JPH0710689A - Device for growth of semiconductor in gaseous phase - Google Patents

Abstract

PURPOSE:To provide a semiconductor gas phase growth device enabling the formation of a crystal thin film good in the uniformity of the film thickness, the quality, etc., on plural simultaneously treated growth substrates in improved productivity. CONSTITUTION:A semiconductor gas phase growth device having a mechanism for substantially horizontally holding plural growth substrates 4 in a reaction oven 1 and for revolving the plural substrates at a rate of 300-2000rpm on a revolution shaft is characterized in that a revolution susceptor for holding the growth substrates 4 is a doughnut-shaped susceptor 10 and that a disk 11 is rotatably disposed in the central hole of the doughnut.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor vapor phase growth apparatus for enhancing the uniformity of a crystal film produced when a crystal thin film is vapor-phase grown on a plurality of substrates to be grown at the same time.

[0002]

2. Description of the Related Art A conventional semiconductor vapor phase growth apparatus will be described with reference to FIG. In FIG. 4A, 1 is a reaction tube made of quartz or the like, 2 is a susceptor made of carbon or the like for holding a growth substrate, 3 is a rotating shaft for rotating the susceptor, 4
Is a growth substrate placed on a susceptor, and a semiconductor crystal film grows on its surface. 5 is a heater made of carbon or the like for heating the susceptor, and 6 is a support base for the heater. In this example, the heater 5 heats the susceptor 2 on which the growth substrate 4 is placed to 500 to 700 ° C., and the rotating shaft 3 rotates the susceptor 2 to 600 to 12 ° C.
A semiconductor thin film having a film thickness of several μm or less is formed on the substrate to be grown 4 by utilizing thermal decomposition of the source gas 7 while rotating at 00 rpm. As shown in FIG. 4 is placed almost horizontally in a groove formed on the susceptor 2. For example, the substrate has a diameter of 50 mm, the reactor pressure is, for example, 76 torr, and the gas flow rate is about 30 L / mi.
n, the gas flow rate near the substrate surface is 12 cm / sec. In this example, four growth substrates are processed at the same time. Needless to say, this is a semiconductor vapor phase growth apparatus intended for mass production. Therefore, the crystal film thickness in the plane of the growth substrate, the composition in the crystal, etc. Are required to be uniform, and the characteristics such as the film thickness and composition of the semiconductor thin films formed on the four growth substrates to be processed at the same time must be the same. The rotation of the susceptor is performed to achieve these uniformity, and the 600 to 12
It is known that the use efficiency of the raw material gas is increased by the rotation speed of 00 rpm as compared with the case where the rotation speed is low. In order to achieve uniformity, attempts have been made to adjust the manufacturing conditions such as the number of revolutions of the susceptor, the pressure inside the reaction furnace, the gas supply amount to the reaction furnace, and the heating temperature.

[0003]

However, the so-called MOCVD (Metal Organic Chemical Vapor Deposition) method, in which hydrogen is used as a source gas, and an organic metal gas such as TMIn (trimethylindium) and a hydride gas such as PH ₃ are contained in the hydrogen gas and supplied. growth)
In the method, when the above-mentioned reaction furnace is adopted, the characteristics of the semiconductor thin film formed on the growth substrate are distributed. Taking the film thickness as an example, as shown in FIG. 4C, the growth film thickness tends to become thinner from the rotation center of the susceptor toward the outer peripheral direction of the susceptor. Even if the manufacturing conditions and the number of rotations are adjusted, for example, the diameter is 50 mm.
The film thickness distribution on the substrate to be grown is not improved to ± 5% or less. In addition to the film thickness, for example, the crystal composition and the distribution of impurities in the crystal also show the distribution from the rotation center of the susceptor toward the outer peripheral direction of the susceptor like the film thickness, and it is necessary to further improve the uniformity for mass production. . An object of the present invention is to solve the above problems, improve the uniformity of a crystal film, and provide a semiconductor vapor phase vapor phase apparatus suitable for mass production.

