JPH0744155B2 - Wafer rotary vapor phase growth equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to vapor phase growth in which a film is formed on a wafer while rotating the wafer in a flow of a reaction gas and heating a susceptor on which the wafer is placed. More specifically, it relates to the apparatus, and more specifically, is perpendicular to the axis of the rotary shaft, which is supported by the inner end of the reaction tube of the rotary shaft that penetrates the reaction pipe through which the reaction gas flows from the outside in an airtight manner and almost perpendicular to the flow of the reaction gas. The present invention relates to a wafer rotation type vapor phase growth apparatus in which a wafer is placed on a susceptor having a different mounting surface and the susceptor is heated while rotating the wafer via the rotation shaft to form a film on the wafer.

[Conventional technology]

When a film is formed on the wafer surface by vapor phase growth, the wafer should be rotated around an axis within the surface and perpendicular to the surface to change the relative position to the reaction gas flow to achieve uniform film thickness. Is widely practiced. In addition, when forming a film, it is necessary to keep the wafer at a wafer temperature sufficient to cause thermal decomposition of the reaction gas, for example, 800 ° C. The susceptor on which the wafer is placed is energized by high-frequency induction heating by passing a high-frequency current through a coil that surrounds the outer peripheral surface of the reaction tube, and by using an infrared lamp the outside of the reaction tube Radiation heating is generally used, or a method in which a slip ring and a brush are used to supply heating power to a heater disposed in proximity to the susceptor using a rotating shaft that rotates the wafer is generally used.

[Problems to be Solved by the Invention]

However, the configurations of these heating systems have the following drawbacks. That is, in the case of high-frequency induction heating in which a high-frequency current is applied to a coil that surrounds the outer peripheral surface of the reaction tube, a frequency of several tens of kHz to several MHz is supplied as the frequency for supplying the power required to heat the susceptor. In order to generate such a high-frequency large current, an expensive power supply device is required. Furthermore, the frequency in this range overlaps with the frequency used for wireless communication, and the electric power is as high as hundreds of watts or tens of kilowatts, which is as high as that of high-power broadcasting equipment, so careful radio wave leakage to prevent interference with wireless communication. It is necessary to take preventive measures.

In the case of radiant heating with an infrared lamp, there are few disadvantages as described above, but due to structural restrictions and the physical size of the lamp that is the infrared source, infrared rays can be efficiently applied to the susceptor. There are drawbacks such as difficulty, low heating efficiency, and high power consumption.

Further, in the case where the slip ring and the brush are used, the heater is arranged close to the susceptor, and the heating efficiency is high and the cost is low. However, the wear of the brush and the slip ring, and the problems such as maintenance inspection and replacement work associated therewith. There is a possibility that trouble may occur due to poor contact or the like, and there is a problem that it is not necessarily suitable for stable operation of the device for a long period of time.

An object of the present invention is to eliminate the drawbacks and problems in the configuration of the conventional heating system described above, and to improve the heating efficiency to reduce the cost required for the configuration of the heating system for heating, and to provide a heated susceptor. It is an object of the present invention to provide a structure of a heating system of a wafer rotary vapor phase epitaxy apparatus that can easily perform temperature monitoring and temperature control of a susceptor therewith.

[Means for Solving the Problems]

In order to solve the above-mentioned problems, according to the present invention, a reaction tube in which a reaction gas flows is supported from the outside by an end portion inside a reaction tube of a rotary shaft that is airtight from the outside and substantially perpendicular to the flow of the reaction gas. A wafer is placed on a susceptor having a mounting surface perpendicular to the axis of the rotating shaft, and the wafer is rotated through the rotating shaft to heat the susceptor to form a film on the wafer. The structure of the susceptor heating system in the apparatus is such that the rotating shaft is formed hollow and a heating means for heating the susceptor is integrally provided with the rotating shaft on the side opposite to the wafer of the susceptor. 2 of a rotary transformer in which a primary winding side and a secondary winding side are formed coaxially and relatively rotatable about an axis
A susceptor having a configuration in which the secondary winding side is fixed coaxially, supplies heating power to the heating means via the secondary winding, and is supported at the tip of the reaction tube of the rotary shaft in the heating system of the configuration. As a surrounding structure, the susceptor is supported via a susceptor mounting table that is integrated with a heat insulator fixed to the tip of the rotating shaft, and heating means for heating the susceptor is provided on the side opposite to the susceptor mounting table. A heating power supplied to the heating means by being fixed and having a temperature measurement sensor attached to the susceptor mounting table or the susceptor, and extracting the signal output of the temperature measurement sensor from a portion of the rotary shaft outside the reaction tube. If possible, it shall be possible to control.

