JPS63289927A - Photochemical vapor phase deposition device - Google Patents

Abstract

PURPOSE:To make it possible to reliably prevent reaction species and reaction products from adhering to a light-transmitting window by a method wherein the window is interconnected to the side of the interior of a reaction container from the side of a light source unit, gas conducting paths for conducting inactive gas are provided in large numbers and the sites, which are positioned on at least the side of the interior of the reaction container, of the gas conducting paths are slanted to a light irradiation direction. CONSTITUTION:A reaction container 1 for vapor phase chemical reading utilizing the energy of light in its interior; a susceptor 14 which is installed in the container 1 and whereon substrates 13 are mounted; a light source unit 7 which is installed in the container 1 and irradiates light on the substrates 13; a light-transmitting window 6 arranged between the substrates 13 and the unit 7; reaction gas supply pipes 8 and 9, through which gas to be excited and decomposed by light is introduced in the container 1 and is blown off to a region being irradiated with the light; and so on; are provided. In such a photochemical vapor phase deposition device, with the window 6 interconnected to the side of the interior of the reaction chamber from the side of the unit 7, numerous gas conducting paths 6A for conducting inactive gas are provided and the sites, which are positioned on at least the side of the interior of the reaction chamber, of the paths 6A are slanted to the light irradiation direction.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a photochemical vapor deposition apparatus, and particularly to a so-called self-contained photochemical vapor deposition apparatus in which a light source device such as an ultraviolet lamp is installed in a reaction chamber. , prevents fogging of light-transmitting windows,
The present invention relates to a photochemical vapor deposition apparatus suitable for improving the rate of film production through photochemical vapor phase reactions.

[Conventional technology]

Conventionally, there are basically two types of photochemical vapor deposition apparatuses: one type in which an ultraviolet lamp is installed outside a reaction vessel, and the other type in which an ultraviolet lamp is installed inside the reaction vessel.

In the case of a photochemical vapor deposition apparatus of the type in which an ultraviolet lamp is installed outside the reaction vessel, a light transmission window through which the ultraviolet lamp is transmitted constitutes a part of the reaction vessel. In a photochemical vapor phase deposition apparatus, in order to evacuate the interior of the reaction vessel during the operation of a photochemical vapor phase reaction, the light transmission window that constitutes a part of the reaction vessel must have a pressure-resistant structure that accompanies the evacuation.

Furthermore, in order to deposit films on a large number of substrates, it is necessary to increase the area of the light transmission window. However, in order to make the light transmission window have a pressure-resistant structure and to increase the area, the thickness of the light transmission window must be increased for strength reasons. When the thickness of the light-transmitting window is increased to j\, the transmittance of ultraviolet rays decreases, and the deposition rate of the film decreases.

Therefore, as a means to eliminate the above-mentioned disadvantages, there is a so-called built-in photochemical vapor deposition apparatus in which an ultraviolet lamp is installed in a reaction vessel. In this photochemical vapor deposition apparatus, the wall surface of the reaction container may have a pressure-resistant structure, and therefore the light-transmitting window can be made thinner, and a decrease in ultraviolet transmittance due to the light-transmitting window can be prevented.

However, when a film is deposited on a substrate by a photochemical vapor phase reaction, reactive species and reaction products adhere to the light-transmitting window, causing clouding of the light-transmitting window. As a result, a phenomenon occurs in which the film deposition rate decreases. As a photochemical vapor deposition apparatus having a light-transmitting window that prevents fogging of the light-transmitting window,
A photochemical vapor deposition apparatus described in Japanese Patent No. 1778 has been proposed. In this photochemical vapor deposition apparatus, a plate (light transmission window) having many pores parallel to the light beam direction is inserted between the reaction irradiation light source (ultraviolet lamp) of the photochemical vapor deposition apparatus and the photochemical reaction vessel. However, it is described that a diluent gas such as helium, for example, is caused to flow on the side of the reaction irradiation light source, and the diluent gas is blown out from the pores into a low-pressure photochemical reaction vessel.

[Problem that the invention seeks to solve]

In the conventional photochemical vapor deposition apparatus described above, the diluent gas has the effect of suppressing the attachment of reactive species and reaction products to the light transmission window. However, since the pores formed in the light transmission window are provided parallel to the light beam direction, the diluent gas is blown out almost perpendicularly to the surface of the light transmission window, and the adjacent pore exits on the surface of the light transmission window There is a problem in that many regions are formed in between where the diluent gas does not flow, and reactive species and reaction products adhere through these regions, causing clouding of the light transmission window.

