JPH1145859A - Epitaxial growth equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an epitaxial growth equipment, capable of making the distribution of in-plane temperature of a substrate uniform by uniformly heating the substrate, accurately watching the substrate temperature, and maintaining the reproducibility of substrate temperature, in a substrate heating method and a substrate temperature watching method in a semiconductor thin-film growth process using an organic metal vapor growth method (MOVPE method). SOLUTION: In an epitaxial growth equipment, a reaction tube wherein a suscepter which mounts a semiconductor substrate is accommodated, a material gas supplying part is arranged in the upper part, and a quartz widow is arranged in the lower part, and a lamp-heating equipment adjacent to the quartz window are installed. A reaction-preventing means, which prevents a material gas from flowing into a space between the suscepter and the quartz window reacting with the quartz window, is installed. In this case, the reaction- preventing means is a carbon plate, which is arranged in contact with the quartz window and larger than the sectional area of a light source of a lamp-heating equipment, or a gas purge mechanism whose jet hole is arranged facing the quartz window and which is larger than the sectional area of the light source of the lamp heating equipment.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an epitaxial growth apparatus, and more particularly to an MOVPE method.
Method for improving a substrate heating method and a substrate temperature monitoring method in a semiconductor thin film growth process according to the present invention.

[0002] The MOVPE method is a crystal growth method in which a source gas is decomposed and reacted on a heated substrate to form a semiconductor thin film on the substrate. In order to grow a uniform semiconductor thin film with excellent reproducibility, the substrate must be grown. There is a need for an epitaxial growth apparatus capable of uniformly heating and accurately monitoring a substrate temperature.

[0003]

2. Description of the Related Art A conventional epitaxial growth apparatus will be described in detail with reference to FIG. FIG. 3 is a view showing a conventional epitaxial growth apparatus.

In a conventional epitaxial growth apparatus, a susceptor 2 for mounting a semiconductor substrate 11 to be processed is provided inside a reaction tube 1 as shown in FIG. A source gas supply unit 3 for supplying a source gas is provided at an upper portion of the reaction tube 1, and a quartz window 5 is provided at a lower portion of the reaction tube 1. A lamp heating device is provided adjacent to the quartz window 5. 6 are provided.

The susceptor 2 is supported by a susceptor support 4 and is rotated so as to make the temperature distribution in the plane of the semiconductor substrate 11 to be mounted and the supply of the source gas uniform. As the source gas supply unit 3, a honeycomb type injector is used so that the distribution of the film thickness formed on the semiconductor substrate 11 can be controlled.

[0006] As shown in the figure, the honeycomb type injector uses a plurality of mass flow controllers to divide the source gas, and as shown in the figure, the entire surface of the semiconductor substrate 11 by means of a 19 tapered supply pipe arranged in a honeycomb shape. This is to blow the raw material gas.

The lamp heating device 6 is composed of five linear lamps. The light passing through the opening of the shielding plate having an opening with a diameter of 100 mm passes through the quartz window 5 provided at the lower portion of the reaction tube 1. 1 is irradiated.

[0008] The raw material gas supplied from the raw material gas supply unit 3 into the reaction tube 1 is supplied to an exhaust port arranged around the reaction tube 1.
1a, the susceptor 2 and the quartz window 5 are diffused.
Into the space between them as shown by the arrows in the figure.

In order to grow an epitaxial growth film having a uniform in-plane film thickness distribution on the semiconductor substrate 11, it is necessary to improve the reproducibility of the substrate temperature. Therefore, the thermocouple 9 is provided below the susceptor 2. The temperature of the semiconductor substrate 11 is monitored.

A radiation thermometer 10 monitors the temperature of the semiconductor substrate 11 through a viewing window 1b provided in the reaction tube 1 separately from the thermocouple 9.

[0011]

In the conventional epitaxial growth apparatus described above, when the epitaxial growth is repeated a plurality of times, the epitaxial gas is supplied from the upper portion by the source gas supply unit and is not exhausted from the exhaust port of the reaction tube. The reaction of the raw material gas that has entered the space between the susceptor and the quartz window due to the diffusion with the heated quartz window causes clouding in the quartz window. There is a problem that the temperature distribution deteriorates and the reproducibility of the substrate temperature deteriorates.

Further, since the temperature gradient between the susceptor and the quartz window is very large, if the position of the thermocouple is shifted vertically during maintenance work, the reproducibility of the substrate temperature cannot be maintained, and the radiation thermometer cannot be used. Since the installation position is in the oblique direction, the reproducibility of the substrate temperature cannot be maintained in the oblique measurement, and if the observation window becomes cloudy, the reproducibility of the substrate temperature deteriorates.

In view of the above situation, the present invention is to uniformly heat a substrate, accurately monitor the substrate temperature, maintain the reproducibility of the substrate temperature, and make the distribution of the in-plane temperature of the substrate uniform. The purpose of the present invention is to provide a possible epitaxial growth apparatus.

