JPH10194753A - Formation of silica ceramic coating and ceramic coating formed by this method of formation - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a silica ceramic coating of a substrates of semiconductor devices, etc., which coating has excellent abrasion resistance, thermal resistance and corrosion resistance, and high denseness and homogeneity without reversely affecting the substrate, by coating the substrate with a (modified) polysilazane having a skeleton consisting of specific structural units, then making the coating contact with amines and water vapor at the predetermined temperature, and firing the substrate in dry atmosphere. SOLUTION: This silica ceramic coating is produced by coating a substrate (for example, a silicone wafer) with a (modified) polysilazane (for example, perhydropolysilazane) of the formula R<1> -R<3> are each H, a group in which an atom connected directly with Si is C, such as (cyclo)alkyl, alkenyl, aryl, fluoroalkyl, alkylsilyl, alkylamino or alkoxy, provided that one or more of R<1> -R<3> are H) and its number-average molecular weight of approximately 100-50,000, making the coating contact with amines (for example, monomethylamine) and water vapor at 0-10 deg.C, then firing the substrate in dry atmosphere preferably at 350-450 deg.C.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for forming a siliceous ceramic film and a ceramic film formed by the method. More specifically, the present invention is excellent in heat resistance, abrasion resistance, corrosion resistance, etc., and is dense and homogeneous. The present invention relates to a method for forming a siliceous ceramic film that does not adversely affect a semiconductor element when applied to a semiconductor insulating film, for example, and to a siliceous ceramic film formed by the same method.

[0002]

2. Description of the Related Art Silica coatings are used, for example, between a semiconductor substrate and a metal wiring layer in a semiconductor device, between metal wiring layers, or on a semiconductor substrate in view of excellent heat resistance, abrasion resistance, corrosion resistance and the like. As an insulating film provided on various elements, as an insulating film provided between a glass substrate and an ITO film in a liquid crystal display device, between a transparent electrode and an alignment film, or provided on a pixel electrode or a color filter. Used as a protective film. A siliceous film used in such a field is generally formed on a substrate by a vapor phase growth method such as a CVD method or a sputtering method or a coating method using a coating liquid for forming a siliceous film. However, according to the vapor phase growth method, it is troublesome and requires large facilities, and furthermore, when a coating is formed on the uneven surface, there is a problem that the uneven surface cannot be flattened.
In recent years, a coating method has been widely adopted.

On the other hand, in recent years, polysilazane, a precursor polymer of silica, silicon nitride, and silicon oxynitride, has been attracting attention because it can form a siliceous coating film having excellent heat resistance, abrasion resistance, corrosion resistance, and the like. In addition, a coating solution for forming a siliceous film containing a cyclosilazane polymer or polysilazane has been proposed (JP-A-62-88327, JP-A-1-203476). However, when using such a coating solution to obtain a siliceous film in which most of the Si—N bonds have been converted to Si—O bonds, it is necessary to heat to about 900 ° C. There is a problem that cracks and the like are easily generated in the coating.

To solve such a problem, the following general formula (II)

Embedded image (Wherein, R ¹¹ , R ¹² and R ¹³ are each independently a hydrogen atom or an alkyl group having 1 to 8 carbon atoms) formed from a coating solution containing a polysilazane having a repeating unit represented by the following formula: Semiconductor device having a silica-based insulating film obtained by heating and curing a coating film in an oxidizing atmosphere (WO93 / 0
2472) and a coating solution for forming a silica-based film formed by mixing a polysilazane having a repeating unit represented by the above general formula (II) with a silicon compound having a siloxane bond (Japanese Patent Application Laid-Open No. 6-73340). Gazette) has been proposed.

When a siliceous film is formed by using these coating solutions, denseness and crack resistance can be obtained by firing at 450 ° C. for perhydropolysilazane and at 800 ° C. for organopolysilazane. It is possible to obtain a siliceous coating excellent in properties and the like.
However, from the viewpoint of manufacturing a semiconductor device, a liquid crystal display device, and the like, the above-mentioned firing temperature is too high, and is still insufficient in terms of low-temperature formation of a siliceous film. Further, in the conventional method, low molecular weight components of polysilazane are scattered at the time of heating, causing loss of a coating film and contamination of a firing device, which is not practical.

[0006]

Therefore, in order to solve such a problem, the present inventors have first prepared a polysilazane or a modified product thereof before or after applying the polysilazane on a substrate. Or amines and / or
Alternatively, a method has been proposed in which a base material having a silica-based coating having a denser and more uniform surface at a lower temperature than in the past is proposed by bringing into contact with an acid and curing and baking in an atmosphere (system) containing water vapor. Japanese Patent Application No. 7-344767.
However, even with this method, when a silica thin film used for a semiconductor insulating film or the like is formed, more mild conditions are desired. This is because when a technique of baking a polysilazane thin film in air to obtain a high-purity silica thin film is used for a semiconductor insulating film or the like, the upper limit of the baking temperature is about 450 ° C., which is the heat resistance temperature of the Al wiring. It is necessary to introduce water vapor into the atmosphere in order to completely convert this into silica at 450 ° C., and high-temperature water vapor may adversely affect the semiconductor element. As a result, 4
A process that can convert silica at 50 ° C. or lower is desired.

