JPH06244114A - Vapor growth equipment - Google Patents

Abstract

PURPOSE:To provide a vapor growth equipment which is capable of vapor growth of a high quality thin film and excellent in safety. CONSTITUTION:In a reaction furnace, a susceptor 3 retained by the one end of a rotary retainer 2 is arranged, a substrate 4 is mounted on the susceptor 3, and a heater 9 as a heating means for heating the substrate 4 via the susceptor 3 is fixed under the susceptor 3. In order to keep the substrate 4 at a constant temperature, a recessed part 11 for measuring the temperature is formed at the center of the underside of the susceptor 3, and a thermocouple 12 as a means for temperature measurement is inserted in the recessed part 11. As to the thermocouple 12, a protective cover 19 is formed on the outer periphery from the tip part to the vicinity of the heater 9. The thermocouple 12 is connected with a temperature controller 13, which controls the temperature of the heater 9 by the output.

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 used for manufacturing, for example, a compound semiconductor having a hetero structure.

[0002]

2. Description of the Related Art FIG. 8 is a schematic diagram showing the structure of a conventional vapor phase growth apparatus.

A susceptor 3 supported at one end of a rotary support 2 is arranged in a reaction furnace 1, and a substrate 4 is provided on the susceptor 3.
Is placed. The other end of the rotary support 2 is connected to a motor 8 via pulleys 5, 6 and a belt 7. A heater 9 for heating the substrate 4 via the susceptor 3 is attached to the lower portion of the susceptor 3, and a reflector 10 for reflecting the heat of the heater 9 is attached below the heater 9. Further, in order to maintain the substrate 4 at a constant temperature, in order to measure the temperature of the susceptor 3, a recess 11 is provided in the lower center part thereof, and passes from the outside of the reaction furnace 1 through the central parts of the heater 9 and the reflection plate 10, The thermocouple 12 is placed in the recess 11.
The tip of is inserted. The thermocouple 12 is connected to a temperature controller 13, and the temperature of the heater 9 is adjusted by the temperature controller 13 based on the output thereof. A method of vapor-depositing a semiconductor thin film on the substrate 4 by the vapor-phase growth apparatus having the above configuration will be outlined.

The substrate 4 is placed on the susceptor 3 and the reaction furnace 1
After substituting the internal air with an inert gas, the motor 8 is driven to rotate the rotary support 2 and appropriately rotate the susceptor 3 on which the substrate 4 is placed. Next, a predetermined gas (for example, H
₂ , AsH ₃ etc.) to keep the pressure in the reaction furnace 1 constant, and the heater electrode 14 from the temperature controller 13 heats the heater 9 to raise the temperature of the susceptor 3. At that time, after raising the temperature of the susceptor 3 to a temperature preset by the temperature controller 13, the temperature of the susceptor 3 is appropriately measured by the thermocouple 12, and the temperature controller 13 is used so that the temperature becomes constant. The temperature of the heater 9 is controlled. After the temperature of the susceptor 3 reaches a predetermined temperature, a growth gas (for example, TMA, TMG, etc.) is introduced into the reaction furnace 1 through the gas introduction port 15, and the growth gas is introduced onto the substrate 4.
Vapor growth of a semiconductor thin film.

The problem here is that the temperature of the substrate 4 fluctuates during vapor phase growth. The temperature fluctuation of the substrate 4 during the vapor phase growth becomes a problem, for example, when the manufactured semiconductor is used as a laser diode or the like. In general, the oscillation wavelength of the laser diode has a relationship that the shorter the temperature of the substrate 4 during vapor phase growth is, the longer the temperature is low. That is, if the temperature of the substrate 4 fluctuates during vapor phase growth, the characteristics of the laser diode will change. Therefore, it is necessary to keep the temperature of the substrate 4 constant at all times. Therefore, as described above, the thermocouple 1
2 measures the temperature of the susceptor 3, and the temperature controller 13 controls the temperature of the heater 9.
The temperature of the substrate 4 fluctuates due to the following causes.

