JP2003051454A - Vapor phase deposition system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a vapor phase deposition system which enables uniformizing of the surface temperature of a substrate to be processed, when forming a film and increasing a temperature by increasing the measurement accuracy of the surface temperature of a susceptor, thereby enabling further uniformizing of film-forming quality, such as film thickness. SOLUTION: The vapor phase deposition system comprises a quartz glass- made reaction vessel (1), the susceptor (7) disposed in the reaction vessel, an infrared lamp (5) which is disposed outside the reaction vessel and irradiates the susceptor and the substrate to be processed which is placed on the susceptor with infrared rays through the reaction container to heat the susceptor and the substrate, and a radiation thermometer (13), having a detection wavelength ranging between 1.8 and 2.1 μm which is disposed on the outside of the infrared lamp and measures a temperature of the susceptor through the reaction vessel.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vapor phase growth apparatus for performing lamp heating, and more particularly to improvement of a processing substrate surface temperature measuring apparatus.

[0002]

2. Description of the Related Art As a vapor phase growth apparatus used for growing a thin film on a silicon wafer, a high frequency heating method and a lamp heating method using an infrared lamp are known. A lamp heating type vapor phase growth apparatus is disclosed in, for example, Japanese Utility Model Laid-Open No. 2-52432 and has the following configuration. In this vapor phase growth apparatus, a plurality of flat plate-shaped susceptors are arranged in a truncated polygonal pyramid shape in a quartz glass reaction container, rotatably held, and a wafer is placed on the surface of the reaction container. The susceptor and the wafer mounted thereon are heated by irradiating infrared rays from an infrared lamp provided on the outside of the reactor through the reaction container. A reaction gas is introduced into this reaction container and reacted to grow a reaction product on the wafer. On the other hand, a radiation thermometer is arranged outside the infrared lamp, and infrared rays emitted from the surface of the susceptor are detected through the reaction container to measure the surface temperature of the susceptor and the wafer. Then, the heating by the infrared lamp is controlled based on the measured surface temperature. The radiation thermometer is calibrated with a thermocouple attached to the susceptor and rotation of the susceptor stopped.

In such a vapor phase growth apparatus, in order to make the film formation quality (especially the film thickness) of the thin film grown on the wafer more uniform, the surface temperature of the wafer during film formation and during temperature rise is uniform. Is desired.

Conventionally, in a lamp heating type vapor phase growth apparatus, similar to the one used in a high frequency heating type vapor phase growth apparatus, infrared rays having a wavelength of about 0.9 μm are detected, containing Si as a detection element material. A radiation thermometer was used.

However, when a radiation thermometer in which the detecting element material is Si is used in a lamp heating type vapor phase growth apparatus, the influence of the infrared rays emitted from the infrared lamp and the transmittance of the infrared rays passing through the reaction vessel made of quartz glass. Therefore, it has been found that the accuracy of measurement of the surface temperature by the radiation thermometer is lowered, which affects the control of the surface temperature of the wafer. Therefore, conventionally, it was not possible to improve the uniformity of the film-forming quality of the thin film grown on the wafer so much.

[0006]

SUMMARY OF THE INVENTION An object of the present invention is to improve the accuracy of surface temperature measurement, so that the surface temperature of a processed substrate can be made uniform during film formation and during temperature rise, and film formation quality can be made more uniform. It is to provide a vapor phase growth apparatus.

[0007]

A vapor phase growth apparatus according to the present invention comprises a reaction vessel made of quartz glass, a susceptor arranged in the reaction vessel, and a reaction vessel provided outside the reaction vessel. An infrared lamp that heats the susceptor and a processing substrate placed on the susceptor by irradiating infrared rays, and a detection wavelength that measures the temperature of the susceptor through the reaction container provided outside the infrared lamp and has a detection wavelength of 1. And a radiation thermometer having a diameter of 8 to 2.1 μm.

The radiation thermometer used in the present invention is
For example, the detection element material is preferably a PbSe-based semiconductor.

The radiation thermometer used in the vapor phase growth apparatus of the present invention detects infrared rays which are hardly affected by infrared rays having a wavelength emitted from an infrared lamp and which have a high transmittance through a reaction vessel made of quartz glass. Therefore, the measurement accuracy can be improved. Therefore, the surface temperature of the processed substrate during film formation and temperature rise can be made uniform, and the film formation quality represented by the film thickness can be made more uniform.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. 1 is a vertical cross-sectional view of a vapor phase growth apparatus according to an embodiment of the present invention, and FIG. 2 is a cross-sectional view taken along line II-II of FIG.

