JPS63314828A - Photo-cvd equipment - Google Patents

Abstract

PURPOSE:To make it unnecessary to remove a window for cleaning, by installing a reaction chamber and a cleaning chamber on both sides of a lamp chamber, and rotating the contaminated window to the cleaning chamber side to clean it, when a substrate in the reaction chamber is irradiated with ultraviolet rays through the window arranged in the lamp chamber to form a film and the window is contaminated. CONSTITUTION:A reaction chamber 1 accommodating a semiconductor substrate 2 is provided with a material gas feeding inlet 3, a discharging vent 4 and an inlet 3B to feed gas which restrain the film from attaching to a window and does not contribute to reaction. On the opposite side of the reaction chamber 1 with respect to a lamp chamber 12, a cleaning equipment 8 provided with a gas feeding inlet 9A for plasma etching and a discharging vent 9B is installed, and therein a discharging electrode 10 as included. In the lamp chamber 12 situated between the two chambers, a plurality of ultra-violet ray sources 6 provided with a reflector 7 behind them are arranged. A plurality of windows 5A, 5B situated between the ultra-violet ray sources 6 and the substrates 2 are constituted so as to be able to rotate toward the reaction chamber 1 side and the cleaning chamber 8 side by a driving equipment 13. When the window in use is contaminated, which is monitored by using a film thickness meter 11, the window is transferred to the chamber 8 side to be cleaned.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to the field of thin film formation, particularly to a film formation apparatus using a photo-excited gas phase reaction used in the production of semiconductor devices and the like.

Conventional technology The so-called photo-CVD method, which utilizes optical excitation, particularly the decomposition of raw material gas by ultraviolet light, has the following characteristics when compared to plasma CVD methods: (7) It is a low-temperature process.

(a) There shall be no damage to the base or substrate due to ion bombardment, etc.

(1) Selective film formation is possible using a laser beam, etc.

It is expected that it will have superiority in these respects.

However, there are still problems to be solved in order to put the photoCVD method into practical use, and among them, film adhesion to the light introduction window is a major problem. Various proposals have been made to avoid this, such as flowing a gas that does not participate in the reaction along the window, or applying a special chemical to the window.

Problems to be Solved by the Invention However, even with these methods, it is not possible to completely prevent the film from adhering to the window. The ultraviolet light used in the photoCVD method is in a region called vacuum ultraviolet and has a short wavelength of 200 nm.
In some cases, it is less than m. Ordinary glass has low transmittance for light with such short wavelengths, and the efficiency of the photoexcited decomposition reaction necessary for film formation is extremely low. Therefore, windows made of materials that transmit relatively well short wavelength light, such as synthetic quartz, are used. are doing. Even in this case, as the film adheres to the window, the transmittance of ultraviolet light decreases, and film formation gradually becomes difficult.

Therefore, after a certain period of use, the windows must be cleaned by some method. As a cleaning method, there is a method of removing the window from the equipment and dissolving the attached film, but this usually requires the use of powerful chemicals, and there are many handling problems such as subsequent washing and drying. .

Furthermore, when forming a film over a large area, there is a limit to the size of a single window, and handling a large window is difficult in practice.

In order to solve the above problems, it is an object of the present invention to provide a photo-CVD apparatus that facilitates cleaning of a light introduction window, prevents a decrease in light transmittance, and prevents a decrease in film-forming efficiency. It is.

Means for Solving the Problems In order to achieve the above object, the optical CVD apparatus of the present invention has the following features:
A reaction method comprising a plurality of continuously arranged light introduction windows, individually independent reaction chambers, a cleaning chamber and a light introduction window support for transporting the light introduction windows between the reaction chamber and the cleaning chamber, The feature is that the window used in the cleaning room can be replaced with a window from which deposits have been removed by plasma etching or the like in the cleaning room.

Function According to the above configuration, the light introduction window located in the reaction chamber during the reaction can be transported to the cleaning chamber by the support, and cleaning can be performed without removing it from the apparatus. It becomes possible to perform film formation in the chamber and removal of the deposited film in the cleaning chamber in an appropriate cycle, and as a result, effects such as a decrease in film formation efficiency due to a decrease in light transmittance can be kept to a minimum. .

Embodiments Hereinafter, embodiments of the present invention will be described based on the drawings.

FIG. 1 is a sectional view of a photo-CVD apparatus according to an embodiment of the present invention. In the figure, a substrate 2 is mounted in a reaction chamber 1, and a reaction gas is introduced through an inlet 3A and exhausted through an exhaust port 4. In addition, in order to suppress film adhesion to the window 5A (sB) as much as possible,
A gas that does not participate in the reaction is introduced through the inlet 3B and exhausted through the exhaust port 4. A plurality of linear low-pressure mercury lamps are used as the ultraviolet light source 6, and a reflecting plate 7 is provided to increase the irradiation intensity and improve uniformity. A gas for plasma etching is introduced into the cleaning chamber 8 through an inlet 9A and an exhaust port 9B.
It has become more exhausting, and the discharge electrode 1
0 is set.