[Action]

By configuring the wafer rotary vapor phase growth apparatus in this way, the heating power is supplied from the fixed part outside the reaction tube to the part that rotates integrally with the susceptor without causing friction or wear, and causing trouble due to poor contact. It is always possible without fear. Further, with such a configuration, the susceptor heating means that receives the supply of heating power is arranged in proximity to the susceptor, so that the susceptor mounting table on which the susceptor is mounted is supported from the rotating shaft through the thermal insulator. By
The heating efficiency is remarkably improved as compared with the case of conventional infrared heating. Further, since the temperature measuring sensor attached to the susceptor mounting table or the susceptor can be easily pulled out to the outside of the reaction tube through the hollow rotating shaft, the heating power supplied to the susceptor heating means can be easily controlled.

〔Example〕

FIG. 1 shows an embodiment of the structure of a wafer rotary type vapor phase growth apparatus according to the present invention. The reaction tube 1 has a reaction gas inlet 2 at the left end and a reaction gas outlet 3 at the right end, and has a branch pipe 4 which branches from an intermediate position between the reaction gas inlet 2 and the reaction gas outlet 3 and extends downward. . At the lower end of the branch pipe 4, a susceptor rotating shaft 5 which is made hollow and is introduced almost perpendicularly to the gas flow in the reaction tube 1 is rotatable by a gas seal 6 and a bearing 7 while maintaining gas tightness. Is configured.

On the upper part of the susceptor rotating shaft 5, a susceptor mounting table 9 is mounted via a thermal insulator 8 made of ceramics or the like so that the mounting surface of the susceptor is perpendicular to the axis of the susceptor rotating shaft 5. A heater 10 is provided on the surface opposite to the surface. Further, the susceptor mount 9 has a thermocouple 11
Is attached.

On the other hand, at the tip of the susceptor rotating shaft 5 on the atmosphere side, the secondary winding side of the rotary transformer 14, which is formed so that the primary winding side and the secondary winding side are coaxial and is rotatable relative to the axis, is coaxial. The secondary winding 14b of the heater 10 is connected to the extraction cable 12 of the heater 10. Further, the primary winding 14a of the rotary transformer 14 is supported by a bearing 15 via a frame accommodating the primary winding so as not to move axially relative to the secondary winding side, and the primary winding side frame is It is non-rotatably fixed to a fixed member in the vicinity by a rotation stopper fitting 16.

The output signal of the thermocouple 11 has a weak signal power, and it has been found that there is no practical problem within the range of the technology used so far.Therefore, the lead wire 13 and the signal slip ring 19, contact It is guided to the outside by the child 20 and the temperature measuring instrument 21
Entered in. The temperature measuring device 21 outputs a temperature signal 22 having a one-to-one correspondence with the signal power input from the thermocouple 11, and the power controller 18 to which the temperature signal 22 is input rotates from the heating power supply 17. The electric power supplied to the heater 10 via the transformer 14 is controlled so that the temperature of the susceptor mounting table 9 is kept constant at a set value.

At the atmospheric side of the susceptor rotating shaft 5, a pulley 23 is further provided.
The susceptor rotation shaft 5 is provided with a variable speed motor 25 via a toothed belt 24 to provide an appropriate rotation speed, for example, 10 rpm to
It can be rotated at 00 rpm.

When a film is formed on a wafer by the wafer rotary vapor deposition apparatus having the heater heating system and the susceptor mounting table temperature control system as described above, the susceptor mounting table 9 is made of a material such as graphite or molybdenum. The susceptor 26 thus placed is placed, and a wafer 27 such as a semiconductor to be film-formed is placed on the susceptor 26.