The reaction vessel 1 is a cylindrical quartz glass (SiO 2
₂ ), the exhaust port 2 is provided at the bottom portion thereof, and the top plate 3 is attached to the upper end of the exhaust port 2 so as to be openable and closable. The inside of the reaction container 1 is used as the reaction chamber 4.

A rotating shaft 6 is provided on the top plate 3, and a plurality of susceptors 7 are arranged at the lower end of the rotating shaft 6 so as to form a truncated polygonal pyramid shape and are rotatably supported. A wafer 8 as a processing substrate is placed on the surface of the susceptor 7.
Further, the top plate 3 is provided with a nozzle 9 for supplying a reaction gas and a purge gas.

As shown in FIGS. 1 and 2, the reaction container 1
A plurality of horizontally extending rod-shaped infrared lamps 5
Are arranged in an annular shape so as to surround the periphery of the reaction container 1, and the infrared lamps 5 having an annular shape are arranged in a plurality of rows along the longitudinal direction of the susceptor 7. As shown in FIG. 2, a reflection plate 11 is provided behind the infrared lamp 5 surrounding the reaction vessel 1 in an annular shape and between the infrared lamps 5. The infrared lamps 5 arranged at the same height along the longitudinal direction of the susceptor 7 are shown in FIG.
As shown by e, it is divided into a plurality of groups, and the output is controlled by the heating controller 12 independently of each other.

A screw shaft 14 is arranged vertically at a position outside the infrared lamp 5 so as to be substantially parallel to the surface of the susceptor 7, and a radiation thermometer 13 is engaged with the screw shaft 14. . The screw shaft 14 is rotated in the forward and reverse directions by the motor 16, and the radiation thermometer 13 is movable by the rotation of the screw shaft 14 over the entire length of the susceptor 7 in the longitudinal direction. A position detector 17 is connected to the motor 16. The position detector 17 detects the position of the radiation thermometer 13 in the susceptor longitudinal direction, and the output of the position detector 17 is given to the heating controller 12. As shown in FIG. 2, the radiation thermometer 1
The tip of 3 is located in the middle of the two rows of infrared lamps 5, and a window 15 is provided in the reflection plate 11 in the portion facing the radiation thermometer 13. The radiation thermometer 13 detects infrared rays emitted from the susceptor 7 through the window 15 and the reaction vessel 1 made of quartz glass to measure the surface temperature of the susceptor 7. The output of the radiation thermometer 13 is the heating controller 1
Given to 2.

In the present invention, a radiation thermometer having a detection wavelength of about 1.8 to 2.1 μm, for example, a detection element material containing PbSe is used. The reason for using such a radiation thermometer will be described. here,
FIG. 3 shows the relationship between the wavelength (λ) of infrared rays, the transmittance of infrared rays that pass through quartz glass, and the light amount of the infrared lamp. The following can be seen from FIG.

(1) The transmittance A of infrared rays transmitted through quartz glass (SiO ₂ ) has a minimum value at a wavelength of 2.7 μm, and shows a high value at a wavelength of 2.1 μm or less or in the vicinity of 3.4 μm. Therefore, it is preferable to select a radiation thermometer capable of detecting infrared rays having a wavelength showing a high transmittance.

(2) The light quantity B of the infrared lamp has a wavelength of 0.
It is maximum at 95 μm, and decreases at wavelengths around it. Therefore, it is preferable to reduce the influence of the infrared lamp by selecting a radiation thermometer that detects infrared rays having a wavelength in a region where the light amount B of the infrared lamp is small. When a conventional radiation thermometer that contains Si as a detection element material and detects infrared rays having a wavelength of about 0.9 μm was used, the influence of infrared rays emitted from an infrared lamp was large and the measurement accuracy was lowered.

(3) The amount of infrared light transmitted through quartz glass differs depending on the wavelength and thickness. It is also necessary to consider that the quartz parts have a large manufacturing error, and that the quartz parts are eroded by the chemical solution and are changed in size when they are washed for maintenance of the apparatus.
At a wavelength of 2.1 μm or less, there is no absorption of light by the quartz glass, which is irrelevant to the quartz glass, but since it is absorbed at wavelengths longer than that, it is greatly affected by the thickness of the quartz glass and at 3.4 μm. It absorbs 2% of infrared radiation with a thickness of 1 mm. Therefore, the measurement wavelength is preferably 2.1 μm or less.