Therefore, the present invention is not only excellent in abrasion resistance, heat resistance, corrosion resistance, etc., but also in a dry atmosphere at 450 ° C.
It can be converted to silica in the following, and has excellent denseness (etching rate). For example, even when used as an insulating film or an alignment film of a semiconductor device, a liquid crystal display device, etc., it does not adversely affect those devices. It is an object of the present invention to provide a method of forming a siliceous ceramic film that does not cause loss of the film or contamination of a firing device, and a siliceous ceramic film formed by the method.

[0008]

According to the present invention, first, mainly the following general formula (I):

Embedded image (In the formula, R ¹ , R ² and R ³ each independently represent a hydrogen atom, an alkyl group, an alkenyl group, a cycloalkyl group, an aryl group, or a group other than these groups which is directly bonded to silicon such as a fluoroalkyl group. Represents a group that is carbon, an alkylsilyl group, an alkylamino group, or an alkoxy group, provided that at least one of R ¹ , R ^2, and R ³ is a hydrogen atom. After applying polysilazane having a number average molecular weight of about 100 to 50,000 or a modified product thereof on a substrate, contacting with amines and water vapor at a temperature of 0 ° C. to 100 ° C., followed by firing in a dry atmosphere. A method for forming a characteristic siliceous ceramic film is provided. Secondly, there is provided a siliceous ceramic coating formed by the method described in the first aspect.

The following is a summary of embodiments of the present invention. (1) The method for forming a siliceous ceramic coating as described in (1) above, wherein the modified polysilazane is obtained by adding Pd or Pt. (2) The method for forming a siliceous ceramic coating as described in (1) above, wherein the modified polysilazane is obtained by adding HMDS. (3) The method for forming a siliceous ceramic coating as described above, wherein the modified polysilazane is obtained by adding an alcohol.

That is, in the method for forming a siliceous ceramic film of the present invention, the number average molecular weight of the skeleton having the structural unit represented by the general formula (I) is about 100 to 5
After applying 0000 polysilazane or a modified product thereof (hereinafter simply referred to as polysilazane having a unit of the general formula (I)) onto a base material, the polysilazane or a modified product thereof is converted into a ceramic to form a ceramic. In forming a siliceous ceramic film on the substrate, after applying the polysilazane or a modified product thereof on a base material, contacting with amines and water vapor at a temperature of 0 ° C to 100 ° C, and baking in a dry atmosphere. Since the polysilazane or a modified product thereof is completely converted in a dry atmosphere at 450 ° C. or less, it has almost no adverse effect on the semiconductor element, and has a dense and uniform surface. Thus, a siliceous ceramic coating can be obtained. Further, according to this method, the amines are completely scattered out of the film during the firing, and the possibility that water vapor introduced at a low temperature adversely affects the semiconductor element is extremely small.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail. The method for forming a siliceous ceramic film according to the present invention is characterized in that the number average molecular weight having a skeleton composed mainly of the structural unit represented by the general formula (I) is about 100 to 50,000.
After applying polysilazane or its modified product on a substrate, contacting the polysilazane or its modified product with amines and water vapor at a temperature of 0 ° C. to 100 ° C., followed by firing in a dry atmosphere. And

[0012] In recent years, semiconductor circuits such as VLSIs are mainly stacked in a stepwise manner in order to increase the degree of integration.
Therefore, if the internal stress is large, cracks are likely to occur during lamination. However, in the method of the present invention, first, the polysilazane film is oxidized by steam using amines as a catalyst at a low temperature near room temperature. At this point, 30 of the polysilazane
% Or more is converted to silica. After that, it is completely converted to silica by firing in a dry atmosphere. For this reason, film shrinkage is small and internal stress is small as compared with the conventional method of converting silica into silica in a high-temperature atmosphere containing water vapor.

Polysilazane has a wide molecular weight of hundreds to tens of thousands. For this reason, when the polysilazane coating is heated, the low molecular weight components reach the boiling point and are scattered as vapor. This vapor may adhere to the inside of the heating device and cause particles. However, in the method of the present invention, the low molecular weight component is converted into high molecular weight and converted into silica at room temperature with amines and water vapor, so that no polysilazane vapor is generated during the subsequent heating. Therefore, the film yield, that is, the film thickness (weight) of silica obtained from the polysilazane film is larger than that of the conventional method.

The polysilazane used in the present invention may be any polysilazane having at least a Si—H bond or an N—H bond in the molecule. Not only polysilazane alone, but also a copolymer of polysilazane and another polymer or polysilazane may be used. A mixture of polysilazane and another compound can also be used. The polysilazane to be used includes a polysilazane having a chain, cyclic or cross-linked structure, and a polysilazane having a plurality of these structures in a molecule at the same time, and these can be used alone or as a mixture.