The purpose of the present invention is to solve the problems of the prior art described above,
In a built-in photochemical vapor deposition device that allows thinning of the light-transmitting window, it is possible to reliably prevent reactive species and reaction products from adhering to the light-transmitting window and improve the deposition rate of the film on the substrate. An object of the present invention is to provide a photochemical vapor deposition apparatus.

[Means for solving problems]

In order to achieve the above object, the present invention provides a light transmission window with a large number of gas passages for communicating from the light source device side area to the inside of the reaction vessel and for conducting an inert gas.
At least the portions of these gas paths located on the inside of the reaction vessel are inclined with respect to the light irradiation direction.

[Effect]

Inert gas is supplied from the light source device side through a number of gas passages formed inside the light transmission window.

This inert gas forms a laminar gas flow along the surface of the light transmitting window through the gas guide path inclined with respect to the light irradiation direction. This layered gas flow reliably suppresses adhesion of reactive species and reaction products present inside the reaction vessel to the surface of the light transmission window.

As a result, fogging of the light transmission window is suppressed, and the film deposition rate can be improved.

[Embodiments of the invention]

Hereinafter, embodiments of the present invention will be described based on concave surfaces.

FIG. 1 is a schematic configuration diagram showing the overall configuration of the present invention.

In FIG. 1, a preparatory chamber 3 is provided, which is partitioned via a gate valve 2 and a reaction vessel 1 in which a gas phase chemical reaction is carried out using light energy. An infrared lamp 4 is installed on the ceiling side inside the reaction vessel 1, and the area where the infrared lamp 4 is installed is separated from the gas phase reaction area by a transmission plate 5 in which a large number of pores are formed. Further, an ultraviolet lamp 7 is installed on the bottom side of the reaction vessel 1, and the area where the ultraviolet lamp 7 is installed is separated from the gas phase reaction area by a light transmission window 6.

Furthermore, a reaction gas supply pipe 8 in which a valve 8A, a mass flow controller 8B, and a valve 8C are interposed, and a reaction gas supply pipe 9 in which a valve 9A, a mass flow controller 9B, and a valve 9C are interposed are provided in the reaction vessel l. ing.

Inert gas supply pipe with valve IOA is valve IOB
an inert gas supply pipe 10 in which a valve IIA is interposed and communicated with the preliminary chamber 3; and an inert gas supply pipe II in which a valve IIA is interposed and communicated with the installation area of the infrared lamp 4.
, the bulb 12A is interposed, and the ultraviolet lamp 7
and an inert gas supply pipe 12 communicating with the area.

A susceptor 14 that supports a substrate 13 on which a film produced by a gas phase chemical reaction is deposited is disposed approximately at the center of the reaction vessel 1 . The preliminary chamber 3 is provided with a substrate transfer device 16 operated by a drive device 15, and the operation of the substrate transfer device 16 causes the susceptor 14 to open and close as the gate valve 2 opens and closes.
The substrate 13 supported by the substrate 13 can be moved to the reaction vessel 1 or the preliminary chamber 2 as appropriate.

Further, an exhaust pipe 17 for discharging unreacted gas and reaction products in the reaction vessel 1 and an exhaust pipe 18 for discharging the interior of the preliminary chamber 3 are provided, and the pressure inside the reaction vessel 1 is measured. A pressure gauge 19 and a pressure gauge 20 for measuring the pressure inside the preliminary chamber 3 are installed.

The light transmission window 6 in FIG. 1 is provided with a large number of slit-shaped gas conduction paths 6A, as shown in FIGS. It is sloping. And these gas passages 6A
is inclined towards the downstream side of the gas flow introduced from the reaction gas supply pipe 8.9 in FIG.

4 and 5 show another embodiment of the light transmitting window, in which the light transmitting window 21 is provided with a large number of pores 21A at regular intervals in a staggered manner over the entire plane thereof. As shown in FIG. 5, the reaction gas supply pipe 8.9 is also inclined at an angle of approximately 45 degrees toward the downstream side of the gas flow introduced from the reaction gas supply pipe 8.9.

Next, the functions and effects of the photochemical vapor deposition apparatus configured as described above will be explained.

First, the inside of the reaction vessel 1 is evacuated through the exhaust pipe 17, and the inside of the preliminary chamber 3 is evacuated through the exhaust pipe 18. In this state, the gate valve 2 is opened, and the substrate 13 supported by the susceptor 14 is placed in the illustrated position in the reaction vessel 1 by the substrate transfer device 16 operated by the drive device 15. After this, the gate valve 2 is closed.