[0014]

An epitaxial growth apparatus according to the present invention accommodates a susceptor on which a semiconductor substrate is mounted,
A source gas supply unit is provided at an upper part, and a reaction tube provided with a quartz window at a lower part, and an epitaxial growth apparatus provided with a lamp heating device adjacent to the quartz window. The apparatus is provided with a reaction preventing means for preventing the raw material gas flowing therebetween from reacting with the quartz window.

The reaction preventing means may be a carbon plate provided in contact with the quartz window and having a larger cross-sectional area than the light source of the lamp heating device, or an ejection hole may be provided facing the quartz window. The gas heating mechanism is configured to be larger than the cross-sectional area of the light source of the lamp heating device.

A thermocouple accommodating tube for accommodating a thermocouple is provided between the reaction preventing means and the susceptor, and a center of the susceptor and a center of a supply section of the source gas are provided. It is configured such that the radiation thermometer is provided on the line connecting.

That is, in the present invention, a susceptor is provided in a reaction tube, a semiconductor substrate is mounted on the susceptor, a source gas is supplied from a source gas supply unit provided at an upper portion of the reaction tube, and A semiconductor substrate to be processed is heated by a lamp heating device adjacent to the quartz window provided, and a reaction preventing means for preventing the source gas from reacting with the quartz window between the quartz window and the susceptor. Since the size of the reaction preventing means is made larger than the cross-sectional area of the light source of the lamp heating device, it is possible to prevent the raw material gas from reacting with the quartz window and causing clouding in the quartz window. As a result, the semiconductor substrate can be heated uniformly.

Further, since a thermocouple accommodating tube is provided between the reaction preventing means and the susceptor to accommodate the thermocouple, the position of the thermocouple does not change during maintenance work, so that the semiconductor substrate is not changed. It is possible to maintain the reproducibility of the temperature measurement. Further, since the radiation thermometer is provided on the line connecting the center of the susceptor and the center of the source gas supply section, the temperature of the semiconductor substrate can always be measured at the center.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below in detail with reference to FIGS. FIG. 1 is a view showing an epitaxial growth apparatus according to a first embodiment of the present invention, and FIG. 2 is a view showing an epitaxial growth apparatus according to a second embodiment of the present invention.

As shown in FIG. 1, the epitaxial growth apparatus of the first embodiment according to the present invention has a thickness of 10 mm in which a semiconductor substrate 11 to be processed is mounted in a reaction tube 1 similarly to a conventional epitaxial growth apparatus. A susceptor 2 made of carbon having a diameter of 80 mm is provided.

A source gas supply unit 3 for supplying a source gas is provided at an upper portion of the reaction tube 1, and a quartz window 5 having a diameter of 200 mm is provided at a lower portion of the reaction tube 1. An adjacent lamp heating device 6 is provided.

The susceptor 2 is supported by a susceptor support 4 and is rotated so as to make the temperature distribution in the plane of the semiconductor substrate 11 to be mounted and the supply of the source gas uniform. As the source gas supply unit 3, a honeycomb type injector is used so as to be able to control the distribution of the film thickness formed on the semiconductor substrate 11, similarly to the conventional epitaxial growth apparatus. Is 60 mm.

In the epitaxial growth apparatus of the first embodiment according to the present invention, a T-type joint is used at the center outlet of this honeycomb type injector to have a focal length of 250 mm.
semiconductor substrate 11 on which a radiation thermometer 10 mm is mounted on the susceptor 2
It is installed at a position 250mm vertically above and is purged with hydrogen so that the viewing window does not become cloudy.

The lamp heating device 6 is made up of five linear lamps as in the conventional epitaxial growth device, and the light passing through the opening of the shielding plate having an opening with a diameter of 100 mm is applied to the lower part of the reaction tube 1. The inside of the reaction tube 1 is irradiated through the quartz window 5 provided.

In this embodiment, a circular carbon plate 7 having a thickness of 3 mm and a diameter of 150 mm is provided in contact with the quartz window 5. Since the carbon plate 7 is unevenly heated by the lamp heating device 6 and the temperature distribution varies, the distribution of the thickness of the carbon plate 7 is reduced so that the temperature variation of the carbon plate 7 is reduced.
The intensity of the heat rays radiated to the surface is made uniform.

The distance between the carbon plate 7 and the susceptor 2 is
A thermocouple accommodating tube 9a made of a transparent quartz tube having a linear shape with an inner diameter of 2 mm was provided between the carbon plate 7 and the susceptor 2 and an R-type sheath thermocouple 9 was inserted therein.

In the epitaxial growth apparatus according to the first embodiment of the present invention, the carbon plate 7 is heated by the light emitted from the lamp heating device 6 and transmitted through the quartz window 5, and the heated carbon plate 7 is heated by a heat source. The semiconductor substrate 11 can be heated evenly because the susceptor 2 is rotated as the susceptor 2, and the thermocouple 9 inserted in the thermocouple housing tube 9 a provided at a distance of 10 mm between the susceptor 2 and the carbon plate 7. , The temperature of the thermocouple 9 does not change during maintenance, and the temperature of the center of the semiconductor substrate 11 mounted on the susceptor 2 is measured by the radiation thermometer 10. Therefore, the temperature distribution of the semiconductor substrate 11 can be controlled.

