JPS63168027A - Film forming device - Google Patents

Abstract

PURPOSE:To prevent the intensity of incident light from declining due to the film formed on a window by a method wherein, within a device to form film by photoirradiation through a phototransmitting window, the phototransmitting window is provided with a heating mechanism to heat the window during the film formation process. CONSTITUTION:Reactive gas is led into a reaction chamber 11 from a gas leading-in port 15 to maintain the chamber 11 at specified vacuum degree making use of a discharge pump 14. Then, a substrate 12 is heated and irradiated with light from a light source 17 through a phototransmitting window to form a film. At this time, a window 16 is heated by heating bodies 21. In such a constitution, the denseness of film formed on the window 16 can be increased so that the scattering of incident light due to the formed film may be prevented from occurring also preventing the intensity of light irradiating the reaction chamber 11 from declining to enable the film to be formed for a long time.

Description

[Detailed description of the invention] Industrial applications The present invention relates to a film forming apparatus using light irradiation.

2. Description of the Related Art A conventional film forming apparatus is an optical Chemical'V system as shown in FIG.
An apor DepOgitiOn (hereinafter referred to as photoCVD) device is used.

In the photo-CVD apparatus shown in FIG. 6A, a reaction chamber 11 is provided with a substrate holder 13 capable of heating a substrate 12, and a source gas is introduced through an exhaust pump 14 and a source gas inlet 15 to maintain a predetermined degree of vacuum. Light irradiation is performed through a light transmission window 16 (hereinafter referred to as window) using a light source 17 such as a low pressure mercury lamp to form a film. Note that a rubber gasket 18 is sandwiched between the reaction chamber 11 and the window 16.

Problems to be Solved by the Invention However, when film formation is performed using the optical CVN device as described above, film formation also occurs on the window 16, and as the window becomes cloudy, the film formation speed decreases due to a decrease in the intensity of incident light. However, there is a problem that the film will eventually stop forming.0 To prevent this problem, as shown in Figure 5, the window 1
It has been proposed that perfluorinated polyether 19 be applied to the surface of 6 to prevent formation on the window (Japanese Patent Application Laid-Open No. 57-154).
Publication No. 839). However, with this method, there remains concern about contamination of the formed film with the perfluorinated polyether, and there is also the problem that the film formed on the perfluorinated polyether 18 is likely to peel off and re-adhere to the substrate.

Means for Solving the Problems In order to solve the above-mentioned problems, the present invention provides a heating mechanism in the light transmission window to heat the window during film formation.

Effects of the present invention With the above-described configuration, the film formed on the window is improved in density, thereby preventing scattering of incident light by the formed film and preventing a decrease in the intensity of light irradiated into the reaction chamber. It enables film formation.

Example (Example 1) FIG. 1 is a schematic diagram showing an example of the film forming apparatus of the present invention. In the first reactor, 11 has a substrate holder 13 that can heat the substrate 12 in the reaction chamber, maintains the degree of vacuum with an exhaust pump 14 and a gas inlet 16, and passes low-pressure mercury through the entire light transmission window 16 made of synthetic quartz. Light from a lamp light source 17 is introduced. Note that there is a rubber gasket 1 between the reaction chamber 11 and the window 16.
8 (hereinafter referred to as an O-ring) to maintain the vacuum. 21 is a heating element that can heat the window 16, and 22 is a cooling device.

FIG. 1 is a view of the state of the window 16 viewed from the light source 17 side. The heating body 21 and the cooling device 22 are arranged as shown in the figure.

An example of forming a silicon oxide film (hereinafter referred to as S-o2) using the apparatus configured as described above will be described below.

SiH4:N20=1: as a gas introduced into the reaction chamber 11
The gas is introduced from the gas inlet 15 at a flow rate ratio of 50, and maintained at a vacuum degree of i 1 Q Torr by the exhaust pump 14. Board 1
2, the single-crystal Si was heated to 350'C, and the low-pressure mercury lamp of the light source 17 was heated to 15 mW at a wavelength of 254 nm on the substrate.
Irradiation is performed at an intensity of /i to form a film. FIG. 2 shows the formed film thickness with respect to the forming time when the window 16 was heated to about 150° C. by the heating element 21 at this time.

For reference, the case where the window 16 is not heated is also shown. In this way, the film thickness after 13 hours of formation was approximately 1.4
You can improve it twice as much.

(Example 2) FIG. 3 is a schematic diagram showing an example of the pond of the film forming apparatus of the present invention. The device configuration is the same as in Example 1, with a gas inlet 152
L and a window 16 are provided with a purge gas inlet 15b. The light source 17 irradiates the substrate 12 with an excimer laser of MURF in parallel. The shape of the heating body 21 shown in FIG. 3 is such that it can be heated by passing a current through it from 212L.

Silicon nitridation (hereinafter referred to as SiN) using the device with the above configuration
An example of forming a film will be described below.

A flow ratio of SiH4:NH4-1:40 was supplied to the reaction chamber 11 through the gas inlet 152L, red gas was supplied through the purge gas inlet 15b, and the degree of vacuum was raised to 1o using the exhaust pump 14.
Keep at Torr. Light with a laser power of about 8 watts is applied from an ArF excimer laser light source 17 in parallel onto the single crystal and substrate 12 heated to 300'C to form a SiN film.

The thickness of the S-N film is about 16QQnffl, and it takes about 3
Laser irradiation was performed for 0 minutes. FIG. 4 shows the change in film thickness with respect to the formation cycle at this time. The heating temperature of the window 16 is about 200'C, and the case without heating is also shown for reference. In this manner, by heating the window, the forming cycle can be extended approximately twice as long as when the window is not heated.

Effects of the Invention As described above, according to the present invention, with an extremely simple configuration of installing a heating mechanism for the light entrance window, a decrease in the intensity of incident light due to the film formed on the window can be prevented, and it can be used for a long time in optical CVD. It is extremely useful for practical purposes.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram of an apparatus in an embodiment of the present invention, and FIG.
3 is a schematic diagram of a device according to another embodiment of the present invention, FIG. 4 is a characteristic diagram thereof, and FIG. 6 is a schematic diagram of a conventional device. 11...Reaction chamber, 12...Substrate, 14
...Exhaust pump, 16...Light transmission window,
17... Light source, 21... Heating body. Name of agent: Patent attorney Toshio Nakao and 1 other person 1st
Figure 2 Figure 3

Claims (1)

[Claims] 1. A film forming apparatus for forming a film by introducing a raw material gas into a reaction chamber having a vacuum evacuation function and a light transmission window, and irradiating light through the window, the film forming apparatus comprising a mechanism for heating the window.