Next, the infrared lamp 4 is energized via a power source (not shown), and the susceptor 4 and the substrate 13 are heated to a predetermined temperature by the infrared rays transmitted from the infrared lamp 4 through the transmission plate 5. Further, the ultraviolet lamp 7 is energized via a power supply (not shown), and the light transmitting window 6 is supplied with electricity from the ultraviolet lamp 7.
The substrate 13 is irradiated with ultraviolet light having a wavelength of, for example, 254 nm or 185 nm.

In this state, valve 8A, mass flow controller 8B
A reactive gas such as 5iHa is supplied from the reactive gas supply pipe 8 via the valve 8C, and a reactive gas such as 5iHa is supplied to the reactive gas supply pipe 9 via the valve 9A, the mass flow controller 9B, and the valve 9C.
From there, a reactive gas such as N Hz is introduced into the region formed between the light-transmitting window 6 and the gas 13 . Here, the reaction gas is converted into Si by a gas phase chemical reaction using the energy of ultraviolet light.
Reaction products such as 3N4 are deposited on the substrate 13.

When depositing a film on the substrate 13 by such a gas phase chemical reaction, the bulb IOA is placed in the area where the infrared lamp 4 is installed.
An inert gas such as helium is supplied from an inert gas supply pipe 1) via a mass flow controller IOB and a valve IIA. At the same time, a bulb 10A is installed in the installation area of the ultraviolet lamp 7.

An inert gas such as helium is supplied from an inert gas supply pipe 12 via a mass flow controller IOB and a valve 12A. The inert gas supplied to the installation area of the infrared lamp 4 is ejected from the pores of the transmission plate 5 due to the pressure difference between the installation area of the infrared lamp 4 and the inside of the container in which the substrate 13 is placed. As a result, it is possible to prevent reactive species and reaction products from adhering to the surface of the transmission plate 5. For this reason, the susceptor 1
4 and the substrate 13 from decreasing in infrared intensity;
The heating temperature of the substrate 13 can also be easily adjusted.

The inert gas supplied to the installation area of the ultraviolet lamp 7 is
Due to the pressure difference between the installation area of the ultraviolet lamp 7 and the inside of the container in which the substrate 13 is placed, gas is ejected from the gas introduction paths 6A and 21A formed in the light transmission window 6.21. At this time, since the gas guide paths 6A and 21A are each inclined, the inert gas ejected into the container flows along the surface of the light transmission window 6.21 as shown in FIGS. 3 and 5. , a laminar gas flow of inert gas is likely to be formed on the surface of the light transmission window 6.21, and a so-called dead zone formation area is less likely to occur.Furthermore, the gas conduction paths 6A and 21A are inclined toward the downstream side of the reactant gas flow. Therefore, the gas conduction paths 6A, 21
The inert gas ejected from A reliably forms a laminar gas flow without being hindered by the reaction gas flow. Therefore, adhesion of reactive species and reaction products to the light transmission window 6.21 is reliably prevented.

Further, in the photochemical vapor deposition apparatus described above, the inside of the container is evacuated, and a pressure-resistant structure for this purpose is formed on the wall surface of the reaction container 1. Therefore, the transmitting plate 5 and the light transmitting window 6 do not need to have a pressure-resistant structure that is required when the inside of the container is evacuated, so that both can be made thinner.

When producing a thin film using light energy, resonance lines of 254 nm and 185 nm are usually generated by a low-pressure mercury lamp.
It uses ultraviolet light with a wavelength of

Synthetic quartz glass is commonly used as a material effective for transmitting such ultraviolet rays. FIG. 7 shows the relationship between the wavelength of light and the transmittance of the light in synthetic quartz glass for each thickness of the synthetic quartz glass. As is clear from FIG. 7, the transmission rate of light with a wavelength around 185 nm, which is effective when producing a thin film using optical energy, decreases as the thickness of the synthetic quartz glass increases.

On the other hand, recent conference presentations have shown that the film deposited by irradiating a reactive gas with ultraviolet rays is related to the ultraviolet intensity (usually expressed in mW/cd) [for example, Takahashi et al. : Irradiation wavelength dependence of photoCVD process of SiO1 film: 46th Japan Society of Applied Physics (1985 Fall 2P-
W-5)). Therefore, making the light transmitting window thicker will slow down the film deposition and result in a decrease in throughput. Film deposition rate can be improved.