FIG. 9 is a partially enlarged view showing an outline of a temperature measuring portion of a susceptor in a conventional vapor phase growth apparatus. As described above, the tip of the thermocouple 12 is inserted in the recess 11 provided in the lower center of the susceptor 3. Further, the thermocouple 12 passes through the center of the heater 9 and passes through the temperature controller 13 (not shown). Connected to. Here, the heater 9 is close to a part of the side surface of the coating tube 16 that constitutes the thermocouple 12, and is also relatively close to the temperature measuring unit 17 located at the tip of the thermocouple 12, so that the thermocouple is 12 is the susceptor 3
It is more susceptible to the temperature of the heater 9 than the temperature of. For example, when the temperature of the susceptor 3 is raised, the heater 9 needs to have a higher temperature than the susceptor 3, so that the influence is particularly remarkable. Further, when the heater 9 becomes high in temperature, the growth gas becomes corrosive, so that the cladding 16 of the thermocouple 12 is corroded and the wire 18 of the thermocouple 12 is exposed and the heater 9 is exposed at that location. The temperature is detected directly, making it impossible to measure the susceptor temperature accurately. As described above, if the susceptor temperature is not accurately measured, it becomes difficult to maintain the temperatures of the susceptor 3 and the substrate 4 constant. In addition, the coating tube 16 of the thermocouple 12 is corroded to cause a leak, and thereafter, the growth of the thin film cannot be performed at all, and there is a risk of causing an explosion by reacting with hydrogen in the reactor 1. There is also a nature.

[0007]

As described above,
In the conventional vapor phase growth apparatus, the temperature of the susceptor is not accurately measured due to the influence of the heater temperature, and it is difficult to maintain the temperature of the substrate during vapor phase growth at a constant level. The thermocouple cladding as a means is corroded,
Not only does the growth of the thin film become difficult due to the occurrence of leaks, but there is also the risk of reacting with the hydrogen in the reactor and causing an explosion.

Therefore, in the present invention, the above problems are solved,
The influence of the heater temperature on the thermocouple can be reduced, stable susceptor temperature can be measured, the thermocouple cladding tube can be prevented from being corroded, and a good-quality semiconductor thin film can be vapor-deposited. It is an object of the present invention to provide a vapor phase growth apparatus which is excellent in safety.

[0009]

In order to achieve the above object, in the present invention, a susceptor arranged in a reaction furnace, a substrate supported by the susceptor, and the substrate and the susceptor are heated. Heating means, and a temperature measuring means provided in the vicinity of the susceptor for measuring the temperature of the susceptor, while controlling the heating by the heating means by the output of the temperature measuring means, a thin film on the substrate. In the vapor phase growth apparatus for performing vapor phase growth, a member for cutting off heat from the heating means is provided on the outer periphery of the temperature measuring means, and heat from the heating means is cut off. The above-mentioned member for performing the above is provided via a predetermined space between the member and the temperature measuring means.

[0010]

In the vapor phase growth apparatus according to the present invention, the temperature is increased when the substrate and the susceptor are heated by providing the member for cutting off the heat by the heating means on the outer periphery of the temperature measuring means. It is possible to prevent the influence of the heating means from being directly reflected on the output of the temperature measuring means. Particularly, by providing a space between the cover and the temperature detecting means in the vicinity of the heating means, the heat insulating effect can be enhanced. With such a configuration, stable measurement of the susceptor temperature becomes possible.

Further, since it is possible to prevent the temperature of the temperature measuring means from becoming high in the vicinity of the heating means, there is no possibility that a part of the temperature measuring means is corroded by the growth gas. For this reason, there is no risk that it will be difficult to grow the thin film due to the occurrence of the leak or that the thin film will react with hydrogen in the reaction furnace to cause an explosion.

[0012]

Embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a schematic diagram showing the configuration of a vapor phase growth apparatus according to the present invention. Here, the same parts as those shown in FIG. 8 are designated by the same reference numerals.

A susceptor 3 supported by one end of a rotary support 2 is arranged in a reaction furnace 1, and a substrate 4 is provided on the susceptor 3.
Is placed. The other end of the rotary support 2 is connected to a motor 8 via pulleys 5, 6 and a belt 7. A heater 9 is attached to the lower portion of the susceptor 3 as a heating means for heating the substrate 4 via the susceptor 3, and a reflector plate 10 for reflecting the heat of the heater 9 is attached below the heater 9. There is. In order to maintain the substrate 4 at a constant temperature, the susceptor 3 is used to measure its temperature.
A recess 11 is provided in the lower center of the reactor, and a thermocouple 12 as a temperature measuring means is inserted into the recess 11 from the outside of the reaction furnace 1 through the central portions of the heater 9 and the reflection plate 10. The thermocouple 12 is connected to the temperature controller 13, and based on the output thereof, the heater 9 is connected by the temperature controller 13.
Temperature control is performed. Here, a protective cover 19 is provided on the outer circumference from the tip of the thermocouple 12 to the vicinity of the heater 9. The method of vapor-depositing a semiconductor thin film on the substrate 4 by the vapor-phase growth apparatus having the above-described configuration is the same as the method outlined in the related art, and therefore, a duplicate description is omitted here. I will. Next, the protective cover 1 provided on the outer periphery of the thermocouple 12
9 will be described in detail.