The following are typical examples of the polysilazane to be used, but are not limited thereto. The compound having a hydrogen atom at R ¹ , R ² and R ³ in the general formula (I) is perhydropolysilazane, and its production method is described in, for example, JP-A-60-145903, D.C. Se
Communication of A, yferth et al.
m. Cer. Soc. , C-13, January 1
983. Has been reported to. What is obtained by these methods is a mixture of polymers having various structures,
Basically, it contains a chain part and a cyclic part in the molecule,

Embedded image Can be represented by the following chemical formula.

An example of the structure of perhydropolysilazane is as follows.

Embedded image

In the general formula (I), R ¹ and R ^{2 represent} a hydrogen atom, R
^The method for producing a polysilazane having a methyl group at ³ is described in D.
Seeyferth et al., Polym. Prepr. Am. C
hem. Soc. , Div. Polym. Chem,.
25, 10 (1984). The polysilazane obtained by this method has a repeating unit of-(Si
H ₂ NCH ₃₎ - is a chain polymer and a cyclic polymer,
None have a crosslinked structure.

In the general formula (I), R ¹ and R ^{2 represent} a hydrogen atom, R
^The method for producing a polyorgano (hydro) silazane having an organic group at ³ is described in D.S. Seeyferth et al., Polym. Pre
pr. Am. Chem. Soc. , Div. Poly
m. Chem,. 25, 10 (1984), JP-A-61-61
-89230. The polysilazanes obtained by these methods include-(R ² SiHNH)-
Having a cyclic structure having a degree of polymerization of 3 to 5 as a repeating unit or (R ³ SiHNH) _x [(R ² SiH)
_1.5 N] _1-X (0.4 <X <1) Some molecules have both a chain structure and a cyclic structure in a molecule represented by the chemical formula.

In the general formula (I), R ^{1 represents} a hydrogen atom, R ² and R ³
A polysilazane having an organic group at R ¹ and R ² , an organic group at R ¹ and R ² , and a hydrogen atom at R ³ are represented by-(R ¹ R ² SiN
R ³⁾ - as a repeating unit, mainly the degree of polymerization has a cyclic structure 3-5.

Next, among the polysilazanes used, typical examples other than those represented by the general formula (I) will be described. Some polyorgano (hydro) silazanes include D.I. Seeferth et al. Co
mmunication of Am. Cer. So
c. C-132, July 1984. Some have a crosslinked structure in the molecule as reported. An example is as follows.

Embedded image

A polysilazane R ¹ Si (NH) _x having a crosslinked structure obtained by ammonia decomposition of R ¹ SiX ₃ (X: halogen) as reported in JP-A-49-69717, or R ¹ SiX ₃ and R ² ₂ Si
Polysilazane having the following structure obtained by co-ammonium decomposition of X ₂ can also be used as a starting material.

Embedded image

The polysilazane used has a main skeleton composed of the unit represented by the general formula (I) as described above, but the unit represented by the general formula (I) can be cyclized as apparent from the above. In such a case, the cyclic portion serves as a terminal group, and when such cyclization is not performed, the terminal of the main skeleton can be a group similar to R ¹ , R ² , or R ³ or a hydrogen atom. .

As a modified polysilazane, a polymetallosilazane containing a metal atom, for example, having the following structure (wherein M, which is a side chain metal atom, may be crosslinked), is also used as a starting material. be able to.

Embedded image

In addition, a repeating unit as reported in JP-A-62-195024 is represented by [(SiH ₂ ) _n
(NH) _m ] and [(SiH ₂ ) _r O] (wherein
n, m, and r are 1, 2 and 3, respectively), and the heat resistance produced by reacting a boron compound with polysilazane as reported in JP-A-2-84437. Excellent polyborosilazanes, polymetallosilazanes produced by reacting polysilazanes with metal alkoxides as reported in JP-A-63-81212, JP-A-63-191832 and JP-A-2-77427. JP-A-1-138108, 1-
No. 138107, No. 1-203429, No. 1-203
No. 430, 4-63833 and 3-320167, the molecular weight was increased (the former four of the above publications) and the hydrolysis resistance was improved (the latter two). And inorganic silazane high polymers and modified polysilazanes described in JP-A-2-175726, JP-A-5-86200, and JP-A-5-86200.
Copolymerized silazanes obtained by introducing an organic component into polysilazane, which are advantageous for thickening as reported in JP-A-331293 and JP-A-3-31326, JP-A-5-238827, JP-A-6-122852, Kaihei 6-29918
JP-A-6-306329, JP-A-6-24020
No. 8, Japanese Patent Application Laid-Open No. 7-196986, and can be applied to metals such as plastics and aluminum in which a catalytic compound for accelerating ceramic formation is added or added to polysilazane. Low-temperature ceramicized polysilazane, which is ceramicized at a low temperature, can be used in the same manner.

In the present invention, the following low-temperature ceramicized polysilazane can be used. For example, polysilazane added with silicon alkoxide described in Japanese Patent Application Laid-Open No. Hei 5-23827 by the applicant of the present invention can be mentioned. This modified polysilazane is obtained by combining the polysilazane represented by the general formula (I) with the following general formula (II)
I): Si (OR ⁴ ) ₄ (III) (wherein R ⁴ may be the same or different and represents a hydrogen atom, an alkyl group having 1 to 20 carbon atoms or an aryl group, and at least 1 R ⁴ is the above-mentioned alkyl group or aryl group).
A silicon alkoxide-added polysilazane having a polysilazane-derived silicon atom ratio in the range of 0.001 to 3 and a number average molecular weight of about 200 to 500,000.