Judging from the above (1) to (3), it is preferable to use a radiation thermometer having a detection wavelength in the vicinity of 1.8 to 2.1 μm, for example, one whose detection element material is PbSe. Further, the radiation thermometer in which the detection element material is PbSe can obtain a relatively large gain for infrared rays having a wavelength in the vicinity of 1.8 to 2.1 μm.

This vapor phase growth apparatus is operated as follows. While the susceptor 7 and the wafer 8 are radiantly heated from the surface by the infrared lamp 5, a reaction gas is supplied from the nozzle 9 into the reaction chamber 4 to cause reaction, and a reaction product is grown on the wafer 8. At this time, the motor 16 is operated at appropriate time intervals to move the radiation thermometer 13 along the vertical direction of the susceptor 7. The radiation thermometer 13 contains PbSe as a detection element material and has a detection wavelength of 1.8 to 2.1 μm.
Since it is in the vicinity, infrared rays transmitted through the quartz glass (SiO ₂ ) with high transmittance can be detected, and the influence of infrared rays emitted from the infrared lamp is small. Therefore, the surface temperature of the susceptor 7 can be measured with high detection accuracy.

Further, by giving the output of the radiation thermometer 13 and the output of the position detector 17 to the heating controller 12,
The average temperature is obtained for each of the control sections 5a to 5e of the infrared lamp 5. This temperature detection is continuously performed from the upper end to the lower end of the susceptor 7 by one radiation thermometer 13, so that the temperature distribution in the longitudinal direction of the susceptor 7 can be grasped accurately and accurately. The output of each infrared lamp 5 is feedback-controlled based on the value of these average temperatures, and the susceptor 7
To make the temperature distribution in the longitudinal direction uniform. Control division 5a-5
The value e is determined according to the temperature distribution characteristic along the longitudinal direction of the susceptor 7, and the temperature distribution can be made uniform more accurately in a smaller number of sections. In addition,
The temperature distribution in the circumferential direction of the susceptor 7 is made uniform by the rotation of the susceptor 7.

Since an appropriate radiation thermometer is used in such a vapor phase growth apparatus, the influence of the infrared rays emitted from the infrared lamp is small, and the infrared rays emitted from the susceptor surface can be measured with high accuracy. Therefore, the surface temperature of the wafer can be made uniform during the film formation and the temperature rise by the feedback control, and the film formation quality of the thin film grown on the wafer can be made uniform.

In the above-described embodiment, an example of a vapor phase growth apparatus using a plurality of flat plate-shaped susceptors 7 each having a truncated polygonal pyramid is shown. However, a disk-shaped susceptor which is arranged substantially horizontally and rotates, The present invention can be applied to various types of vapor phase growth apparatus using a non-rotating type square plate susceptor and the like.

[0024]

As described in detail above, according to the vapor phase growth apparatus of the present invention, the measurement accuracy of the surface temperature of the susceptor can be improved, and the surface temperature of the processed substrate can be made uniform during film formation and temperature rise. The film formation quality (especially the film thickness) on the processed substrate can be made uniform.

[Brief description of drawings]

FIG. 1 is a vertical sectional view of a vapor phase growth apparatus according to an embodiment of the present invention.

FIG. 2 is a sectional view taken along line II-II in FIG.

FIG. 3 is a diagram showing a relationship between an infrared wavelength (λ), a transmittance A through quartz glass, and a light amount B of an infrared lamp.

[Explanation of symbols]

1 ... Reaction vessel 2 ... Exhaust port 3 ... Top plate 4 ... Reaction chamber 5 ... Infrared lamp 6 ... Rotary axis 7 ... Susceptor 8 ... Wafer 9 ... Nozzle 11 ... Reflector 12 ... Heating control unit 13 ... Radiation thermometer 14 ... screw shaft 15 ... window 16 ... Motor 17 ... Position detection unit

Claims (2)

[Claims] 1. A reaction vessel made of quartz glass, a susceptor arranged in the reaction vessel, and an infrared ray radiated through the reaction vessel provided outside the reaction vessel to mount the susceptor and the susceptor thereon. And an infrared thermometer having a detection wavelength of 1.8 to 2.1 μm, which is provided outside the infrared lamp and measures the temperature of the susceptor through the reaction container. A vapor phase growth apparatus characterized by the above. 2. The detection element material of the radiation thermometer is PbS
The vapor phase growth apparatus according to claim 1, wherein the vapor phase growth apparatus is e.