JPH0456134A - Manufacture of sio2 film using spin-on-glass method and coating agent thereof - Google Patents

Abstract

PURPOSE:To entirely eliminate cracks of an SiO2 film and to improve yield of an Si substrate by using coating agent mixed with fine particles such as silica in addition to normal silanol. CONSTITUTION:0.5% of silica particles having 0.3mum of particle size is mixed with coating agent in which 5% of silanol is added to alcohol solution of organic solvent as silicon compound. An Si substrate is coated with the mixture in thickness of 0.2mum, then preliminarily dried at 100, 150 and 250 deg.C respectively for five min, and further dried at 430 deg.C for 30min. As a result, crack occurrence ratio at the film becomes '0'.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a method for manufacturing an SiO2 film using a spin-on glass method and a coating agent therefor.

<Prior art> When manufacturing semiconductor devices such as LSIs, the spin-on glass (hereinafter abbreviated as SOG) method is a relatively popular method for producing a 5iOz film on the surface of a Si substrate at low temperatures. It is widely used because it is simple.

In this SOC method, a coating agent prepared by dissolving a silicon compound represented by R75i(OH)<-1l (silanol) in an organic solvent such as alcohol is applied to a Si substrate, and then heated to remove the solvent. A SiO2 film is produced by a dehydration condensation reaction together with the removed material.

<Problem to be solved by the invention> By the way, in this SOG method, SiO
! There is a drawback that the film cracks, so in order to avoid this, for example, the amount of coating agent applied at one time should be adjusted to 0.1~0.3
If a thicker film is required, it has been proposed to obtain a predetermined film thickness by repeating coating and heating multiple times (for example, Japanese Patent Application Laid-Open No. 51-6047
(See Publication No. 9).

However, even this multiple application method cannot completely prevent cracks, so a method of adding a small amount of phosphorus to the coating agent is also used, but 5iOz#, which contains phosphorus, is hygroscopic. This has been a cause of deterioration in the characteristics of semiconductor devices (see, for example, Japanese Patent Laid-Open No. 64-25543).

An object of the present invention is to provide a method for manufacturing a 5iOt film using a spin-on glass method that solves the above-mentioned problems, and a coating agent for the same.

<Means for solving tXB> The characteristics of the method for manufacturing a SiO□ film of the present invention are as follows:
When a SiO□ film is formed on the surface of a Si substrate by low-temperature heating using the spin-on-glass method, a coating agent containing fine particles such as silica is used in addition to ordinary silanol.

Furthermore, the coating agent of the present invention used here is characterized by containing silica particles with a particle size of 0.005 to 0.1 μm in the coating agent prepared by dissolving a silicon compound in an organic solvent. It is a mixture of 0.1 to 5%.

Effect> According to the present invention, the coating agent has no warping force (
Since SiO□) particles are added, when the coating agent is applied to the surface of the Si substrate and heated for dehydration condensation, when the SiO□ film shrinks and cracks are about to form, the added silica The particles act as a resistance against cracks and can prevent cracks from occurring.

The reason for limiting the particle size and mixing ratio of silica added to the coating agent will be explained below.

The average particle size of silica should be 0.005 to 0.10 μm; The lower limit of 0.005 μm is a restriction in manufacturing silica fine particles, and it is preferable that the particle size is as small as possible if it is possible to manufacture it. .

In addition, the upper limit is set to Q and 10 μm, which is 0.10 tIm.
This is because if the above particles adhere to the convex portions of the Si substrate, they will become a hindrance to patterning.

- The mixing ratio of silica was set in the range of 0.1 to 5%: The lower limit was set at 0.1% because if the mixing ratio is lower than 0.1%, there is no effect in preventing cranking. The reason why the upper limit was set at 5% is that if the mixing ratio is higher than 5%, the clay content of the coating agent will increase and the uniformity of the film thickness will deteriorate.

Note that the same effects as in the case of silica can be obtained by using alumina (Al□O3), titania (TiO□), zirconia (ZrO□), etc. other than silica.

<Example> Yes! A coating agent containing 5% silanol as a silicon compound added to an alcoholic solution containing a particle size of 063 μm.
After mixing 0.5% of the following silica particles and applying it to a thickness of 0.2 μm on the surface of a Si substrate, 100°C, 150°C, 2
Pre-dry at 50°C for 5 minutes each, then dry at 430'C.
As a result of drying for 7'30 minutes, the result was 5iO8P/l! The incidence of cracks was O.

On the other hand, for comparison, 5 silanol was added to the alcohol solution.
When a conventional coating agent containing 10% of SiO2 was applied to the surface of a Si substrate under the same conditions as in the above example, preliminary drying, and drying were performed, the cracking rate of the SiO□ film was as high as 3%.

<Effects of the Invention> According to the present invention, by adding silica particles to a conventional coating agent, sio! ll! It is possible to completely eliminate the occurrence of J cracks, and it is possible to improve the yield of Si substrates.

Claims (1)

[Claims] 1. Si is heated at a low temperature using the spin-on glass method.
A method for producing an SiO_2 film using a spin-on-glass method, which is characterized in that when forming a SiO_2 film on a substrate surface, a coating agent mixed with fine particles such as silica is applied and then heated. 2. It is made by mixing a coating agent prepared by dissolving a silicon compound in an organic solvent with 0.1 to 5% of silica, etc., which are considered to be fine particles with a particle size of 0.005 to 0.1 μm. A special coating agent for spin-on glass.