JPH0761853B2 - Method and apparatus for forming silicon oxide film - Google Patents

Description

TECHNICAL FIELD The present invention relates to a method and apparatus for converting an organosilicon film formed by coating on the surface of a substrate into a silicon oxide film.

(Prior Art) In recent years, miniaturization of multi-layer wiring is also required for higher integration of LSI, and for this purpose, the underlying layer must be planarized with a stable material.

Therefore, conventionally, in order to flatten the underlayer, a liquid organosilicon polymer is uniformly applied on the substrate and is oxidized to form a stable silicon oxide film.

That is, the organosilicon polymer has the structural formula shown in FIG. 4 (A), for example, and is oxidized to form a stable silicon oxide film. However, it is difficult to completely release the R group, that is, the alkyl group, the aryl group, etc., and when the silicon oxide film is etched with the R group remaining, the carbon atoms of the R group cause variations in the etching characteristics or cracks. May occur. Therefore, in order to obtain a stable silicon oxide film (SiO ₂ ) shown in FIG. 4 (B) by removing the R group, as disclosed in JP-A-59-111333, organosilicon (SiOR) is irradiated with ultraviolet rays. There is known a method of irradiating a silicon oxide film to convert it into a silicon oxide film (SiO ₂ ).

(Problems to be Solved by the Invention) According to the above-mentioned method, a part of oxygen (O ₂ ) in the air is converted to ozone (O ₃ ) having a strong oxidizing power by ultraviolet rays, and R
The group is oxidized to form stable SiO ₂ , but it has a disadvantage that it takes a long time to be fully stabilized.

(Means for Solving the Problems) In order to solve the above problems, the present invention provides a process chamber that accommodates a substrate on which an organosilicon film is formed, and opens a passage for supplying ozone to the process chamber or outside the process chamber. An ultraviolet lamp for irradiating the substrate with ultraviolet rays was provided.

(Function) The R group in the organosilicon is cut in its bond by the ultraviolet energy and the oxidation function, and changes into a stable silicon oxide film (SiO ₂ ).

(Example) Below, the Example of this invention is described based on an accompanying drawing.

FIG. 1 is an overall view of the apparatus for forming a silicon oxide film according to the present invention. The forming apparatus is provided with casters 2 on a base 1 so as to be movable, and a support plate 4 is mounted on the base 1 via columns 3a. The table 5 is provided on the support plate 4 via the columns 3b.

A vertical bracket 6 is fixed on the support plate 4, and a table 9 is moved up and down by an elevating member 7 provided above the bracket 6.

An upper surface of the stage 9 serves as a mounting surface of the substrate W, and a coating film of liquid organosilicon polymer is formed on the upper surface of the substrate W by a spinner device. Further, below the mounting surface of the substrate W, a heating member 10 such as a hot plate capable of controlling the temperature is embedded, and a flange portion 9a extending outward is formed on the stage 9 at a position lower than the heating member 10. The flange portion 9a when 9 rises and enters the opening 11 formed in the table 5 from below.
The upper surface abuts the seal member 5a provided on the lower surface of the table 5,
The lower part of the opening 11 is airtightly closed.

The upper part of the opening 11 is hermetically closed by a transparent plate 12 such as a quartz plate, and a processing chamber S is formed between the transparent plate 12 and the stage 9. The processing chamber S is open to the outside air through the exhaust passage 13 and the bellows-shaped flexible tube 14 formed in the table 5, and the ozone supply passage 16 formed in the table 5 is opened in the processing chamber S. An ozone generator 17 is connected to the supply passage 16.

An ultraviolet lamp 19 located above the transparent plate 12 is mounted on the table 5 via a support block 18. As the ultraviolet lamp 19, for example, a low-pressure mercury lamp, a high-pressure mercury lamp, an ultra-high-pressure mercury lamp, a xenon lamp or the like is used, and its shape is arbitrary such as a linear shape or a curved shape. Further, the ultraviolet lamp 19 is housed in a cover, and cooling water from a cooling device 20 incorporating a circulation pump mounted on the base 1 is supplied into the cover through a pipe (not shown). A power supply 21 for lighting the ultraviolet lamp 19 and energizing the heating member 10 is arranged next to the cooling device 20, and a housing 22 and an illuminance monitor 23 whose lower surface is a mirror surface are arranged above the ultraviolet lamp 19. I have set up.