FIG. 2 is a partially enlarged view showing details of the temperature measuring portion of the susceptor in the vapor phase growth apparatus according to the present invention. The thermocouple 12 inserted in the recess 11 provided in the lower center of the susceptor 3 has a structure in which the temperature measuring unit 17 and the wire 18 are covered with the coating tube 16. Also, this thermocouple 12
A protective cover 19 is attached to the tip of the susceptor 3 inserted into the recess 11. The protective cover 19 is attached to the covering pipe 16 so as to be in close contact with it so as to cover the tip of the thermocouple 12 in the recess 11 of the susceptor 3. On the other hand, below the recess 11 of the susceptor 3, that is, in the vicinity of the heater 9, the skirt of the protective cover 19 widens so that a space is created between the coating tube 16 and the protective cover 19. Here, the protective cover 19 is
It is necessary to use a material (for example, molybdenum) that can withstand the heater temperature (about 950 ° C.) and has excellent corrosion resistance to the growth gas. The protective cover 19 may be fixed to the tip of the thermocouple 12, or may simply be supported. By providing the protective cover 19 as described above, the following effects can be obtained.

First, due to the above-mentioned protective cover 19,
The flow of heat from the heater 9 can be cut off to some extent, and the influence of the heater 9 having a high temperature is not directly reflected on the temperature measuring unit 17 of the thermocouple 12. In particular, in the vicinity of the heater 9, a space is provided between the protective cover 19 and the coating tube 16 to improve the heat insulating effect. With this configuration, it is possible to measure the susceptor temperature in a stable manner.

Second, the cladding tube 1 near the heater 9
Since it is possible to prevent the temperature of 6 from becoming high, there is no possibility that the cladding gas 16 will be corroded by the growth gas. Therefore, the wires 18 of the thermocouple 12 are not exposed, and there is no possibility that the temperature of the heater 9 that has become high is directly detected. In addition, there is no risk that the growth of the thin film will be difficult due to the occurrence of leak, or that there will be an explosion by reacting with hydrogen in the reaction furnace 1, and the safety of the apparatus will be improved. Figure 3
6 to 9 show modifications of the protective cover used in the vapor phase growth apparatus according to the present invention.

In FIG. 3, the protective cover 19 is divided into upper and lower parts,
The upper cover 19a is closely attached to the covering pipe 16 so as to cover the tip of the thermocouple 12, and the lower end thereof is attached to the lower cover 1.
It has the structure joined to the upper end inside of 9b. This allows
A predetermined space is provided between the lower cover 19b and the coating tube 16 of the thermocouple 12. As shown in FIG. 2, it is relatively difficult to mold the protective cover 19 with a single member, and it may occur that it is difficult to manufacture depending on the material. On the other hand, according to the configuration of the present modification, there is no difficulty in manufacturing. The materials of the upper cover 19a and the lower cover 19b may be the same or different. For example, a metal having a relatively good heat transfer characteristic is used for the upper cover 19 to improve the temperature measurement sensitivity in the vicinity of the susceptor 3, and a material having a poor heat transfer characteristic in the lower cover 19b arranged near the heater 9. By using, it is possible to adopt a configuration that improves the heat insulating effect.

In FIG. 4, a protective cover 19 is provided only near the heater 9 without providing a protective cover at the tip of the thermocouple 12 inserted into the recess 11 of the susceptor 3. Since the temperature measuring unit 17 is provided at the tip of the thermocouple 12, it is originally preferable not to attach the protective cover 19 in order to improve the temperature measurement sensitivity in the vicinity of the susceptor. However, it is dangerous not to provide the protective cover 19 at all because of the problem of corrosion resistance against growth gas. Therefore, in the case of the configuration like this modification, the thermocouple 1
The second cladding 16 itself must be made of a corrosion resistant material.