Another example of the low temperature ceramicized polysilazane is glycidol-added polysilazane described in JP-A-6-122852 by the present applicant. The modified polysilazane is obtained by reacting the polysilazane represented by the general formula (I) with glycidol, and has a glycidol / polysilazane weight ratio of 0.001.
And glycidol-added polysilazane having a number average molecular weight of about 200,000 to 500,000.

As still another example of the low temperature ceramicized polysilazane, Japanese Patent Application Laid-Open No. 6-306329 by the present applicant is disclosed.
Acetylacetonate complex-added polysilazane described in Japanese Patent Application Laid-Open No. H10-260, 1989. This modified polysilazane is obtained by reacting the polysilazane represented by the general formula (I) with an acetylacetonate complex containing nickel, platinum, palladium or aluminum as a metal, and has a weight ratio of acetylacetonato complex / polysilazane of 0. 0.0000000
An acetylacetonato complex-added polysilazane having a number average molecular weight of about 200 to 500,000 within a range of 1 to 2. The metal-containing acetylacetonate complex is a complex in which an anion acac ⁻ generated by acid dissociation from acetylacetone (2,4-pentadione) is coordinated to a metal atom,
Generally represented by the formula (CH ₃ COCHCOCH ₃ ) _n M, wherein M represents an n-valent metal.

As another example of low temperature ceramicized polysilazane, Japanese Patent Application Laid-Open No. 6-299118 by the present applicant has been disclosed.
And polysilazane added with a metal carboxylate described in Japanese Patent Application Laid-Open (JP-A) No. 6-222,878. The modified polysilazane is a polysilazane represented by the general formula (I) and at least one metal selected from the group consisting of nickel, titanium, platinum, rhodium, cobalt, iron, ruthenium, osmium, palladium, iridium, and aluminum. Is a metal carboxylate-added polysilazane having a metal carboxylate // polysilazane weight ratio in the range of 0.000001 to 2 and a number average molecular weight of about 200 to 500,000 obtained by reacting a metal carboxylate containing . The metal carboxylate has a formula (R
COO) _n M wherein R is an aliphatic or alicyclic group having 1 to 22 carbon atoms, M represents at least one metal selected from the above metal group, and n is a metal Which is the valence of M]. The metal carboxylate may be an anhydride or a hydrate. The metal carboxylate / polysilazane weight ratio is preferably from 0.001 to 1, more preferably from 0.01 to 0.5. For the preparation of the polysilazane to which the metal carboxylate is added, see the above-mentioned Japanese Patent Application No. 5-93275.

In addition, those obtained by reacting an organic or inorganic polysilazane with an alcohol, an ester, an aldehyde, an isocyanate, an amide or a mercaptan can be used.
(JP-A-5-345826, JP-A-6-240208)
No. each publication). Further, a polysilazane stabilized with a silylating agent such as HMDS can also be used (JP-A-4-630).

In the method for forming siliceous ceramics according to the present invention, the above-mentioned polysilazane (modified product) is applied to a substrate, then brought into contact with amines and water vapor at a low temperature, and then fired in a dry atmosphere. That is, first, a process of applying the polysilazane (modified product) to a substrate is performed.
In the treatment, the polysilazane (denatured product) is dissolved in an organic solvent to prepare a coating solution. The organic solvent in this case is not particularly limited, but preferred specific examples include the following.

Aromatic compounds such as benzene, toluene, xylene, ethylbenzene, diethylbenzene, trimethylbenzene and triethylbenzene; n-pentane, i-
Pentane, n-hexane, i-hexane, n-heptane, i-heptane, n-octane, i-octane, n-
Saturated hydrocarbon compounds such as nonane, i-nonane, n-decane and i-decane; ethylcyclohexane, methylcyclohexane, cyclohexane, cyclohexene, p-menthane, decahydronaphthalene, dipentene; ethers such as dipropyl ether and dibutyl ether ; MIBK
Ketones and the like.

The prepared coating solution is then applied on a substrate. The application to the base material may be performed once, or may be repeatedly performed two or more times. The substrate on which the coating liquid is applied is not particularly limited, and may be any of metals, ceramics, plastics, and the like. As a coating means, a usual coating method, that is, a spin coating method, a dipping method, a spray method, a transfer method, or the like is used. If the base material is sanded, degreased, and surface-treated with various types of plasts before application, the adhesion performance of polysilazane (modified) is improved.

