JPS59112487A - Manufacture of bubble memory device - Google Patents

Abstract

PURPOSE:To cause no electric corrosion failure extending over a long period by dissolving polydialkoxysilane prepolymer (PDAS) in an organic solvent whose boiling point is >=110 deg.C, and using a PDAS solution obtained by expelling hydrogen chloride by specified temperature and reduced pressure. CONSTITUTION:PDAS obtained by hydrolyzing tetraalkoxysilane under the existence of hydrogen chloride and bringing it to polycondensation is dissolved in an organic solvent whose boiling point is >=110 deg.C, and from this solution, hydrogen chloride is expelled at <=40 deg.C temperature and under reduced pressure of <=5mm.Hg pressure, and an obtained PDAS solution singly, or a solution obtained by mixing polysilsesquioxane prepolymer in said solution is applied onto a metallic film on a garnet substrate and cured, and an insulating material and/or a protective film of silicone resin is formed. By the insulating layer or the protective film formed in this way, the operation failure due to an electric corrosion failure can be prevented extending over a long period.

Description

DETAILED DESCRIPTION OF THE INVENTION (1) Technical Field The present invention relates to a method for manufacturing a bubble memory device in which a silicone resin solution is applied and cured as an interlayer insulation material and/or a protective film.

(2) Background of the technology Bubble memory devices require a high level of reliability over a long period of time, but if a small amount of electrolyte is present in the insulating material or protective film used for them, defects due to electrolytic corrosion will occur and the lifespan will be shortened. do.

(3) Prior art and problems PDA, which is a hydrolyzed polycondensate of tetraalkoxysilane, is used as an insulating material or protective film for pulp memory devices.
A 5IO2 film is formed by applying a solution of S and heating it.

Tetraalkoxysilane 5i(oa)4 (wherein, R
(CnH2n+4, such as methyl, ethyl, propyl, butyl, etc.) is hydrolyzed and polycondensed in the presence of a reaction accelerator acid as shown in the following formula.

5l(OR)4+2H20→81(OR)2(OH)2
+2ROH(1)n S 1 (OR) 2 (OH)
2→HO'ES i (OR) 209n H+ (
n-1) H2O (2) In addition to the reaction of formula (2), reactions such as dealcoholization, conversion to mi 5i (OH) groups, and gelation tend to occur.

PDAS is always dissolved in an organic solvent for reaction or storage in order to prevent gluing.

The reaction accelerator acid is hydrochloric acid, and 0.05 to 0.5 g of hydrogen chloride is often added to the weight of the monomer. This is to take advantage of the fact that hydrogen chloride can be removed by volatilization during heat curing of the coating film. However, in long-term bias tests, the aluminum wiring and permalloy film appear to be electrolytically corroded, resulting in defects. This is thought to be due to a trace amount of hydrogen chloride remaining.

Removal of hydrogen chloride is generally possible by washing with water. However, in PDAS, the mi5i (OR) group is easily converted to =st (oH) group, and when this group increases, it may be glued or PDAS may be distributed to the washing water phase. If alcohol is used as a solvent, it will be lost in the washing aqueous phase, so alcohol cannot be used to remove hydrogen chloride.

Note that volatile hydrogen chloride can be separated by distillation, but this is not possible because PDAS will be glued if the distillation temperature is increased.

As the coating liquid for the surface protection material, not only PDAS alone but also a mixed solution with Sen's silicone resin can be used. The silicone resin to be mixed is, for example, a hydrolyzed product of alkyltrialkoxysilane (Japanese Patent Application Laid-Open No. 1989-1999).
81928 and JP-A-48-26822),
Polysilsesquioxane prepolymer (Unexamined Japanese Patent Publication No. 54-1
71005), the latter can be uniformly protected or coated by using butyl cellosolve acetate, ethyl cellosolve acetate, methyl cellosolve acetate, n-butyl alcohol (see JP-A-55-158114). The present inventors disclose that a coating film can be applied.

(4) Purpose of the Invention An object of the present invention is to provide a method for manufacturing a bubble memory device in which a protective film and/or an interlayer insulation material for wiring are formed without causing electrolytic corrosion defects over a long period of time.

(5) Structure of the Invention The above-mentioned object of the present invention is to provide a method for manufacturing a group memory device using a silicone resin as an interlayer insulation material and/or a protective film, which comprises hydrolyzing tetraalkoxysilane in the presence of hydrogen chloride. Polycondensation is performed to form a polydialkoxysilane prepolymer (PDAS), and this PDAS has a boiling point of 1
Dissolve in an organic solvent at a temperature of 10°C or higher, and heat the resulting solution to a temperature of 40°C.
Hydrogen chloride is removed by reducing the pressure to a pressure of 5 Hg or less, and the obtained PDAS solution alone or a solution obtained by mixing polysilsesquioxane prepolymer with this solution is applied to the metal film on the garnet substrate and cured. This can be achieved by a method for manufacturing a bubble memory device characterized by forming an insulating material and/or a protective film of silicone resin.