Furthermore, since the transmission plate 5 is also made thinner, the transmission of infrared rays is further improved, and the substrate 13 can be heated more efficiently due to the effect of preventing adhesion of the transmission plate 5 by the inert gas.

The gas conduction path formed in the above-mentioned light transmission window 6.21 is
The angle does not necessarily have to be 45 degrees, but can be any angle necessary to form a laminar inert gas flow on the surface of the light-transmitting window 6.21. Although the angle may be large, it should be selected appropriately in relation to the strength of the light transmission window 6.21.

Further, the gas conduction path does not have to be formed to be linearly inclined in the cross section of the light transmission window, but may be a slit or a pore of any shape; The part located at must be inclined.

FIG. 6 is a detailed view of main parts showing another embodiment of the present invention.

In FIG. 6, a current plate 22 is disposed near the gas outlet of the reaction gas supply pipe 9.8.

In this embodiment, the gas ejected from the reaction gas supply pipe 9.8 is converted into an N flow by the rectifying plate 22, preventing diffusion toward the light transmitting window 6, and at the same time inactivating the gas along the surface of the light transmitting window 6. Since a laminar gas flow is formed by the gas, adhesion of reactive species and reaction products to the light transmission window 6 can be more reliably prevented.

〔Effect of the invention〕

As described above, according to the present invention, the inert gas ejected from the light-transmitting window into the reaction vessel forms a layered gas flow along the surface of the light-transmitting window. It is possible to reliably prevent objects from adhering to the surface of the light transmitting window. Therefore, it is possible to avoid fogging of the light transmission window and improve the film deposition rate.

[Brief explanation of drawings]

FIG. 1 is a schematic configuration diagram showing the overall configuration of the photochemical vapor deposition apparatus of the present invention, FIG. 2 is a plan view of the optical i3 pass window in FIG. 1, and FIG. 3 is an A-A in FIG. 2. 4 is a plan view showing another example of the light transmitting window in FIG. 1, FIG. 5 is a sectional view taken along the line B-B in FIG. 4, and FIG. FIG. 7 is a detailed view of the main part showing another embodiment of the vapor deposition apparatus, and is a graph showing the relationship between wavelength and transmittance depending on the thickness of quartz glass. 1...Reaction vessel, 2...Gate valve, 3
...Preliminary room, 4...Infrared lamp, 5
...Transmission plate, 6.21...Light transmission window,
6A, 21A...Gas conduction path, 7...
Ultraviolet lamp, 8.9... Reaction gas supply pipe, 1
0.1). 12... Inert gas supply pipe, 13.
...Substrate, 14...Susceptor, 15...
...Drive device, 16...Substrate transport device, 1
7.18... Exhaust pipe, 19.20...
Pressure gauge, 22... Rectifier plate. Agent Patent Attorney Masaru Nishimoto - Figure 2 Figure 3 Figure 4 Figure 5 2″IA

Claims (5)

[Claims] (1) A reaction vessel in which a gas phase chemical reaction is performed using light energy; a susceptor installed in the reaction vessel and to which a substrate is attached; and a susceptor installed in the reaction vessel and attached to the substrate. A light source device that irradiates light, a light transmitting window arranged between the substrate and the light source device, and a gas that is excited and decomposed by the light is introduced into the reaction container and the area that is irradiated with light is exposed to the light. In a photochemical vapor deposition apparatus comprising a reaction gas supply pipe for blowing out and a discharge pipe for discharging unreacted gas and reaction products in the reaction container, the light transmission window extends from the light source device side region to the reaction chamber. It has a large number of gas conduction passages that communicate with the interior and conduct inert gas, and most of these gas passages have at least a portion located on the inside of the reaction chamber that is inclined with respect to the direction of light irradiation. A photochemical vapor deposition device characterized by: (2) The photochemical vapor deposition apparatus according to claim (1), wherein each of the gas conduction paths is a slit-like hole inclined with respect to the light irradiation direction. (3) Each of the gas conduction paths is a pore inclined with respect to the light irradiation direction.
1) The photochemical vapor deposition apparatus described in item 1). (4) Claim (1) characterized in that the gas conduction path is inclined in the flow direction in the reaction vessel of the reaction gas introduced into the reaction chamber from the reaction gas supply pipe. Photochemical vapor deposition apparatus as described. (5) A photochemical vapor deposition apparatus according to claim (1), characterized in that a rectifying plate is disposed in an area from the outlet of the reaction gas supply pipe to a substrate placement area in the reaction chamber. .