The polysilazane (modified) applied on the substrate is then contacted with amines and water vapor at a low temperature. The amines used herein include, for example, amines represented by the following general formula (IV), pyridines and DB
U and DBN are also included, and the acids include organic acids and inorganic acids. Formula (IV) R ⁴ R ⁵ R ⁶ N (IV) (wherein R ^{4 to} R ⁶ are each a hydrogen atom, an alkyl group,
Represents an alkenyl group, a cycloalkyl group, an aryl group, an alkylsilyl group, an alkylamino group or an alkoxy group. The following are specific examples. Methylamine, dimethylamine, trimethylamine, ethylamine, diethylamine, triethylamine, propylamine, dipropylamine, tripropylamine, butylamine, dibutylamine, tributylamine, pentylamine, dipentylamine, tripentylamine, hexylamine, dihexylamine, triethylamine Hexylamine, heptylamine, diheptylamine, octylamine, dioctylamine, trioctylamine, phenylamine, diphenylamine, triphenylamine and the like. (The hydrocarbon chain may be straight or branched.)

Examples of the pyridines include pyridine, α-picoline, β-picoline, γ-picoline, piperidine, lutidine, pyrimidine, pyridazine and the like. Further, DBU (1,8-diazabicyclo [5,
4,0] 7-undecene) and DBN (1,5-diazabicyclo [4,3,0] 5-nonene).

The method for contacting the polysilazane (modified) with amines and water vapor includes polysilazane (modified).
Is exposed to a mixed gas atmosphere of vapors of amines and water vapor, and is immersed in an aqueous solution of amines. In the above method, the concentration of amine vapor and water vapor is determined as follows: amine vapor / water vapor ratio = 0.01 to 1
The pressure is preferably 0.0001 to 5 kg / cm ² G, and more preferably 0.0001 to 0.5 kg / cm ² G.
Air and an inert gas can be used as a diluting gas when diluting. The contact temperature between the polysilazane (modified) and the vapor of the amines and water vapor is 0 ° C. to 100 ° C., preferably 10 ° C. to 30 ° C., and the contact time between the polysilazane (modified) and the amines and water vapor is 0.1 ° C. 1 second to 3
0 minutes, preferably 5 seconds to 3 minutes. In the above method, the amine concentration in the aqueous solution of the amine is 0.01
-80% by weight, preferably 0.1-10% by weight;
The temperature of the aqueous solution of amines is 0 ° C to 100 ° C, preferably 10 ° C to 50 ° C, and the contact time between the polysilazane (modified product) and the aqueous solution of amines is 0.1 second to 30 minutes, preferably 5 seconds. ~ 3 minutes.

The polysilazane (modified product) is converted into silica by contact with the vapor of the above-mentioned amines and water vapor, and 30% or more of the polysilazane (modified product) is fired in a dry atmosphere. Is completely converted to silica. This firing step is performed in a dry atmosphere, that is, an atmosphere that does not contain water vapor such as dry air, dry nitrogen, and dry He, and has a firing temperature of 200 ° C. or higher, preferably 3 ° C.
It is carried out at a temperature of 50 to 450 ° C. or more and a sintering time of 5 minutes or more, preferably 30 minutes or more.

The contact treatment with amines and water vapor at a low temperature and the subsequent calcination treatment in a dry atmosphere according to the present invention provide Si-N, Si in the polysilazane (modified).
The -H, NH bonds and the like disappear, and a tough siliceous ceramic coating mainly composed of Si-O bonds can be formed.

The substrate provided with the silica-silica ceramic coating of the present invention may be, for example, a semiconductor device, a liquid crystal display device,
Photomask with phase shifter, LS with multilayer wiring structure
It is used as an electronic device such as an I element and a printed circuit board, a hybrid IC, an alumina substrate, and a three-layer resist.

More specifically, in a semiconductor device, for example, a siliceous ceramic film is formed between a semiconductor substrate and a metal wiring layer and between metal wiring layers, and a PN junction semiconductor provided on the semiconductor substrate, a capacitor element, a resistor, Various elements such as elements are coated with a siliceous ceramic coating,
The uneven surface formed by these elements is flattened. In a liquid crystal display cell of a liquid crystal display device, a siliceous ceramic is provided between the transparent electrode of the transparent electrode plate and the transparent electrode, and between the transparent electrode of the transparent electrode plate having an alignment film on the transparent electrode and the alignment film. In the liquid crystal display cell in the color liquid crystal display device, a siliceous film is formed on the pixel electrode of the electrode plate and on the color filter of the counter electrode plate, and the uneven surface formed by the pixel electrode and the color filter is formed. Flattened by siliceous coating. Further, the phase shifter of the photomask with a phase shifter and the intermediate layer of the three-layer resist are composed of a siliceous ceramic film, and the electronic component is also provided with the siliceous ceramic film similarly to the semiconductor device. The surface to be coated is flattened by the siliceous ceramic coating.

The siliceous ceramic coating of the present invention is obtained by applying the coating solution containing the polysilazane (modified product) onto the above-mentioned base material, and then contacting with the amines and water vapor at the low temperature, and It is formed by performing a subsequent baking process in a dry atmosphere. The siliceous coating is usually 0.01 to 5 μm, preferably 0.1 to 5 μm.
2 μm.

[0041]

The present invention will be described in more detail with reference to the following Examples, which should not be construed as limiting the technical scope of the present invention.

