JPS60153116A - Vertical diffusion furnace type vapor growth apparatus - Google Patents

Abstract

PURPOSE:To increase the number of processed wafers and to facilitate the automatic handling, by carrying wafers parallel on a wafer supporting member having a plural of tiers whose axial line coincides with that of a cylindrical reacting container and by providing with a uniformly-heating tube consisting carbon or silicon carbide arranged concentrically. CONSTITUTION:Wafers 52 are carried on tiers (a) of a wafer supporting member 54. While reacting gas is supplied from a reacting gas supply nozzle 53 and purge gas such as hydrogen gas is supplied from a nozzle 60, a uniformly-heating tube 58 is heated by infrared ray lamps 55 to cause the wafers 52 to epitaxial- grow. Since the space in the uniformly-heating tube 58 becomes practically a uniform-temperature atmosphere by its heating, both the top and bottom surfaces of the wafers 52 is more uniformly heated. Accordingly, thick-irregularity of epitaxial films owing to irregularity of the temperature distribution over the wafers 52 hardly results. The wafers 52 are took in and out, with carried on carrying jigs 65 which are to be set in the wafer supporting member 64.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a vapor phase growth apparatus, and particularly to a vertical diffusion furnace type vapor phase growth apparatus for manufacturing semiconductor devices such as silicon.

[Prior art]

Conventionally used devices for epitaxial thin film vapor phase growth of semiconductor materials such as silicon can be broadly classified into vertical, horizontal, and cylindrical types based on their shapes. In any of these types of devices, for epitaxial growth of silicon, etc., the entire back surface is placed in close contact with a carbon susceptor plate that is placed in a quartz reaction vessel and heated to approximately 1200°C by a heating device. A silicon crystal thin film is grown on the wafer by placing a wafer on the wafer and flowing a reactive gas onto its surface.
It's a small thing. In addition, as the above-mentioned heating device, induction heating using high frequency or lamp heating method using infrared lamp etc. is usually used, and regardless of which heating device is used, there is no space outside the reaction vessel, such as By using a forced cooling method that uses pipes and the like to blow cooling gas, it is important to connect the reaction chamber with other processes such as photolithography. Problems have arisen regarding automatic handling. In the three types of vapor phase growth apparatus mentioned above, the wafer is placed closely on the susceptor, which is the heating element, so some kind of substance must be brought into contact with the wafer surface when loading and unloading the wafer. This causes contamination and reduced yield.

Hereinafter, based on the accompanying drawings, the outline of the three types of vapor phase growth apparatuses mentioned above will be explained in relation to the problems mentioned above.

FIG. 1 shows a conventional vertical vapor phase growth apparatus, which is usually placed airtight on a base 10 using a quartz verge to define a reaction chamber 16, and can be rotated into the reaction chamber 16. The wafer 12 is placed on a susceptor 14 provided on the susceptor 14 with its entire back surface in close contact, and a reaction gas is blown out from the nozzle 13 and heated by, for example, a high-frequency induction heating coil 15 provided at the bottom of the susceptor 14 to form an epitaxial layer on the wafer 12. It is designed to perform vapor phase growth. Automatic handling of this vertical type must be performed by suctioning the upper surface of the wafer 12, which causes the problems described above, and furthermore, the batch processing of wafers is difficult due to the large floor area occupied by the apparatus itself. Since the number of wafers is small and the arrangement is relatively complicated, automatic handling of the wafers is difficult.

FIG. 2 shows a conventional general horizontal vapor phase growth apparatus, in which a susceptor 24 is provided in the longitudinal direction of a reaction chamber 26 formed inside a reaction tube 21 made of quartz. The wafer 22 is placed with its entire back side in close contact with each other,
A reaction gas is flowed from one side in the longitudinal direction, and heated by a high-frequency wave 710 installed at the outer part of the reaction tube 21.
Epitaxial vapor phase growth is performed on a wafer 22. This horizontal type also has problems with automatic handling because the entire back surface of the wafer 22 is brought into close contact with the susceptor 24, resulting in a decrease in yield.Furthermore, the number of wafers to be processed in batches is small considering the floor space occupied, and especially in reaction This has the disadvantage that a space is required to draw the susceptor 24 laterally from inside the tube 21, and the actual occupied floor area becomes even larger.

FIG. 3 shows a conventional general cylinder type vapor phase growth apparatus. In this apparatus, a polyhedral susceptor 34 is suspended rotatably in the left and right directions in a reaction chamber 36 in a reaction tube 31 made of quartz. The wafer 32 is placed on the susceptor 34 so that its entire back surface is in close contact with the wafer 32 . An infrared lamp unit 35 is provided outside the reaction tube 31 as a heat source, and a reaction gas is supplied from a nozzle 33 to perform epitaxial vapor phase growth on the wafer 32. In addition, by providing a reflector plate 37f behind the infrared lamp 35, the reflected energy of the lamp is also effectively utilized.

Regarding this type of apparatus, when considering the same problems as the previous two types, the number of wafers processed increases compared to the vertical and horizontal types described above, but the number of wafers placed on the susceptor 34 increases. 32 is complicated and requires precision, and poses problems in terms of automatic handling.

