JPS6197912A - Cvd equipment - Google Patents

Abstract

PURPOSE:To upgrade a CVD film and to easily selectively form a film by proceeding the light CVD and eliminating a reactive product in regular sequence through sequentially controlling both a light illuminating timing to a semiconductor and a gas supply timing into a CVD equipment. CONSTITUTION:In CVD process, a sequential controlling portion 20 get both a gas supply portion 14 and a light illuminating portion 19 into operation at the same time and also intermittently. In other words, after it supplies gas with opening a switch valve 13, it operates a light source 17 into illuminating light, stops operating for a moment and supplying a gas, the gas in a reaction chamber 1 is exhausted once. After gas supply and light illuminating are done again when some time passes after the exhaust, the predetermined film thickness of an SiO2 film 21 is obtained through repeating this several times. Owing to the exhaust between each portion through the intermittent light CVD reactions, a reactive product is eliminated from the reaction chamber. Therefore, a reactive product's contamination into the CVD film is prevented, the formation of the good quality CVD film is realized, and the requested film thickness is easily obtained as the film thickness is in proportional to number of repetition.

Description

[Detailed Description of the Invention] [Technical Field] The present invention relates to CVD (Chemical Vapor
Deposition method, especially high quality C
The present invention relates to a CVD apparatus that selectively forms a VD film by a tCVD method.

[Background technology]

CVD technology is used to form various thin films in the preparation of semiconductor devices such as IC and LSI, but in recent years, a method for selectively forming this thin film has been developed that directly eliminates the need for an etching process. Photochemical vapor deposition (CVD) methods have been used to form these materials. In other words, this photo-CVD method is a method in which a semiconductor substrate is set in a reactive gas atmosphere, and then an optical mask is used to irradiate light only on desired areas of the semiconductor substrate. This is a method in which a CVD film is selectively formed using source energy only in portions.

By the way, not only this photo-CVD method but also the CVo method in general,
As the CVD film is formed by reaction, other reaction products are generated and float within the CVD apparatus, and in some cases may adhere to the surface of the semiconductor substrate. When this reaction product adheres to the semiconductor substrate, it is mixed into the CVD film that is formed.
D The quality of the film will deteriorate. In particular, in recent semiconductor devices, the above-mentioned original CVD method is used as elements become smaller, and CVD films are formed only in minute parts and extremely thin, so CVDa due to the contamination of such reaction products A deterioration in the quality of the semiconductor device also affects the characteristics of the element, which is undesirable in terms of reliability of the semiconductor device.

An example of a detailed explanation of CVD technology is the electronic materials November 1983 special issue published by Kogyo Kenkyukai, 1983.
Published November 15, 2015, pages 69-74.

[Purpose of the invention]

An object of the present invention is to provide a CVD apparatus that can easily obtain high-quality CVDa even when forming thin films by the original CVD method, and can also easily perform selective film formation.

The above and other objects and novel features of the present invention include:
It will become clear from the description of this specification and the accompanying drawings.

[Summary of the Invention] A brief overview of typical inventions disclosed in the present application is as follows.

That is, a control unit is provided that sequentially controls the timing of supplying gas into the CVD apparatus and the timing of the original irradiation of the semiconductor substrate, so that the progress of 90VD and the removal of reaction products are performed in sequence. By setting the CV
A CVD film can be formed while the reaction products in the D apparatus are effectively removed, thereby improving the quality of the CVD film and facilitating the selective formation of the film.

[Example] Figure 1 shows an example of the CVD apparatus of the present invention.
For example, an example is shown in which an 8102 film is selectively formed on the surface of a silicon substrate. In the figure, a reaction chamber 1 is formed in a sealed state, and an exhaust port 2 is provided in the lower part of the reaction chamber 1 so that an exhaust pump 3 can be inserted to set the inside of the reaction chamber 1 to negative or positive. Also, in the reaction chamber 1, a support plate 5 for a silicon substrate (Weno) 4 is provided.
At the same time, a photomask 6 with a predetermined pattern is erected and supported in the immediate vicinity of the silicon wafer 4 (at the front position of the wafer 4).
Ru. Further, on the inner wall of the reaction chamber 1, a pair of large and small concave mirrors 7.8, which constitute a part of a light irradiation section 19 to be described later, are arranged facing each other.

Part of the upper part of the reaction chamber 1 is provided with a gas supply port 9, which is connected to gas sources 10, 11, and 12 of SiH, gas, N, 0 gas, or SiH4.02 gas. Further, an on-off valve 13 is interposed in the gas supply port 9, thereby forming a gas supply section 14.

Furthermore, a fine movement mechanism 15 is provided in a part of the reaction chamber 1, and one end of the original fiber 16 is attached to the fine movement mechanism 15, which is reciprocated vertically and horizontally as shown in the figure. The other end of the original fiber 16 is extended to a light source 17, and a filter spectrometer 18 is interposed in the middle of the fiber, and a filter spectrometer 18 is installed in the middle of the fiber, and a filter spectrometer 18 is inserted in the middle. A light irradiation unit 19 capable of irradiating the inside of the reaction-1 from one end of the fiber 16 is configured. A light source of white light or laser light is used as the light source.