Reference Example 1 [Synthesis of perhydropolysilazane] A four-necked flask having an inner volume of 1 liter was equipped with a gas blowing tube, a mechanical stirrer, and a dewar condenser. After replacing the inside of the reactor with deoxygenated dry nitrogen, 490 ml of degassed dry pyridine was put into a four-necked flask, and the mixture was cooled with ice. Next, 51.9 g of dichlorosilane was added, and a white solid adduct (SiH ₂ Cl ₂ .2C ₅ H) was added.
₅ N) was produced. The reaction mixture was ice-cooled, and while stirring, 51.0 g of purified ammonia was blown through a sodium hydroxide tube and an activated carbon tube, and then heated to 100 ° C.

After completion of the reaction, the reaction mixture was centrifuged, washed with dry pyridine, and then filtered under a dry nitrogen atmosphere to obtain 850 ml of a filtrate. The solvent was removed from 5 ml of the filtrate under reduced pressure to obtain 0.102 g of a resinous solid perhydropolysilazane.

The number average molecular weight of the obtained polymer was 1,120 as measured by a freezing point depression method (solvent: dry benzene). IR (infrared absorption) spectrum (solvent: dry o-xylene; concentration of perhydropolysilazane: 10.2 g / l) has a wave number (cm ^-1 ) of 3390,
And 1180 NH-based absorption: 2170 Si-
Absorption based on H: Absorption based on Si-N-Si of 1040 to 800 was shown. FIG. 1 shows the IR spectrum.

Reference Example 2 [Synthesis of polymethyl (hydro) silazane] A gas blowing tube was placed in a four-necked flask having an inner volume of 500 ml.
A mechanical stirrer and dewar condenser were installed. After the inside of the reactor was replaced with deoxygenated dry nitrogen, methyldichlorosilane (CH ₃ SiHC) was placed in a four-necked flask.
l ₂ , 24.3 g, 0.221 mol) and 300 ml of dry dichloromethane. The reaction mixture is ice-cooled, and 20.5 g (1.20 mol) of dry ammonia is stirred while stirring.
Was blown together with nitrogen gas to perform ammonia decomposition.

After completion of the reaction, the reaction mixture was centrifuged and filtered. The solvent was removed from the filtrate under reduced pressure to obtain 8.79 g of polymethyl (hydro) silazane as a colorless liquid. The number average molecular weight of the product was 310 as measured by freezing point depression method (solvent: dry benzene).

A gas inlet tube, a thermometer, a condenser and a dropping funnel were attached to a four-necked flask having an inner volume of 100 ml, and the inside of the reaction system was replaced with argon gas. 12 ml of tetrahydrofuran and 0.189 g (4.71 mol) of potassium hydroxide were placed in a four-necked flask, and magnetic stirring was started. The above-mentioned 5.00 g of polymethyl (hydro) silazane and 50 ml of dry tetrahydrofuran were put into a dropping funnel, and this was dropped into potassium hydroxide. After reacting for 1 hour at room temperature, 1.60 g of methane iodide was added to the dropping funnel.
(11.3 mmol) and dry tetrahydrofuran 1
ml was added and this was added dropwise to the reaction solution. After reacting at room temperature for 3 hours, the solvent of the reaction mixture was removed under reduced pressure and dried.
-40 ml of hexane was added, centrifuged, and filtered. The solvent of the filtrate was removed under reduced pressure to obtain 4.85 g of polymethyl (hydro) silazane as a white powder.

The number average molecular weight of the produced polymer is 106
It was 0. IR (infrared absorption) spectrum [solvent: dry o-xylene; concentration of polymethyl (hydro) silazane:
43.2 g / l] is the wave number (cm ⁻¹ ) of 3380, and 1
Absorption based on 170 of N-H: 2140 based on the Si-H absorption: showed an absorption based on Si-CH ₃ 1250. FIG. 2 shows the IR spectrum.

Comparative Example 1 The perhydropolysilazane synthesized in Reference Example 1 was dissolved in xylene (20 wt%), and this was coated on a silicon wafer having a diameter of 4 inches and a thickness of 0.5 mm using a spin coater (3000 rpm). , 20 seconds) and dried at room temperature (10 minutes). The IR spectrum at this time was equivalent to the IR spectrum of perhydropolysilazane in FIG.
The weight of the polysilazane coating was 6.0 mg.
Subsequently, the silicon plate coated with the perhydropolysilazane was heated on a hot plate at 250 ° C. for 3 minutes.
At this time, a large amount of smoke was observed. The coating weight is 4.8m
g. Subsequently, it is placed in a dry air atmosphere at 400
Calcination was carried out at ℃ for 1 hour. The coating weight was 5.2 mg.

FIG. 3 shows the IR spectrum after firing. As compared with FIG. 1, absorption growth based on Si—O having a wave number (cm ⁻¹ ) of 1100 is observed, but unreacted polysilazane,
That is, absorption based on N-H of wave number (cm ^-1 ) 3350: absorption based on Si-H of 2190: 1024 to 82
A large amount of absorption based on Si-N-Si of 0 remains.

