been flattened. Next, a second layer of aluminum wiring is formed, and a one-wall thick P layer is formed as a protective layer.
After depositing the SG film by atmospheric pressure CVD, a window for taking out the electrodes was opened to obtain a semiconductor device. This device underwent a heating test of 1 hour at 450°C in the atmosphere, -65'C → 150°C.
No defects were observed even after 10 thermal cycle tests at °C.

[Effects of the Invention] Since the present invention is constructed as described above, it is possible not only to obtain a new and useful organosilicon polymer, but also to efficiently produce the polymer by a simple method. It's quite possible. Further, according to the present invention, a highly reliable interlayer insulating film is obtained which has photosensitivity and planarization function, and also has excellent heat resistance so that the film does not break even when used at high temperatures. Effects can be obtained, and furthermore, it is possible to obtain a semiconductor device having such an interlayer insulating film.

Claims (1)

[Claims] 1. The following general formula (1): [R_1SiO_2_/_2(R_2)_1_/_2]
__n...(1) (In the above formula, R_1 represents a vinyl group, allyl group, lower alkyl group, lower alkoxy group, aryl group, or lower halogenated alkyl group, R_2 represents an arylene group, and n is represents an integer from 10 to 50,000), and R_1 is at least 25
% or more of a lower halogenated alkyl group, and 3,0
An organosilicon polymer having a weight average molecular weight of 00 to 5,000,000. 2. In producing the organosilicon polymer according to claim 1, the organosilicon compound of the following formula (2) ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ (2) (In the above formula, R_1 is the same or may be different, and represents a vinyl group, allyl group, hydrogen, hydroxyl group, lower alkyl group, aryl group, or lower halogenated alkyl group, but contains at least 25% or more of lower halogenated alkyl groups, and R_2 is arylene and R_3 may be the same or different and represent a halogen or a lower alkoxy group) are reacted with water and hydrolyzed, and the resulting reaction product is subsequently subjected to dehydration condensation polymerization. The method for producing an organosilicon polymer according to claim 1, which comprises: 3. A semiconductor device having a multilayer wiring structure, characterized in that the organosilicon polymer of formula 1 according to claim 1 is used as an interlayer insulating film. 4. When the organosilicon polymer of formula 1 according to claim 1 is used as an interlayer insulating film, pattern formation is performed using ionizing radiation such as X-rays to form through holes for conducting conduction between upper and lower wiring layers. A method for manufacturing a semiconductor device. 5. The organosilicon polymer according to claim 1, wherein the hydrogen atom of the silanol group contained in the polymer is a triorganosilyl group represented by the following formula: (R)_3Si- (in the above formula, An organosilicon polymer characterized in that (R)_3 may be the same or different and is substituted with a vinyl group, an allyl group, a lower alkyl group, an aryl group, or a lower halogenated alkyl group. 6. In producing the organosilicon polymer according to claim 5, the organosilicon compound of the following formula (2): ▲ Numerical formula, chemical formula, table, etc. ▼... (2) (In the above formula, R_1 is They may be the same or different and represent a vinyl group, allyl group, hydrogen, hydroxyl group, lower alkyl group, aryl group, or lower halogenated alkyl group, but include at least 25% or more of lower halogenated alkyl groups, and R_2 is arylene group, and R_3 may be the same or different and represents a halogen or a lower alkoxy group) is reacted with water to be hydrolyzed, and the resulting reaction product is subsequently dehydrated. Condensation polymerization is performed, and the resulting organosilicon polymer is converted into a triorganosilane represented by the following formula: (R)_3Si
X (in the above formula, R represents a vinyl group, allyl group, lower alkyl group, aryl group, or lower halogenated alkyl group, and X represents a halogen, cyano group, isocyanato group, isothiocyanato group), or in the following formula Hexaorganodisilazane represented by the following formula: ▲ Numerical formula, chemical formula, table, etc. ▼ (In the above formula, R may be the same or different and is the same as the above definition) Hexaorganodisiloxane represented by the following formula: R)_3SiOSi(R)_3 (In the above formula, R may be the same or different and is the same as the above definition) or a mixture thereof to contribute to the dehydration condensation polymerization remaining in the polymer. The hydrogen atom of the silanol group that was not used is replaced by a triorganosilyl group represented by the following formula: (R)_3Si- (in the above formula, R may be the same or different and is the same as the above definition). A method for producing an organosilicon polymer, characterized in that: 7. A semiconductor device having a multilayer wiring structure, characterized in that the organosilicon polymer according to claim 5 is used as an interlayer insulating film. 8. A semiconductor device characterized in that when the organosilicon polymer according to claim 5 is used as an interlayer insulating film, pattern formation is performed using ionizing radiation such as X-rays to form through holes for conducting conduction between upper and lower wiring layers. Production method.