The PDAS dissolved in the organic solvent is advantageously freed from hydrogen chloride under a reduced pressure of 0.5 to 3.0 mm.

At this time, it is preferable to expel hydrogen chloride at a temperature of 5 to 28°C.

As the organic solvent used, it is convenient to use methyl cellosolve acetate, ethyl cellosolve acetate, butyl cellosolve acetate, n-butyl alcohol, or a mixed organic solvent containing any of them.

Three types of solutions were prepared by combining 100 parts by weight of an ethyl alcohol solution of 0.2% HC1, 15% PDAS with 150.130.100 parts of methyl cellosolve acetate, ethyl cellosolve acetate, and butyl cellosolve acetate, respectively, at a pressure of 3.0. It was distilled under reduced pressure at mxHg and 25°C to obtain a push liquid in which chloride ions could not be detected with silver nitrate. The remaining amounts of cellosolve acetate were 48, 76, and 98, respectively, of 1 inch added at the beginning. The boiling points of these cellosolve acetates are 144.5 to 145, respectively.
．． 1°C, 1563°C, and 191.5°C, and is a conventionally known PDAS solvent. When using butyl alcohol with a boiling point of 117.7°C as a solvent, the remaining amount after vacuum distillation with silver nitrate until chloride ions can no longer be detected is 45%.
% p can be used in the present invention.

However, isobutyl alcohol, which has a boiling point of 107.9° C., is not suitable because the residual amount decreases to 25% in the same treatment.

As organic solvents with a boiling point of 110° C. or higher, in addition to the above-mentioned alcohol-based and cellosolve acetate-based solvents, cellosolve-based and ketone-based solvents dissolve PDAS. When mixed with the polysilsesquioxane prepolymer, it is preferable to use cellosolve solvents in addition to the above, since ketone solvents have a problem in compatibility with the ax primer. Note that in the case of PDAS treatment alone, aromatic hydrocarbons mixed with ketones and alcohols can be used.

In the present invention, there are no particular limitations on the polysesquioxane prepolymer that can be used in combination with PDAS. This prepolymer is prepared by dissolving R' S ICZ3 in, for example, methyl isobutyl ketone, adding a hydrochloric acid acceptor such as triethylamine, and then adding water to give R'5i(OH)3. R'5I(OH)3 is polycondensed by heating, washed with water, concentrated, and a precipitant such as methyl alcohol (kf) is added to obtain a white powder of HO+R'S i Ot 5+nH. The polycondensation of R'5I(OR)3 is promoted by adding hydrochloric acid, but when starting from R' S i Cl3, Hct
There is no need to do so as it includes

The molecular structure of polysilsesquioxane prepolymer is R
' Starting from S I C13, it has a relatively complete ladder structure as shown in formula (3).
), and starting from R'5i(OR)3, the formula (4
) (Shibe Takeda, Proceedings of the 44th Autumn Annual Meeting of the Chemical Society of Japan, It, p. 582, 1982).

In the formula, R is a lower alkyl group or a partially hydrogen group.
R' is a lower alkyl group, and k is a phenyl group. ms
n is a positive integer, and m is often 10 or less, including 0.

In the present invention, these polysilsesquioxane prepolymers can be mixed with PDAS, and there are many limitations on the mixing ratio. In any case, POAS contains hydrogen chloride. Therefore, in order to use it as a protective film for a bubble memory device or as an interlayer insulation material for wiring, it is necessary to drive out hydrogen chloride during polycondensation. Note that it is desirable to use it in combination with an inorganic oxide film formed by other vapor phase growth methods. For example, the resin layer of the present invention may be formed on aluminum wiring, and a civil vapor phase growth oxide film may be formed thereon, or vice versa. Alternatively, the resin layer of the present invention can be formed on a vapor-phase growth film formed between wiring layers by a lift-off method.

(6) Examples and Comparative Examples Weight average molecular weight (hereinafter referred to as Mw, the value converted to standard polystyrene by glu-ya-meation chromatography)
is 5400, the functional groups are ethoxy groups and hydroxyl groups, and the molar ratio thereof is about 1:1. 15.5% by weight of PDAS and 2% by weight of HClO, in a weight ratio of 3: 100g of the mixed solution of 2 (hereinafter referred to as PDAS solution-■) was placed in a 500 g eggplant-shaped flask, and 100 g of the mixed solution of 84.
Added 5g.

The flask was set at a 45° inclination, connected to a rotary evaporator, and rotated at 60 rpm.

Next, the flask was placed in a water bath with a bath temperature of 25° C., and the pressure was reduced to 2.0 Hg using a vacuum pump, and the pressure was reduced for 4 hours.

Add solvent s to the dry ice/ethyl alcohol trap.
6. The residual solution was collected at 98.4 F, and 1.6 I of n-butyl cellosolve acetate was added thereto to obtain a PDAS solution-■.

