JP2006165450A - Device and method for forming semiconductor film - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a semiconductor film forming device and a semiconductor film forming method by which a semiconductor crystal film is formed at a constant growth rate without being contaminated with dust or the like and the process efficiency of the crystal film is improved, when the crystal film is formed by supplying a source gas to the surface of a heated substrate to be processed. <P>SOLUTION: Substrates 14 to be processed are supported and fixed on disc-shape susceptors 16 so that they may be spaced and opposed from and to one another. The source gas is introduced to a gap between the opposed susceptors 16 from the center of each of the susceptors. The introduced source gas is flowed from the center of each susceptor 16 toward the edge of its circumference by rotating the disc-shape susceptors 16 and is used for film forming processing on the substrates 14 to be processed which are heated to a high temperature. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a semiconductor film forming apparatus and a semiconductor film forming method for forming a desired crystal film on a surface of a substrate by spraying a source gas, and more particularly to an apparatus and method for growing a crystal film of a nitrogen compound.

  Gallium nitride is suitably used for currently used blue LED light emitting elements. As for this gallium nitride, a crystal film is generated by metal organic chemical vapor deposition (MOCVD) or the like. At that time, since the performance of the light-emitting element depends on the accuracy of the crystal film, it is desired that the crystal film is generated at a constant growth rate and that the generated crystal film has excellent crystallinity without lattice defects. ing. Further, in order to produce a large amount of crystal film, improvement in productivity is also desired.

The crystal film of gallium nitride has a very high film formation temperature of 1000 ° C. or higher, so that heat convection easily occurs and it is difficult to supply a sufficient amount of source gas on the film formation surface on the substrate. .
In the following Patent Document 1, a reactive gas (raw material gas) is supplied in a direction parallel to or inclined with respect to the surface of the substrate, while an inert gas is supplied as a pressing gas from a direction substantially perpendicular to the surface of the substrate. Thus, a semiconductor crystal film growth method is proposed in which the crystal film is grown by changing the spray direction of the reaction gas to the direction of the substrate surface.
In this method, since the reaction gas can be maintained on the substrate surface using the pressure gas, it is possible to suppress the decrease in the growth rate of the crystal film and the stop of the growth caused by the material gas floating from the substrate in the high temperature state. it can.

Japanese Patent No. 2628404

However, even with the above method, there are cases in which a crystal film with high accuracy cannot always be generated. Specifically, fine particles having the same components as the crystal film are mixed into the crystal film as dust or attached to the surface of the generated crystal film.
Such a dust problem occurs when a crystal film is generated in the reaction vessel, and a part of the crystal film of the source gas adhering to the ceiling surface of the reaction vessel is peeled off and dropped onto the substrate.

  Therefore, in order to solve the above-described problems, the present invention provides a crystal film without being contaminated by dust or the like when supplying a raw material gas to the surface of a heated processing substrate to generate a semiconductor crystal film. A semiconductor film forming apparatus and a semiconductor film forming method in which a film is generated at a constant growth rate, the generated crystal film has excellent crystallinity without lattice defects, and the processing efficiency of the crystal film is improved. The purpose is to provide.

  In order to achieve the above object, the present invention provides a semiconductor film forming apparatus for generating a semiconductor crystal film by supplying a raw material gas to the surface of a heated processing substrate, and a reaction for generating a semiconductor crystal film on the processing substrate. Two support plates for supporting and fixing a plurality of processing substrates, which are arranged to face each other with a gap in the reaction vessel so that the container and the substrate surface of the processing substrate face each other with a predetermined gap. And an inlet for introducing a source gas from the outside of the reaction vessel into the gap between the opposing support plates provided in the center of each of the two support plates, and a source gas introduced into the gap And a flow rate forming means for flowing from the introduction port toward the ends of the two support plates.