〔The invention's effect〕

As described above, according to the present invention, the reaction tube in which the reaction gas flows is internally supported from the outside by the tip end portion of the reaction tube of the rotary shaft that penetrates airtightly and substantially perpendicular to the flow of the reaction gas. A wafer rotary-type vapor phase growth apparatus in which a wafer is mounted on a susceptor having a mounting surface perpendicular to the axis of a rotating shaft, and the wafer is rotated via the rotating shaft to heat the susceptor to form a film on the wafer. In the configuration of the susceptor heating system in, the rotating shaft is formed in the hollow and heating means for heating the susceptor is integrally provided with the rotating shaft on the side opposite to the wafer of the susceptor, and a portion of the rotating shaft outside the reaction tube. The primary winding side and the secondary winding side are coaxial and the secondary winding side of a rotary transformer formed so as to be relatively rotatable about the axis is fixed coaxially to the secondary winding side. To the heating means via Since power is supplied to the internal part of the reaction tube that rotates integrally with the susceptor from the fixed part outside the reaction tube, there is no friction or wear as in the case of using the slip ring and brush, and due to poor contact. It became possible without fear of trouble and enabled stable operation over a long period of time. Further, in the heating system configuration of the present invention, the susceptor mounting table is supported from the rotating shaft through the thermal insulator, the susceptor heating means is directly fixed to the susceptor mounting table, and the heating power is supplied to the susceptor heating means through the inside of the hollow rotating shaft. The heating efficiency can be remarkably improved as compared with the case of the conventional infrared heating, and the heating system can be configured without much cost. Moreover, in the susceptor heating system of this structure, as a structure around the susceptor supported by the inner end of the reaction tube of the rotary shaft, the susceptor is integrated with the heat insulator fixedly mounted on the front end of the rotary shaft as described above. The heating means, which is supported through the susceptor mounting table and heats the susceptor, is fixed to the side opposite to the susceptor side of the susceptor mounting table, and the temperature measuring sensor is attached to the susceptor mounting table or the susceptor. Since the power supply to the heating means can be easily controlled by taking out the signal output of the measurement sensor from a portion outside the reaction tube of the rotary shaft, the heating efficiency is high and the heating efficiency is high for a long period of time. There is a merit that a wafer rotary-type vapor phase growth apparatus that can be operated stably and that can easily control the electric power supplied to the heating means can be constructed at low cost. .

[Brief description of drawings]

FIG. 1 is an explanatory sectional view showing an embodiment of the structure of a wafer rotary vapor phase growth apparatus according to the present invention. 1: Reaction tube, 4: Branch tube, 5: Susceptor rotating shaft (rotating shaft), 8:
Thermal insulator, 9: susceptor mounting table, 10: heater (heating means), 11: thermocouple (temperature measurement sensor), 14: rotary transformer,
14a: primary winding, 14b: secondary winding, 17: heating power supply, 18: power controller, 21: temperature measuring device, 22: temperature signal, 26: susceptor, 27: wafer.

Claims (2)

[Claims] 1. A mount perpendicular to the axis of a rotary shaft, which is supported by a distal end of the rotary shaft inside a rotary shaft that penetrates a reaction pipe through which a reactive gas flows from the outside in a gas-tight manner and substantially perpendicular to the flow of the reactive gas. A wafer is mounted on a susceptor having a mounting surface, and in the wafer rotary vapor phase growth apparatus that heats the susceptor while rotating the wafer through the rotating shaft to form a film on the wafer, the rotating shaft is hollow. A heating means that is formed and heats the susceptor is integrally provided with the rotating shaft on the side opposite to the wafer side of the susceptor, and the primary winding side and the secondary winding side are provided at a portion of the rotating shaft outside the reaction tube. A secondary winding side of a rotary transformer formed coaxially and capable of relative rotation about an axis is fixed coaxially, and heating power is supplied to the heating means via the secondary winding. Wafer rotary vapor phase growth system 2. The wafer rotary-type vapor phase growth apparatus according to claim 1, wherein the susceptor supported by the tip of the rotary shaft in the reaction tube is a thermal insulator fixed to the tip of the rotary shaft. The heating means, which is supported through an integrated susceptor mounting table and heats the susceptor, is fixed to the side opposite to the susceptor side of the susceptor mounting table, and a temperature measuring sensor is attached to the susceptor mounting table or the susceptor. A wafer rotating type vapor phase growth apparatus, characterized in that a signal output of a sensor is taken out from a portion of a rotary shaft outside a reaction tube to control electric power supplied to the heating means.