JPH0246047Y2 - - Google Patents

Description

[Detailed description of the invention] [Description of the technical field to which the invention pertains] The present invention relates to a crystal growth apparatus with a rapid cooling mechanism.

[Description of prior art]

In liquid-phase epitaxial growth of compound semiconductors, a jig made of high-purity graphite (hereinafter referred to as a carbon boat) is generally used. Carbon boats have a relatively large heat capacity and require time to cool down even after growth is complete, and the heated state continues during this time.

If the growth substrate is heated for a long time, thermal decomposition of the material itself or loss of the doping material may occur.
This causes so-called thermal deterioration, which impairs the characteristics of the device.

For this reason, in the past, a structure was mainly used in which cooling air was flowed between the furnace body and the furnace core tube, but with this method, it took 3 to 5 hours to cool the furnace to room temperature. .

[Explanation of the purpose of the invention]

The present invention provides an apparatus that cools the growth substrate immediately after epitaxial growth to prevent thermal deterioration.

[Structure of the idea]

The present invention is a horizontal crystal growth apparatus consisting of a quartz reaction tube and a furnace body that surrounds and heats the quartz reaction tube. and a casing that surrounds the outer periphery of the furnace body, and a first fan that sucks air from outside the casing and forcibly blows it onto the quartz reaction tube.
A second fan is installed opposite the first fan and forcibly exhausts the air that has been heat exchanged with the quartz reaction tube, and a second fan is installed near the second fan to cool the exhausted air. This is a crystal growth apparatus with a rapid cooling mechanism, characterized by having a radiator.

[Explanation of Examples]

An embodiment of the present invention will be described below with reference to the drawings.

In FIGS. 1 and 2, the quartz reaction tube 2 is held horizontally in a cantilevered manner and is housed in the housing 1, while the furnace body 7 for heating the quartz reaction tube 2 is moved into the slide mechanism. 8 so as to be movable in the axial direction of the reaction tube 2. Furthermore, a first fan 4 is installed on one side of the quartz reaction tube 2 to suck air from outside the casing 1 and blow it onto the quartz reaction tube 2, while forcing air heat exchanged in the reaction tube 2 to the other side. A second fan 5 is installed to exhaust the air. On the suction side of the second fan 5, a radiator 6 for cooling air to be exhausted outside the housing is installed.

The radiator 6 is a water-cooled radiator for preventing the air that has cooled the reaction tube 2 from being exhausted to the outside of the housing while remaining at a high temperature. 3 is a carbon boat on which a growth substrate is placed, and the carbon boat 3 is installed inside the reaction tube 2.

During epitaxial growth, the furnace body 7 is set at the use position A, surrounds the reaction tube 2 and heats it, and the growth is performed according to a predetermined sequence. Next, at the same time as the growth is completed, the furnace body 7 is moved to B by the slide mechanism section 8.
to the standby position to expose the reaction tube. At this time, by rotating both fans 4 and 5, air is guided into the housing 1 by the first fan 4, cools the reaction tube 2, exchanges heat with the radiator 6, and is exhausted from the second fan 5. be done.

[Explanation of the effects of the invention] As explained above, according to the invention, the amount of suction and exhaust air can be balanced, the flow rate and flow rate around the outer circumference of the reaction tube can be large, and a device with high cooling effect can be realized. Therefore, the temperature of the carbon boat can be lowered from about 800°C, which is the temperature at which growth is completed, to room temperature in about 60 minutes. Therefore, not only can thermal deterioration of the growth substrate be suppressed as much as possible, but
The cooling time before taking out the boat, which was originally useless in the growth process, can be significantly shortened, and the operating cycle of the equipment can be increased, contributing to improved productivity.

Furthermore, there is no need to significantly increase or decrease the temperature from the growth temperature to room temperature in each growth cycle, which has the effect of reducing damage to the furnace body and improving the reproducibility and stability of the furnace temperature.

[Brief explanation of the drawing]

FIG. 1 is a block diagram illustrating the main parts of the present invention, and FIG. 2 is an overall block diagram of the apparatus of the present invention. 1... Housing, 2... Quartz reaction tube, 3... Carbon boat, 4... First fan, 5... Second fan, 6... Water-cooled radiator, 7... Furnace body, 8
...Slide mechanism section.

Claims (1)

[Scope of utility model registration request] In a horizontal crystal growth apparatus comprising a quartz reaction tube and a furnace body that surrounds and heats the quartz reaction tube, the slide mechanism section moves the furnace body in the axial direction of the quartz reaction tube, the quartz reaction tube and the furnace body. A casing surrounding the outer periphery of the quartz reaction tube, a first fan that sucks air from outside the casing and forcibly blows it onto the quartz reaction tube; A crystal growth apparatus with a rapid cooling mechanism, comprising: a second fan that forcibly exhausts air; and a radiator that is installed near the second fan and cools the exhausted air.