The two support plates have a disc shape, the introduction port is provided at the center of the disc shape, and the flow velocity forming means passes through the introduction port and is orthogonal to the surfaces of the two support plates. It is a rotation mechanism that rotates and drives the two support plates around the center axis that rotates, and it is preferable that the source gas flows toward the outer circumference of the two support plates by rotating the two support plates. .
At that time, the rotation of the two support plates is, for example, 100 to 1000 rpm. Moreover, the said gap | interval is 1-10 mm, for example.
Further, a plurality of processing substrates are concentrically arranged on the two support plates, and separately from the two support plates so as to heat the concentric processing substrates arranged outside the gap. It is preferable that the substrate heater is provided concentrically as the body.

  Furthermore, the present invention is a semiconductor film forming method for generating a semiconductor crystal film by supplying a source gas to the surface of a heated processing substrate, wherein the substrate surfaces of the processing substrate face each other with a predetermined gap therebetween. As described above, a step of supporting and fixing a plurality of processing substrates to two support plates, a step of introducing a source gas into the gap between the opposite support plates from the center of each of the two support plates, and the gap And a step of flowing the source gas introduced to the end of the two support plates from the introduction port.

In the present invention, the processing substrates are arranged on the support plate so as to face each other with a predetermined gap, and a raw material gas is introduced into the narrow gap between the support plates from each central portion of the support plate. Gas is allowed to flow toward the edge of the support plate. Since the processing substrate is disposed on both sides of the flow path of the source gas, when the source gas approaches the heated processing substrate, even if the source gas is subjected to a movement such that the source gas is separated from one processing substrate, the other Therefore, the source gas can be used effectively, and the crystal film can be generated efficiently.
In addition, since the processing substrates are arranged on both sides of the flow path of the source gas, the ceiling where the crystal film of the source gas adheres to the wall surface surrounding the flow path and a part of it is separated as dust and particles. There are no walls. For this reason, the crystal film produced | generated by dust etc. is not polluted.
Furthermore, the support plate is shaped like a disc, and the support plate is rotated around the center of the disc as the center of rotation.
The temperature distribution generated by heating with the heater and the flow velocity distribution of the source gas are axisymmetric, and the conditions for film formation performed on the processing substrate arranged concentrically on the support plate are the same for all the processing substrates. . For this reason, a crystal film is generated at a constant growth rate.
Further, since the flow path for flowing the source gas between the opposing processing substrates is narrowed, the reaction vessel itself used for the semiconductor film forming apparatus can be made small. In addition, since the film forming process is performed with the support plates that support and fix the processing substrate facing each other, the amount of film forming process is doubled compared to the conventional case.

  Hereinafter, a semiconductor film forming apparatus and a semiconductor film forming method of the present invention are one embodiment of the present invention, and are described in detail based on an MOCVD (metal organic chemical vapor deposition) apparatus that suitably performs the semiconductor film forming method of the present invention. Explained.

  FIG. 1 is a schematic configuration diagram of a MOCVD (metal organic chemical vapor deposition) apparatus 10 which is an embodiment of a semiconductor film forming apparatus of the present invention.

  The MOCVD apparatus 10 includes a reaction vessel 12, a pair of susceptors (support plates) 16 that support and fix a processing substrate 14 provided in the reaction vessel 12 at a predetermined position, and an annular rotation that supports the susceptor 16. A shaft 18, provided in the rotary shaft 18, provided in the central portion of the susceptor 16 and introduced from the introduction pipe 20, provided in the central portion of the susceptor 16, which introduces the raw material gas into the reaction container from the outside of the reaction container 12. Connected to an inlet 22 for introducing the source gas into the gap between the pair of susceptors 16, a heater 24 that is provided separately from the susceptor 16 and that heats the processing substrate 14, and a vacuum pump (not shown) that exhausts the source gas and the like. The exhaust port 26 is provided. The rotating shaft 18 is connected to a motor 28, and the susceptor 16 is rotated via the rotating shaft 18.