[0004]

The present invention has been made in view of the above circumstances, and the object of the present invention can be achieved by the following semiconductor vapor phase growth apparatus. That is, a plurality of substrates to be grown are held substantially horizontally in a reaction furnace, and at least the plurality of substrates are kept at 300 rpm or more about 200 rpm around a rotation axis.
In a semiconductor vapor phase growth apparatus having a mechanism for revolving at a speed of 0 rpm or less, a rotating susceptor for holding the growth substrate is a donut-shaped susceptor, and a disk is rotatable in a central hole of the donut-shaped susceptor. This can be achieved by a semiconductor vapor phase growth apparatus characterized by being provided. The rotation speed of the rotating disk of this semiconductor vapor phase growth apparatus is preferably lower than the rotation speed of the donut-shaped susceptor.

[0005]

The present invention will be described below with reference to the illustrated embodiments. FIG. 1 is a sectional view of an embodiment of the semiconductor vapor phase growth apparatus of the present invention. In the figure, 10 is a susceptor having a donut-shaped planar shape rotated by a rotating shaft 12, 11 is provided inside a central hole of the donut-shaped susceptor, and the rotating shaft 1
A rotating disk rotated by 3; 14 a heater for heating the susceptor 10; 15 a support base for the heater;
Is an electrode rod for supplying electric power to the heater 14. Reference numeral 17 is a terminal for introducing a current from outside the reaction furnace to the electrode rod 16 inside the reaction furnace. Reference numeral 19 is a first rotary motor that rotates the rotary shaft 12 with the belt 20, and 21 is a second rotary motor that rotates the rotary shaft 13 with the belt 22. Further, reference numeral 18 denotes a rotation introducing machine that supports the rotating shafts 12 and 13 while keeping the inside of the reaction chamber airtight. In this embodiment, a so-called magnetic seal type rotation introducing machine using magnetic fluid is adopted. 24 is an exhaust port. As in FIG. 4, 1 is a reaction tube, and 4 is a growth substrate.

FIG. 2 shows the MOCV using the reaction furnace of FIG.
It is an example of studying the InP film thickness distribution when an InP thin film is formed on an InP substrate by using the D method. The rotation speed of the donut-shaped susceptor 10 is fixed at 1000 rpm, and the rotation speed of the rotating disk 11 is changed. It is when changing. The rotation speed of the rotating disk 11 is the same as that of the donut-shaped susceptor.
At 000 rpm, as in FIG. 4 (c), the film thickness on the substrate surface tends to decrease in the circumferential direction of the susceptor. On the other hand, when the rotating disk is set at 0 rpm, it is almost uniform, but conversely. There was a tendency for the film thickness to increase slightly in the circumferential direction of the susceptor. By setting the rotating disk to 400 rpm, a uniform film thickness distribution as shown in FIG. 2 was obtained. The rotating disc 11 rotates in the donut-shaped susceptor 10.
It is preferably the same as that of. Further, in the present invention, making the rotation speed of the rotating disk 11 slower than that of the donut-shaped susceptor 10 includes the case where the rotation speed is 0 as the lower limit.

The action of such a rotating disk 11 is considered as follows. That is, in the conventional structure, since the raw material gas is concentrated in the central portion of the susceptor due to the rotation of the susceptor, the raw material gas concentration becomes high near the central portion of the susceptor, and the film thickness becomes relatively thinner in the peripheral portion of the susceptor than near the central portion of the susceptor. On the other hand, in the present invention, by rotating the rotating disc in the central portion at a relatively low speed, the concentration of the gas flow seen in the conventional structure is suppressed, and the uniformity of the film is improved by adjusting the rotating speed of the rotating disc. improves. As described above, the rotation speed of the rotating disk in the present invention is preferably lower than the rotation speed of the susceptor, and the rotation speed can be set to an optimum value depending on the reactor structure and crystal growth conditions. Depending on the conditions, the rotational speed may be 0 as described above.