The raw material gas supplied from the raw material gas supply unit 3 into the reaction tube 1 is supplied to an exhaust port disposed around the reaction tube 1.
Since the carbon plate 7 evacuated and heated from 1a is provided in contact with the quartz window 5, the raw material gas that has entered the space between the susceptor 2 and the quartz window 5 by diffusion reacts with the quartz window 5. Thus, no fogging occurs on the surface of the quartz window 5.

As shown in FIG. 2, the epitaxial growth apparatus according to the second embodiment of the present invention is the same as the epitaxial growth apparatus according to the first embodiment. In the epitaxial growth apparatus according to the second embodiment of the present invention, a gas purge mechanism 8 made of transparent quartz and having a thickness of 5 mm and a diameter of 150 mm is provided at a distance of 5 mm from the quartz window 5. On the lower surface of the gas purge mechanism 8, 1,000 ejection holes 8a each having a diameter of 1 mm are provided, and purge gas is ejected from the ejection holes 8a. Thermocouple housing tube
9a was provided, and an R-shaped sheath thermocouple 9 was inserted therein.

In the epitaxial growth apparatus according to the second embodiment of the present invention, the susceptor 2 rotated by the light emitted from the lamp heating device 6 and transmitted through the quartz window 5 and the gas purge mechanism 8 is heated. The semiconductor substrate 11 can be heated evenly, and a thermocouple accommodating tube 9a made of a transparent quartz tube is provided between the susceptor 2 and the gas purge mechanism 8, and the temperature of the susceptor 2 is adjusted by the thermocouple 9 inserted therein. Since the measurement is performed, the position of the thermocouple 9 does not change during maintenance, and the temperature of the center of the semiconductor substrate 11 mounted on the susceptor 2 is measured by the radiation thermometer 10. Can be controlled.

The raw material gas supplied from the raw gas supply unit 3 into the reaction tube 1 is supplied to an exhaust port disposed around the reaction tube 1.
The raw material gas exhausted from 1a and entered into the space between the susceptor 2 and the quartz window 5 by diffusion is supplied to the gas purge mechanism 8
Is blown off by the purge gas blown out from the blowout hole 8a, so that the raw material gas does not react with the quartz window 5 to form cloud on the surface of the quartz window 5.

By performing monosilane (SiH ₄ ) doping whose doping concentration is sensitive to the growth temperature, the substrate heating and the reproducibility of the temperature monitor were checked for the first embodiment and the second embodiment.

Using a 2-inch indium phosphide (InP) substrate, monosilane (SiH ₄ ) doping was performed 100 times at a growth temperature of 650 ° C. to grow 1 μm each time. The distribution changed little after 100 growths. This indicates that reproducibility of substrate heating and its temperature monitor is high.

[0034]

As is apparent from the above description, according to the present invention, it is possible to prevent the source gas from reacting with the quartz window and forming cloudiness by a very simple structure change. Since the installation position of the semiconductor substrate is stabilized and the temperature of the semiconductor substrate is measured at the center, there is an advantage that the temperature of the semiconductor substrate can be measured stably and accurately. Can be provided.

[Brief description of the drawings]

FIG. 1 is a diagram showing an epitaxial growth apparatus according to a first embodiment of the present invention.

FIG. 2 is a view showing an epitaxial growth apparatus according to a second embodiment of the present invention;

FIG. 3 shows a conventional epitaxial growth apparatus.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Reaction tube 1a Exhaust port 1b Viewing window 2 Susceptor 3 Source gas supply part 4 Susceptor support part 5 Quartz window 6 Lamp heating device 7 Carbon plate 8 Gas purge mechanism 8a Spray hole 9 Thermocouple 9a Thermocouple housing tube 10 Radiation thermometer 11 Semiconductor substrate

Claims (5)

[Claims] 1. A reaction tube having a susceptor on which a semiconductor substrate is mounted, a source gas supply unit provided at an upper portion, and a quartz window provided at a lower portion, and a lamp heating device adjacent to the quartz window. An epitaxial growth apparatus comprising: a reaction preventing means for preventing the source gas flowing between the susceptor and the quartz window from reacting with the quartz window. 2. The epitaxial growth apparatus according to claim 1, wherein the reaction preventing means is a carbon plate provided in contact with the quartz window and having a larger cross-sectional area than a light source of the lamp heating device. 3. The epitaxial growth apparatus according to claim 1, wherein said reaction preventing means is a gas purge mechanism provided with a jet hole facing said quartz window and having a larger cross-sectional area than a light source of said lamp heating device. 4. The epitaxial growth apparatus according to claim 1, wherein a thermocouple accommodating tube for accommodating a thermocouple is provided between said reaction preventing means and said susceptor. 5. The epitaxial growth apparatus according to claim 1, wherein a radiation thermometer is provided on a line connecting the center of the susceptor and the center of the supply section of the source gas.