The reaction vessel 12 is made of stainless steel, and the rotary shaft 18 extends outside the reaction vessel 12 and is connected to the motor 28.
The processing substrate 14 is, for example, a sapphire substrate, and a crystal film is generated on the substrate by using a source gas such as trimethylgallium (TMG) or ammonia (NH ₃ ).
Each of the pair of susceptors 16 has a disk shape as shown in FIG. 2, and stands vertically in the reaction vessel 12. A plurality of disk-shaped processing substrates 14 are concentrically arranged on the susceptor 16. Supported and fixed. That is, the pair of susceptors 16 are provided in the reaction container 12 so as to face each other such that the processing substrate 14 to be supported and fixed faces the inside of the susceptor 16. The gap between the susceptors 16 is 1 to 10 mm. The size of the susceptor 16 is, for example, 100 to 500 mm in diameter.

  The pair of susceptors 16 are supported by the rotating shaft 18 so as to rotate at a predetermined speed. The heater 24 is a heater that heats the processing substrates 14 that oppose each other via the susceptor 16, and is provided as a separate concentric circle so as not to contact the disc-shaped susceptor 16. The heater 24 heats the processing substrate 14 to a high temperature of 1000 ° C. or higher. For this reason, the susceptor 16 is made of a carbon material whose surface is coated with SiC that is sufficiently durable even when exposed to high temperatures and that does not contaminate the source gas in the reaction vessel 12.

  The introduction pipe 20 provided in the rotation shaft 18 is connected to an introduction port 22 provided in the susceptor 16, and the introduction pipe 20 is stationary with respect to the susceptor 16 that rotates together with the rotation shaft 18. Thus, the connection mechanism is provided, and the vacuum shield is held. One end of the introduction pipe 20 is connected to a supply pipe (not shown) connected to the source gas source.

The exhaust port 26 is provided in a portion of the reaction vessel 12 where the gap between the susceptors 16 is extended, and the remaining source gas that has passed through the gap between the susceptors 16 is forcibly exhausted. A plurality of exhaust ports 26 are provided on the periphery of the rotating susceptor 16.
The motor 28 is provided to rotate the susceptor 16 at a predetermined speed, and is driven to rotate at, for example, 100 to 1000 (rpm).

The reason why the processing substrate 14 is rotated by rotating the susceptor 16 is to rotate the raw material gas introduced from the introduction port 22 to give a flow velocity from the central portion of the disk-shaped susceptor 16 toward the outside. is there. Moreover, since the processing substrate 14 rotates, the flow of the source gas can be evenly received on the circumference.
In the MOCVD apparatus 10 shown in FIG. 1, the susceptor 16 is erected in the vertical direction in the figure, but may be provided in the horizontal direction.

In such an MOCVD apparatus 10, first, the processing substrate 14 is concentrically arranged and supported and fixed to both the pair of susceptors 16. As a result, the processing substrate 14 is arranged to face each other with a gap therebetween.
Next, while supplying the source gas from the introduction pipe 20 to the gap between the pair of susceptors 16 in this state, the motor 28 is driven to rotate the susceptor 16 at a predetermined rotational speed. At that time, the remaining raw material gas is exhausted from the exhaust port 26, and the inside of the reaction vessel 12 is depressurized to a predetermined pressure.
Furthermore, the heater 24 is heated to heat the processing substrate 14 to 1000 ° C. or higher.

The rotational speed of the susceptor 16 is 100 to 1000 rpm, and the gap between the pair of susceptors 16 is as narrow as 1 to 10 mm. For this reason, the raw material gas supplied from the introduction port 22 is dragged by the rotation of the susceptor 16 to give a flow velocity of the rotational component. As shown in FIG. It flows toward (outside). The flow rate of the source gas is, for example, 20 to 30 (cm / second). The processing substrate 14 is heated to a high temperature by the heater 24 and faces through a narrow gap of 1 to 10 mm between the pair of susceptors 16. For this reason, even if the source gas flows away from the processing substrate 14 on one side due to thermal convection due to the thermal expansion of the source gas, the source gas approaches the opposite processing substrate 14 on the other side. It can be used effectively for the growth of the crystal film of the substrate 14. Further, since the gap is as narrow as 1 to 10 mm, the movement of the raw material gas due to convection is also limited.
Conventionally, in order to prevent the conventional source gas from being heated and expanded by the high-temperature processing substrate 14 and becoming difficult for the source gas to pass through the surface of the processing substrate 14 due to thermal convection, a press for pressing the source gas against the processing substrate 14 is performed. Gas was used.