Pour this PDAS solution-111,F into a test tube and add 0.1
When 2 g of a wt % silver nitrate aqueous solution was added and the mixture was shaken, a white gluide eventually adhered to the tube wall of the organic phase, and the aqueous phase became silvery brown, but no white precipitate was formed. Further, the remaining PDAS solution (1) was extracted and washed with water, burned in a flask, and an attempt was made to detect chlorine using the mercuric thiocyanate method, but the detection limit was 10 ppm or less.

When 11 g of Senga PDAS solution was placed in a test tube and 1 drop of 0.1% by weight silver nitrate was added and shaken, it became cloudy. Furthermore, when 3 g each of water and n-butyl cellosolve acetate were added, most of the cloudiness was transferred to the aqueous phase, and the PDAS glumate was transferred to the organic phase.

10 on the garnet substrate on which the epitaxial layer was formed.
A PDAS solution was applied to the wafer on which a 0OX SjO□ layer and a 4000X aluminum wiring layer were formed.
Spin coating at 112,000 rpm for 30 seconds, 300°C,
Heat treated in nitrogen for 60 minutes. Next is 800X 5I02
The layer was sputtered and further heated at 4000 x/'
A P-malloy film was formed and patterned, and then a PDAS solution -■ was again spin-coated in the same manner, and then 10000
A bubble memory device was obtained by forming a 5i02 layer of X in four zigzag shapes and opening a window for taking out the electrodes. This device was subjected to a bias test at a temperature of 80° C. and a relative humidity of 95% with a voltage of 24 V applied for 1000 hours, but no malfunction occurred.

Comparative Example I 300% of PDAS solution -■ instead of PDAS solution -■
A bubble memory device was obtained in the same manner as in Example 1, except that spin coating was performed using Orpm for 30 seconds.

When this bubble memory device was subjected to a bias test in the same manner as in Example 1, a malfunction occurred, which was thought to be caused by the deterioration of the l-rimalloy. In addition, a bubble memory device in which PDAS solution -2 was applied and heat-treated only between wiring layers exhibited malfunction after 500 hours of a similar bias test.

Example 2 PDAS with Mw of 3100 and functional groups of methyl group and hydroxyl group in a molar ratio of about 2:1 11.4 times:! i! PDAS solution-I, which is a mixed solution of methyl ethyl ketone and methyl alcohol at a weight ratio of 7:3 containing 0.05% by weight of HCl [20 g of n-butyl cellosolve acetate and 6 g of n-butyl alcohol were added to 1100 g; The PDAS solution was distilled under reduced pressure in the same manner as in Example 1.

Into this solution was added a polysesquinone having a Mw of 10,600 and represented by the formula (4), where R' is a methyl group, R is an ethyl group and a hydroxyl group, the molar ratio is about 1:1, and the average value of m is 2.1. Oxane prepolymer 11.4. ! i+ and 5.8 g of n-butyl alcohol were added and dissolved to obtain a mixed silicone solution -■. No chloride ions were detected in this liquid when tested using the same mercuric thiocyanate method as in Example 1.

(13) Using this mixed silicone solution, 6000 rpm
Bubble memo IJ@Ff was obtained in the same manner as in Example 1, except that spin coating was performed for 90 seconds, and no defects occurred even after 1000 hours of the bias test of Example 1.

Comparative Example 2 A mixed silicone solution -■ in which a polysesquioxane prepolymer was mixed was used in the same manner as in Example 2, except that PDAS solution -■ was used instead of PDAS solution -■. No chloride ions could be detected in this solution when tested using the mercuric thiocyanate method.A bubble memory device similar to that in Example 2 was manufactured and subjected to the bias test of Example 1, and electrolytic corrosion was observed after 120 hours. There has occurred.

(14)

Claims (1)

[Scope of Claims] 1. A method for manufacturing a pulp memory device using silicone resin as an interlayer insulation material and a protective film, which comprises hydrolyzing and polycondensing tetraalkoxysilane in the presence of hydrogen chloride. Alkoxysilane prepolymer (hereinafter P
PDAS (referred to as DAS) is dissolved in an organic solvent with a boiling point of 110°C or higher, and the resulting solution is reduced to a temperature of 40°C or lower and a pressure of 5+n+nHg or less to remove hydrogen chloride, and the resulting PDAS solution alone or this solution is A method for manufacturing a bubble memory device, characterized in that a solution containing a polysilsesquioxane prepolymer is applied to a metal film on a garnet substrate, and the solution is applied to a metal film on a garnet substrate to form an insulating material and/or a protective film of silicone resin. . 2. PDAS O dissolved in the organic solvent, 5-3.0
2. The method according to claim 1, wherein hydrogen chloride is removed under reduced pressure of mHH. 3. The manufacturing method according to claim 1 or 2, wherein hydrogen chloride is expelled at a temperature of 5 to 28°C. 4. The organic solvent is methyl cellosolve acetate, ethyl cellosolve acetate, n-butyl cellosolve acetate, methyl cellosolve, ethyl cellosolve, or n-
The manufacturing method according to any one of claims 1 to 3, which is dithyl alcohol.