Cleaning of the ultraviolet light introducing windows sA and sB is performed in the following rotation. Assume now that the window 5A is on the reaction chamber 1 side, and the window 6B is on the cleaning chamber 8 side. As the film is formed on the substrate 2 in the reaction chamber 1, a certain amount of film also adheres to the window 5A, and when the amount increases, the ultraviolet light transmittance decreases, thereby affecting the film formation. Therefore, film thickness meter 1
1 monitors the amount of film adhered, and when a predetermined amount is reached, the reaction chamber 1, cleaning chamber 8, and lamp chamber 12 are brought to atmospheric pressure, and the drive device 13 moves the window with the film adhered to the cleaning chamber 8 side, and , the windows 5B that have been cleaned are moved to the reaction chamber 1 side. In this way, in the reaction chamber 1, the cleaned window 6B is used to form a film, and in the cleaning chamber 8, the window 5A is used to form a film.
The film attached to the surface is removed by plasma etching. As mentioned above, window sA.

By moving 5B, one side is used for film formation.
- while the other can be cleaned.

FIG. 2 shows the window and its supporting structure. The window support has a structure in which two parts (as shown in FIG. 2(a)) are connected as one unit. A cross-sectional view taken along line B1-B2 is shown in FIG. 2(b). The window 21 is attached to a support 22, which is connected by a link 23. This support body 22 comes into contact with the chamber-side frame 24 via the O-ring 26, thereby maintaining the vacuum state within the chamber.

According to the above embodiment, by providing the two ultraviolet light introduction windows movably between the reaction chamber and the cleaning chamber, the window can be cleaned without removing the window from the apparatus, thereby increasing the operating efficiency of the apparatus. Moreover, it becomes possible to efficiently prevent a decrease in ultraviolet light transmittance.

FIG. 3 is a sectional view showing the structure of another embodiment of the optical CVD apparatus suitable for mass production according to the present invention. In the figure, 31A, 3
1B is a reaction chamber, 32 is a lamp chamber, 33A and 33B are cleaning chambers, and 34 is a window and its support.

Similar to the configuration in the first embodiment described above, window rotation allows the window 3 to be opened in the cleaning chambers 33A and 33B during film formation in the reaction chambers 31A and 31B.
4 cleaning can be performed.

If such a configuration is used, the light C having the configuration shown in FIG.
The functions of two VD devices can be provided in a much smaller space, and since the lamp chamber is shared, film deposition can be performed without any time loss.

Effects of the Invention According to the present invention, a reaction chamber, a cleaning chamber, and a plurality of light introduction windows are provided, and the light introduction window is provided so that it can be transported between the reaction chamber and the cleaning chamber, thereby removing the film attached to the window. Perform IJ-ning, which requires removing the window for removal.
Window gluing can be easily carried out before the film formation rate is significantly reduced due to a decrease in ultraviolet light transmittance due to film adhesion, leading to improved operational efficiency. Furthermore, if the configuration of the present invention is used, it is easy to increase the size of the device, and it is also effective for use in mass production.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing the configuration of an optical CVD apparatus according to an embodiment of the present invention, FIG. is the same (
FIG. 3 is a cross-sectional view taken along line B1-B2 in a), and a cross-sectional view showing the configuration of a mass-produced optical CVD apparatus that shares a lamp chamber according to another embodiment of the present invention. 1...Reaction chamber, 5...Window, 6...
...Ultraviolet light source, 8...Cleaning room, 13.
...1 drive device, 22 ... window support, 2
4...Chamber frame, 31A. 31B...Reaction chamber, 32...Lamp chamber,
33A. 33B...Cleaning room. Name of agent: Patent attorney Toshio Nakao and 1 other person1-
11-tan E:, room 7- 斥圜くま8-1-kwa; ngsen 12-1-ra, wa, room

Claims (2)

[Claims] (1) A photo-CVD device that forms a film on a substrate from a gas phase by photolyzing a source gas, and has separate reaction chambers and cleaning chambers, and light from a lamp chamber is introduced into the reaction chamber. It includes a plurality of light introduction windows and a light introduction window carrier for transporting the plurality of light introduction windows between the reaction chamber and the cleaning chamber, and the light introduction window used in the reaction chamber and the light introduction window used in the cleaning chamber are attached. An optical CVD apparatus characterized in that the kimono is replaced with a light introducing window from which the kimono has been removed. (2) The optical CVD apparatus according to claim 1, wherein light is irradiated from one shared lamp chamber to a plurality of light introduction windows arranged on the reaction chamber side.