Comparative Example 2 The perhydropolysilazane synthesized in Reference Example 1 was dissolved in xylene (20 wt%), and this was coated on a silicon wafer having a diameter of 4 inches and a thickness of 0.5 mm using a spin coater (3000 rpm). , 20 seconds) and dried at room temperature (10 minutes). The IR spectrum at this time was equivalent to the IR spectrum of perhydropolysilazane in FIG.
The weight of the polysilazane coating was 6.0 mg.
Subsequently, the silicon plate coated with the perhydropolysilazane was heated on a hot plate at 250 ° C. for 3 minutes.
At this time, a large amount of smoke was observed. The coating weight is 4.8m
g. Subsequently, it was fired at 400 ° C. for 1 hour in an atmosphere of humidified air (80% relative humidity at 25 ° C.). The coating weight was 5.5 mg.

The stress of the coating film was measured by using Model. It was 2.5 × 10 ⁸ dyn / cm ^{2 as} measured by FLX2320 (room temperature). FIG. 4 shows the IR spectrum after firing. As compared with FIG. 1, the growth of absorption based on Si—O having a wave number (cm ⁻¹ ) of 1100 is observed, and unreacted polysilazane, that is, a wave number (cm ¹ )
^-1 ) Absorption based on NH of 3350: Si- of 2190
Absorption based on H: The absorption based on Si-N-Si of 1024 to 820 almost disappeared.

Example 1 The perhydropolysilazane synthesized in Reference Example 1 was dissolved in xylene (20 wt%), and this was coated on a silicon wafer having a diameter of 4 inches and a thickness of 0.5 mm using a spin coater (3000 rpm). , 20 seconds) and dried at room temperature (10 minutes). The IR spectrum at this time was equivalent to the IR spectrum of perhydropolysilazane in FIG.
The weight of the polysilazane coating was 6.0 mg.
This was then placed in a 2 liter glass desiccator with access door. Then, monomethylamine, steam and dry nitrogen were added to the desiccator at room temperature for 200 minutes each.
ml / min, 25ml / min, 2000ml / mi
Injected at a flow rate of n for 3 minutes. The water vapor has a capacity of 100
Dispensed using a ml glass bubbler. Subsequently, the sample was heated on a hot plate at 250 ° C. for 3 minutes. At this time, no fuming was observed. The coating weight was 6.6 mg. Subsequently, it was fired at 400 ° C. for 1 hour in a dry air atmosphere. The coating weight was 6.8 mg.

The stress of the coating film was measured by using Model. It was 5 × 10 ⁸ dyn / cm ^{2 as} measured by FLX2320 (room temperature). FIG. 5 shows the IR spectrum after firing. Compared to FIG. 1, absorption growth based on Si—O at a wave number (cm ⁻¹ ) of 1100 is observed, and unreacted polysilazane, that is, a wave number (cm ⁻¹ )
Absorption based on NH of 3350 and 1200: 2190
Based on Si-H: 1024-820 Si-N
The absorption based on -Si almost disappeared.

Example 2 The polymethyl (hydro) silazane synthesized in Reference Example 2 was dissolved in xylene (20 wt%), and the resulting solution was 4 inches in diameter.
It was applied to a 0.5 mm thick silicon wafer using a spin coater (3000 rpm, 20 seconds) and dried at room temperature (10 minutes). The IR spectrum at this time was equivalent to the IR spectrum of polymethyl (hydro) silazane in FIG. The weight of the polysilazane coating is 5.8 mg.
Met. This was then placed in a 2 liter glass desiccator with access door. Then, monomethylamine, steam, and dry nitrogen were added to the desiccator at room temperature at 200 ml / min, 25 ml / min, and 2000 ml, respectively.
The injection was performed at a flow rate of ml / min for 3 minutes. The water vapor was supplied using a glass bubbler having a capacity of 100 ml.
Subsequently, the sample was heated on a hot plate at 250 ° C. for 3 minutes. At this time, no fuming was observed. The coating weight was 6.1 mg. Subsequently, it was fired at 400 ° C. for 1 hour in a dry air atmosphere. The coating weight is 6.
3 mg.

The stress of the coating film was measured by using Model. It was ² × 10 ⁸ dyn / cm ^{2 as} measured by FLX2320 (room temperature). FIG. 6 shows the IR spectrum after firing. Compared to FIG. 1, absorption growth based on Si—O at a wave number (cm ⁻¹ ) of 1100 is observed, and unreacted polysilazane, that is, a wave number (cm ⁻¹ )
Absorption based on NH of 3350 and 1200: 2190
Based on Si-H: 1024-820 Si-N
The absorption based on -Si almost disappeared.

Example 3 The perhydropolysilazane synthesized in Reference Example 1 was dissolved in xylene (20 wt%), and the solution was applied on a silicon wafer having a diameter of 4 inches and a thickness of 0.5 mm using a spin coater (3000 rpm). , 20 seconds) and dried at room temperature (10 minutes). The IR spectrum at this time was equivalent to the IR spectrum of perhydropolysilazane in FIG.
The weight of the polysilazane coating was 6.0 mg.
Next, 10 g of triethylamine and 400 g of pure water were poured into a glass beaker having a capacity of 2 l, and the mixture was stirred well. And
A silicon plate with a polysilazane coating was suspended in the gas phase portion of this beaker at room temperature for 3 minutes, and brought into contact with steam generated from an aqueous triethylamine solution. Subsequently, this sample was
Heated on 0 ° C hot plate for 3 minutes. At this time, no fuming was observed. The coating weight was 6.1 mg. Subsequently, this was placed in a dry air atmosphere at 400 ° C. for 1
Fired for hours. The coating weight was 6.4 mg.