Further, since the processing substrate 14 is heated by the heater 24 from both sides of the gap between the susceptors 16 serving as the raw material gas flow path and the processing substrate 14 is disposed on both sides, the processing substrate 14 is fixed to the ceiling or the like of a conventional reaction vessel. The film of the raw material gas and its fine particles are not peeled off and attached to the processing substrate 14. For this reason, the crystal film produced | generated on the process board | substrate 14 is very rarely contaminated with dust and particles.
In addition, the introduction port 22 is provided at the center of the rotating susceptor 16, the processing substrate 14 is concentrically disposed on the susceptor 16, and the heater 24 is also concentrically disposed so as to correspond to the flow and temperature distribution of the source gas. Also has axial symmetry. For this reason, all the processing substrates 14 arranged on the rotating susceptor 16 are exposed to a high-temperature source gas atmosphere having the same flow rate. Thereby, the film formation conditions of the processing substrate 14 become the same, and a uniform crystal film can be generated.

  Furthermore, since the gap between the pair of susceptors 16 is narrowed, the internal volume of the reaction vessel 12 itself can be reduced. Further, since the processing substrate 14 is disposed on both sides of the flow path of the source gas, the processing amount is improved twice as compared with the conventional case.

  As described above, the semiconductor film forming apparatus and the semiconductor film forming method of the present invention have been described in detail. However, the present invention is not limited to the above-described embodiments, and various improvements and modifications can be made without departing from the gist of the present invention. Of course it is also good.

It is a schematic block diagram of the MOCVD apparatus which is one Embodiment of the semiconductor film-forming apparatus of this invention. It is a figure which shows arrangement | positioning of the process board | substrate on the support plate in the semiconductor film-forming apparatus of this invention, and the flow of source gas. It is a figure which shows the flow of the source gas in the semiconductor film-forming apparatus of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 MOCVD apparatus 12 Reaction container 14 Processing substrate 16 Susceptor 18 Rotating shaft 20 Introducing pipe 22 Introducing port 24 Heater 26 Exhaust port 28 Motor

Claims (4)

A semiconductor film forming apparatus for generating a semiconductor crystal film by supplying a source gas to the surface of a heated processing substrate,
A reaction vessel for producing a semiconductor crystal film on a processing substrate;
Two support plates for supporting and fixing a plurality of processing substrates, which are arranged to face each other with a gap in the reaction vessel so that the substrate surfaces of the processing substrates face each other with a predetermined gap therebetween;
An inlet for introducing a raw material gas from the outside of the reaction vessel into the gap between the opposing support plates provided at the center of each of the two support plates;
And a flow rate forming means for flowing the source gas introduced into the gap from the inlet toward the ends of the two support plates. The two support plates have a disc shape, and the introduction port is provided at the center of the disc shape,
The flow velocity forming means is a rotation mechanism that rotates the two support plates around the center axis orthogonal to the surfaces of the two support plates through the introduction port, and rotates the two support plates. The semiconductor film forming apparatus according to claim 1, wherein the source gas is caused to flow toward the outer circumference of the two support plates. A plurality of processing substrates are concentrically arranged on the two support plates,
3. The semiconductor according to claim 2, wherein a heater for heating the substrate is provided concentrically as a separate body from the two support plates so as to heat the processing substrate arranged concentrically outside the gap. Deposition device. A semiconductor film forming method for generating a semiconductor crystal film by supplying a source gas to the surface of a heated processing substrate,
Supporting and fixing a plurality of processing substrates to two support plates so that the substrate surfaces of the processing substrates face each other with a predetermined gap;
Introducing a source gas into the gap between the opposing support plates from the center of each of the two support plates;
And a step of flowing the source gas introduced into the gap from the inlet toward the ends of the two support plates.

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