FIG. 3 shows another embodiment of the present invention. In the present embodiment, unlike the embodiment shown in FIG. 1, the growth substrate 4 is placed on a doughnut-shaped tray 23, and the tray 23 is placed on a toroidal susceptor 10 and rotated. By adopting the tray, it becomes easy to replace the wafers on the susceptor, and it becomes possible to adopt the automatic transfer method using the preliminary chamber. The use of trays does not impair the basic effects of the present invention.
3, the same reference numerals as those in FIG. 1 indicate the same parts as those in FIG.

It is needless to say that the present invention is not limited to the above-mentioned embodiments and various modifications can be made. In the embodiment, TMIn is used as the crystal growth method,
The MOCVD method using PH ₃ has been described as an example.
The raw material is not limited to this, and TEGa (triethylgallium), AsH ₃ (arsine), TBP (tertiary butylphosphine), etc. can be used.
The present invention is effective for uniformly producing various crystal materials such as As (gallium / arsenic) and InGaAsP (indium / gallium / arsenic / phosphorus). Although the film thickness distribution has been described in the embodiment, the concentration of the raw material gas is suppressed and the distribution of the raw material gas concentration is adjusted to make the composition distribution of the constituent elements in the crystal and the impurity concentration distribution uniform. It goes without saying that you can do it. Further, although four growth substrates are illustrated in the embodiments of the present invention, the present invention is intended for handling a plurality of growth substrates, and the number is not limited to four, Also, the substrate need not be circular as shown. In addition, the present invention does not limit the material etc. of the parts used for manufacturing the reactor,
For example, the reaction tube is not limited to the quartz tube described in the embodiment, and there is no problem if it is made of other material such as stainless steel.

[0010]

As described above, according to the present invention, it becomes possible to form a crystal thin film having a good uniformity of film thickness, quality, etc. on a plurality of substrates to be grown simultaneously, which directly leads to improvement in mass productivity. Therefore, the industrial benefit is extremely large.

[Brief description of drawings]

FIG. 1 is a sectional view of an embodiment of the present invention.

FIG. 2 is a diagram for explaining the relationship between the number of rotations of a rotating disk and the thickness of a crystal film obtained by adopting the device of one example of the present invention.

FIG. 3 is a sectional view showing another embodiment of the present invention.

4A is an explanatory view of an example of a conventional semiconductor vapor phase growth apparatus, FIG. 4B is a cross-sectional view of a susceptor of the apparatus, and FIG. 4C is formed on a substrate to be grown obtained by the apparatus. It is a figure which shows the different film thickness distribution.

[Explanation of symbols]

 1 Reaction Tube 2 Susceptor 3 Rotating Shaft 4 Growth Substrate 5 Heater 6 Supporting Stand 7 Raw Material Gas 10 Donut Susceptor 11 Rotating Disc 12 Rotating Shaft 13 Rotating Shaft 14 Heating Heater 15 Heater Supporting Stand 16 Heater Electrode 17 Current Introducing Terminal 18 Rotation Introducer 19 First Rotation Motor 20 Belt 21 Second Rotation Motor 22 Belt 23 Tray 24 Exhaust Port

Claims (2)

[Claims] 1. A plurality of substrates to be grown are held substantially horizontally in a reaction furnace, and at least the plurality of substrates are placed about a rotation axis.
In a semiconductor vapor phase growth apparatus having a mechanism for revolving at a speed of 00 rpm or more and 2000 rpm or less, a rotating susceptor for holding the growth substrate is a donut-shaped susceptor, and a disk is rotated in a central hole portion of the donut-shaped susceptor. A semiconductor vapor phase growth apparatus characterized by being provided as much as possible. 2. The semiconductor vapor phase epitaxy apparatus according to claim 1, wherein the rotation speed of the rotating disk is lower than the rotation speed of the donut-shaped susceptor.