The stress of the coating film was measured by using Model. It was 8 × 10 ⁸ dyn / cm ^{2 as} measured by FLX2320 (room temperature). FIG. 7 shows the IR spectrum after firing. Compared to FIG. 1, absorption growth based on Si—O at a wave number (cm ⁻¹ ) of 1100 is observed, and unreacted polysilazane, that is, a wave number (cm ⁻¹ )
Absorption based on NH of 3350 and 1200: 2190
Based on Si-H: 1024-820 Si-N
The absorption based on -Si almost disappeared.

Example 4 The perhydropolysilazane synthesized in Reference Example 1 was dissolved in xylene (20 wt%), and this was coated on a silicon wafer having a diameter of 4 inches and a thickness of 0.5 mm using a spin coater (3000 rpm). , 20 seconds) and dried at room temperature (10 minutes). The IR spectrum at this time was equivalent to the IR spectrum of perhydropolysilazane in FIG.
The weight of the polysilazane coating was 6.0 mg.
Next, 30 g of n-pentylamine and 1000 g of pure water were poured into a glass beaker having a capacity of 2 l, and the mixture was stirred well. Then, the silicon plate with the polysilazane coating was immersed in the liquid in the beaker at room temperature for 3 minutes. Then, the sample was left at room temperature and dried well. Subsequently, this sample was
Heated on hot plate at 50 ° C. for 3 minutes. At this time,
No fuming was observed. The coating weight was 6.5 mg. Subsequently, it was fired at 400 ° C. for 1 hour in a dry atmosphere. The coating weight was 6.7 mg.

The stress of the coating film was measured by using Model. It was 6 × 10 ⁸ dyn / cm ^{2 as} measured by FLX2320 (room temperature). FIG. 8 shows the IR spectrum after firing. Compared to FIG. 1, absorption growth based on Si—O at a wave number (cm ⁻¹ ) of 1100 is observed, and unreacted polysilazane, that is, a wave number (cm ⁻¹ )
Absorption based on NH of 3350 and 1200: 2190
Based on Si-H: 1024-820 Si-N
The absorption based on -Si almost disappeared.

[0061]

According to the method for forming a siliceous ceramic film of the first aspect, the number average molecular weight having a skeleton composed mainly of the structural unit represented by the above general formula (I) is about 100 to 100.
After applying 50,000 polysilazane or a modified product thereof on a substrate, contacting with amines and water vapor at a temperature of 0 ° C. to 100 ° C., and then firing in a dry atmosphere. According to 450 ° C in dry atmosphere
In the following, a silica-based ceramic film having a dense and uniform surface can be obtained without being completely converted to silica and exerting an adverse effect on semiconductor elements and the like. Also, according to the method,
The amines scatter completely out of the film during firing.

The siliceous ceramic coating of claim 2 is
Since it is formed by the method of claim 1, it is excellent in abrasion resistance, heat resistance, corrosion resistance and the like, and is dense and homogeneous.

[Brief description of the drawings]

FIG. 1 is an IR spectrum of the perhydropolysilazane obtained in Reference Example 1.

FIG. 2 is an IR spectrum of the polymethyl (hydro) silazane obtained in Reference Example 2.

FIG. 3 shows the IR of the polysilazane-treated product obtained in Comparative Example 1.
It is a spectrum diagram.

FIG. 4 shows the IR of the polysilazane-treated product obtained in Comparative Example 2.
It is a spectrum diagram.

FIG. 5 is an IR of the polysilazane-treated product obtained in Example 1.
It is a spectrum diagram.

FIG. 6 shows the IR of the polysilazane-treated product obtained in Example 2.
It is a spectrum diagram.

FIG. 7: IR of the polysilazane-treated product obtained in Example 3
It is a spectrum diagram.

FIG. 8: IR of the polysilazane-treated product obtained in Example 4
It is a spectrum diagram.

Claims (2)

[Claims] 1. A compound represented by the following general formula (I): (In the formula, R ¹ , R ² and R ³ each independently represent a hydrogen atom, an alkyl group, an alkenyl group, a cycloalkyl group, an aryl group, or a group other than these groups which is directly bonded to silicon such as a fluoroalkyl group. Represents a group that is carbon, an alkylsilyl group, an alkylamino group, or an alkoxy group, provided that at least one of R ¹ , R ^2, and R ³ is a hydrogen atom. After applying polysilazane having a number average molecular weight of about 100 to 50,000 or a modified product thereof on a substrate, contacting with amines and water vapor at a temperature of 0 ° C. to 100 ° C., followed by firing in a dry atmosphere. Characteristic method of forming siliceous ceramic coating. 2. A siliceous ceramic film formed by the method according to claim 1.