The light source 17. The on-off valve 13 is connected to a sequence control section 20 and is configured to be operated in sequence according to a preset program.

According to the above configuration, if the opening/closing valve 13 is opened at the part where the inside of the reaction chamber 1 is evacuated by the exhaust pump 3, the S
IH4, N20. Each gas (S IH4, Ot ) is supplied into the reaction chamber 1 . - When the source 17 is operated, a predetermined source is irradiated into the reaction chamber 1 through the original fiber 16. Then, this light is reflected by a concave mirror 7.8 and passes through a photomask 6.
40 surfaces are irradiated. At this time, by operating the fine movement mechanism 15, the light is scanned up and down, left and right, and eventually scans the entire surface of the photomask 6, and is selectively irradiated onto the surface of the Ueno 4 according to the pattern shape of the photomask. . Therefore, as shown in FIG. 2, in the four parts of the wafer irradiated with light, the light energy changes S i H4+ N20 (02) → S i02+ H
,0+N2 reaction proceeds, and only at that site is Sin,
is deposited to selectively form SiQ film 21.

As this CVD progresses, as shown in the time chart in FIG. For example, the on-off valve 13 is opened to supply gas, and then the light source 17 is activated to irradiate the light. After this is temporarily stopped, the on-off valve 13 is closed to stop the gas supply, and the interior of the reaction chamber 1 is Exhaust the gas once. After some time has elapsed after evacuation, gas supply and light irradiation are performed again (1'-'), and by repeating this several times, a SiQ film 21 of a required thickness is obtained.

This good thing is SiQ! If film 21 film type 1, photo CVD
H2O produced along with 5iQ2 by the reaction.

N1 etc. are exhausted from the reaction chamber every time the exhaust is performed.
Since these products are removed from near the 810.
A film can be formed. In addition, in this formation, the 5102 film 21 is formed by repeating light irradiation for a predetermined time multiple times, so the thickness of the Sin film can be easily controlled according to the number of repetitions, and the desired film thickness can be achieved. can be easily obtained. Furthermore, since the optical fiber 16 is used in the light irradiation section 19, it is possible to simplify the equipment of the optical system, and there is less light loss (.), so that highly efficient film formation can be performed. Of course, optical scanning can also be easily performed.

〔effect〕

(1) A sequence control unit is provided in the original CVD apparatus that includes a gas supply unit and a light irradiation unit for the reaction chamber, and the sequence control unit is configured to operate the gas supply unit and the light irradiation unit in sequence. Therefore, the reaction products can be removed from the reaction chamber by performing the photoCVD reaction intermittently and exhausting the air in the valley.
High-quality CVD by preventing reaction products from entering the film
Achieve film formation.

(Since the 21CVD film is produced by repeating a short CVD reaction multiple times, the film thickness is proportional to the number of repetitions, making it easy to control the film thickness and obtain a desired film thickness.

(Since the original fiber is used for the 31 light irradiation section, it is possible to simplify the configuration of the optical system from the light source to the inside of the reaction chamber,
Optical scanning of the wafer can be easily performed.

(4) Since the original fiber is used, there is little optical loss.
Original CVD reactions can be performed with high efficiency.

Although the invention made by the present inventor has been specifically explained based on Examples, the present invention is not limited to the above Examples, and it is understood that various changes can be made without departing from the gist of the invention. It's no good. For example, various changes can be made to the internal structure of the reaction chamber, the original scanning method, etc., and it is also possible to directly selectively form a CVD film using a laser beam or the like.

[Application field]

In the above explanation, we have mainly explained the case where the invention made by the present inventor is applied to the technology for forming a C■DSiOz film, which is the field of application that formed the background of the invention, but it is not limited thereto. It can be applied as a device for forming an antinode formed by a CVD method such as a membrane.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional configuration diagram of an apparatus according to an embodiment of the present invention, FIG. 2 is an isolated diagram of essential parts of the wafer surface, and FIG. 3 is a time chart of sequence operations. 1°゛°reaction, 3...Exhaust port, 4...Ueno・
, 6... Photomask, 10-12... Gas source, 1
3...Opening/closing valve, 14...Gas supply section, 16...
Original fiber, 17... Light source, 19... Light irradiation part, 2
0...Sequence control unit, 21...CVD (Si
n,) membrane. 7D\, Figure 1/CH Figure 2Z/Figure 3

Claims (1)

[Claims] 1. A reaction chamber containing a semiconductor substrate and capable of setting the inside to a vacuum pressure, a gas supply unit supplying a reaction gas into the reaction chamber, and selectively applying light to the semiconductor substrate. A CVD apparatus comprising: a light irradiation section that irradiates the gas; and a sequence control section that sequentially controls the gas supply section and the light irradiation section. 2. The sequence control unit operates the gas supply and the light irradiation substantially synchronously, and during that time, increases the negative pressure in the reaction chamber to remove reaction products in the reaction chamber. Claim 1
CVD apparatus described in section. 3. The CVD apparatus according to claim 1 or 2, wherein the light irradiation section is formed by connecting the reaction chamber and the light source with an optical fiber.