A processing method for stabilizing the organosilicon polymer formed on the surface of the substrate W using the apparatus having the above-described structure will be described.

First, the stage 9 is lowered from the state shown in FIG. Then, in this state, the power supply 21 is turned on and the start switch is turned on. Then, the heating member 10 rises in temperature and the ultraviolet lamp 19 is turned on.

After that, the illuminance monitor 23 indicates that the illuminance of the ultraviolet lamp has reached a predetermined value (for example, 20 mW / cm ² at a wavelength of 253.7 nm), and the temperature of the heating member 10 has a predetermined value (for example, 100 to 1200 ° C.).
When it is detected that the cooling water has reached a predetermined value, the substrate W is placed on the stage 9 which is in a lowered state, and the stage 9 is raised to bring the substrate W into the processing chamber S.
And the processing chamber S is airtightly closed.

Then, a gas containing 1 vol% or more of ozone gas is supplied to the processing chamber S through the ozone supply passage 16, and then the organosilicon polymer on the surface of the substrate W is irradiated with ultraviolet rays. This processing time is usually about 2 minutes.

When the above process is completed, the ozone supply passage 16 is closed, the stage 9 is lowered, the substrate W is taken out, and it is stored in the cassette.

FIG. 2 is a sectional view showing a main part of an apparatus according to another embodiment, and the same members as those in the above embodiment are designated by the same reference numerals.

In this embodiment, instead of the transparent plate 12 of the above embodiment, a chamber 24 made of synthetic quartz covers the opening 11 of the table 5, and an ultraviolet lamp 19 is arranged in the chamber 24. An illuminance monitor 23 and an ozone introducing pipe 25 are attached to the chamber 24.

In the illustrated example, the stage can be moved up and down, but the stage 9 is integrated with the table 5, and the substrate W is loaded onto the stage 9 from the side by a transport mechanism such as a conveyor. You may do it.

(Effects of the Invention) FIG. 3 is a graph showing the relationship between the amount of ozone required to release the organoradicals when the heating member is held at 200 ° C. and the treatment time. According to the invention, the time required for stabilization is greatly shortened in proportion to the ozone concentration. Therefore, it is desirable that the ozone concentration be as high as possible, but in reality, the concentration of ozone generated by a commercially available ozone generator is about 15%, but this is still sufficient. Further, it can be stabilized even if the processing temperature is lowered, and the multilayer wiring of LSI can be miniaturized.

[Brief description of drawings]

FIG. 1 is an overall view of a silicon oxide film forming apparatus according to the present invention, FIG. 2 is a cross-sectional view of an essential part of another embodiment, FIG. 3 is a graph showing the relationship between the amount of ozone and processing time, and FIG. (A) and (B) are structural formulas of the organosilicon polymer and the silicon oxide film. In the drawing, 5 is a table, 9 is a stage, 10 is a heating member, 12 is a transparent plate, 13 is an exhaust passage, 16 and 25 are ozone supply passages, 19 is an ultraviolet lamp, and 24 is a chamber.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Akira Hashimoto 474-6 Kuriki-cho, Isogo-ku, Yokohama-shi, Kanagawa Prefecture (72) Toshihiro Nishimura 5-19-4 Oda, Kawasaki-ku, Kawasaki-shi, Kanagawa

Claims (3)

[Claims] 1. A substrate on which an organosilicon film is formed is set in a processing chamber, a gas containing 1 vol% or more of ozone is introduced into the processing chamber, and the organosilicon film is irradiated with ultraviolet rays while heating the organosilicon film. A method for forming a silicon oxide film, characterized in that a silicon oxide film is used. 2. A table having an opening, a stage for mounting a substrate which seals the opening and is provided with a heating member, a transparent plate which seals the upper part of the opening, and an upper part of the transparent plate. Apparatus for forming a silicon oxide film, which is provided with an ultraviolet lamp disposed in the chamber, a vacuum exhaust passage, and an ozone supply passage. 3. A table having an opening, a substrate mounting stage that seals the opening and includes a heating member, a chamber fixed on the table so as to cover the opening, and the chamber. An apparatus for forming a silicon oxide film, comprising: an ultraviolet lamp disposed inside; an exhaust passage inside a chamber; and an ozone supply passage for introducing ozone into the chamber.