In FIG. 5, the protective cover 19 is not provided, but the central portion of the susceptor 3 is formed in a tubular shape, and the protective cover 19 is configured to cover the thermocouple 12 up to the vicinity of the heater. According to this structure, the protective cover 1 is attached to the tip of the thermocouple 12.
Since it is not necessary to mount 9, the temperature measurement sensitivity in the vicinity of the susceptor 3 can be improved, and the heat insulating effect described above can be obtained. The cylindrical protective cover 19 in this modification may be integrally formed with the susceptor 3 as shown in FIG. 5, or may be separately provided as shown in FIG.

FIG. 7 is a partial cross-sectional view showing the shape of the recess provided in the lower center of the susceptor for inserting the tip of the thermocouple in the vapor phase growth apparatus according to the present invention.
As shown in FIGS. 7A to 7C, the shape of the concave portion 11 is not particularly limited, and the temperature measuring portion 17 of the thermocouple 12 is provided in the area.
It suffices if it is configured so that is securely inserted.

According to the vapor phase growth apparatus according to the present invention described above, the temperature of the substrate 4 during the vapor phase growth can be maintained substantially constant, so that an extremely stable and high quality semiconductor thin film can be formed. As a result, even when the manufactured semiconductor is used as a laser diode or the like, it is possible to make its various characteristics uniform.

[0022]

As described above, according to the present invention,
Since the temperature of the susceptor can be stably measured and the substrate temperature during vapor phase growth can be maintained substantially constant, it is possible to provide a vapor phase growth apparatus capable of forming a semiconductor thin film of extremely good quality.

Further, since it is possible to prevent corrosion of the thermocouple, which is the temperature measuring means, by the growth gas, it is difficult to grow the thin film due to the occurrence of leakage, or there is a risk of explosion due to reaction with hydrogen in the reaction furnace. Since the property is also lost, it is possible to provide a vapor phase growth apparatus having excellent safety.

[Brief description of drawings]

FIG. 1 is a schematic diagram showing a configuration of a vapor phase growth apparatus according to the present invention.

FIG. 2 is a partially enlarged view showing details of a temperature measuring unit of a susceptor in the vapor phase growth apparatus according to the present invention.

FIG. 3 is a view showing a modified example of a protective cover used in the vapor phase growth apparatus according to the present invention.

FIG. 4 is a view showing a modified example of a protective cover used in the vapor phase growth apparatus according to the present invention.

FIG. 5 is a view showing a modified example of the protective cover used in the vapor phase growth apparatus according to the present invention.

FIG. 6 is a view showing a modified example of the protective cover used in the vapor phase growth apparatus according to the present invention.

FIG. 7 is a partial cross-sectional view showing the shape of a recess provided in the lower center of the susceptor for inserting the tip of the thermocouple in the vapor phase growth apparatus according to the present invention.

FIG. 8 is a schematic diagram showing the configuration of a conventional vapor phase growth apparatus.

FIG. 9 is a partially enlarged view showing an outline of a susceptor temperature measuring unit in a conventional vapor phase growth apparatus.

[Explanation of symbols]

 1 Reactor 2 Rotation Support 3 Susceptor 4 Substrate 5,6 Pulley 7 Belt 8 Motor 9 Heater (Heating Means) 10 Reflector 11 Recess 12 Thermocouple (Temperature Measuring Means) 13 Temperature Controller 14 Heater Electrode 15 Gas Inlet 16 Coating Tube 17 Thermocouple temperature measuring part 18 Thermocouple wire 19 Protective cover

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Yusuke Sato Inventor, Komukai Toshiba Town No. 1, Komukai Toshiba Town, Kawasaki City, Kanagawa Prefecture Toshiba Research and Development Center

Claims (2)

[Claims] 1. A susceptor disposed in a reaction furnace, a substrate supported by the susceptor, heating means for heating the substrate and the susceptor, and the susceptor for measuring the temperature of the susceptor. In the vapor phase growth apparatus for vapor-depositing a thin film on the substrate while controlling the heating by the heating means by the output of the temperature measuring means, the temperature measuring means of the temperature measuring means A vapor phase growth apparatus characterized in that a member for blocking heat from the heating means is provided on the outer periphery. 2. The vapor phase growth according to claim 1, wherein the member for blocking heat from the heating means is provided with a predetermined space between the member and the outer circumference of the temperature measuring means. apparatus.