FIG. 4 shows a conventionally known low pressure CVD apparatus similar in shape to a conventional horizontal vapor phase growth apparatus. A large number of wafers 42 are vertically disposed on the wafer support plate 48 . This kind of U
In the VD apparatus, since the wafers 42 are arranged vertically, the number of wafers processed per batch increases, but a space is required to pull out the wafer support plate 48 horizontally from inside the reaction chamber 46, which reduces the occupied floor space. In addition to increasing
Other processes before and after the vapor phase growth process are often carried out with the wafer 42 in a substantially horizontal position, which has the disadvantage that automatic handling from the vertical direction to the horizontal direction becomes complicated. In addition, in this (1VDi setting), the reaction tube 4 is heated by the resistance heater 45 without using a susceptor.
1 becomes a hot wall type, which is undesirable because flakes adhere to the tube wall and cause foreign matter generation.

As mentioned above, conventional vapor phase growth equipment and CvD
There have been various problems with the equipment, such as automatic handling causing contamination and a reduction in yield, and automatic handling requiring equipment that is complex and difficult to control.

[Purpose of the invention]

The purpose of the present invention is to provide a vertical diffusion furnace type vapor phase growth apparatus that eliminates the drawbacks of the conventional apparatus mentioned above, increases the total number of wafers that can be processed even when the diameter of wafers increases, and facilitates automatic handling of wafers. Our goal is to provide the following.

[Structure of the invention]

A vertical diffusion furnace type vapor phase growth apparatus according to the present invention provided to achieve the above-mentioned object is a cylindrical quartz reactor having a reaction gas supply nozzle at the upper end and a gas exhaust port at the lower end. This is a type in which a wafer is set in a container, a heating heat source is placed around the outer periphery of the reaction container, and an epitaxial thin film is vapor-phase grown on the wafer using a reaction gas. A soaking tube made of carbon or silicon carbide placed in parallel in multiple stages on a support member having an axis that substantially coincides with the axis of the reaction vessel, and arranged concentrically with a gap from the inner wall of the reaction tube. It is characterized by having the following.

〔Example〕

The present invention will be explained in more detail below based on the embodiments shown in the accompanying drawings.

FIG. 5 shows a vertical diffusion furnace type vapor phase growth apparatus according to the present invention, and in particular, the structure is basically an application of the cylinder type vapor growth apparatus shown in FIG. 3 and the CvD apparatus shown in FIG. It is thought that this was done. That is, in a reaction chamber 56 in a cylinder-type reaction vessel (hereinafter referred to as a reaction tube) 51 usually made of quartz, there are a number of step portions af for placing a plurality of wenos 52 at equal intervals in a horizontal step shape. A supporting member 54 made of quartz is suspended vertically so that its axis substantially coincides with the center line of the reaction tube 51 and is rotatable about the axis.

An infrared lamp 55 as a heat source is installed on the outer periphery of the reaction tube 51.
is provided. On the other hand, inside the reaction tube 51, a material that can efficiently absorb lamp light, such as carbon or silicon carbide, is formed at a position slightly away from the inner wall surface of the reaction tube 51 so as to surround the wafer support member 54. A soaking tube 58 is provided. The length of the soaking tube 58 in the vertical direction preferably matches or slightly exceeds the length of the wafer support member 54 in the vertical direction.
A plurality of reaction gas supply nozzles 53 are provided at the top of the
On the other hand, an exhaust port 59 is provided at the lower end of the reaction tube 51 . Further, at the upper part of the reaction tube 51, a bar of hydrogen, nitrogen, argon, etc. is provided between the inner wall of the reaction tube 51 and the soaking tube 58.
Deer, a plurality of nozzles 60 that flow X are provided, and a reaction notice 51
In addition to cooling the inner wall surface of the reaction tube 51, the reactant gas is prevented from entering the reaction tube 51 and depositing the reactant on the inner wall surface of the reaction tube 51.

Note that this device is the same as the conventional device in that a reflector plate 57 is provided behind the infrared lamp 55 to fully utilize the reflected energy.

Next, the operation of this device will be explained. A sea urchin .
5, the soaking tube 58 is heated to perform epitaxial growth. Since this device is only supported by the end of the weno 52 by the weno support member 54 made entirely of quartz,
Rather than heating the wafer 52' through the susceptor as in the conventional apparatus shown in FIGS. 1 to 3, the soaking tube 58 is heated by the infrared lamp 55 as described above. The heating of this soaking tube 5 creates a substantially uniform temperature atmosphere in the interior space, so that both the front and back surfaces of the sea urchins 52 are heated more uniformly. Therefore, unevenness in the thickness of the epitaxial film due to unevenness in the temperature distribution of the wafer 52 hardly occurs.

In addition, in the case shown in Fig. 5, the Weno-52 is arranged in a direction almost perpendicular to the flow of the reaction gas from the nozzle 53, so the gas flow must be in a turbulent or molecular flow state to have a uniform concentration. However, in the embodiment of the present invention, in this respect, the (v1) device shown in FIG. This makes it possible to make the gas concentration uniform.Also, by greatly lowering the pressure, precise control of the thickness of the grown film becomes easy.

FIG. 6 shows a modified embodiment of the weno support in the present invention, in which the weno support is made of silicon carbide or carbon to prevent rapid heating and cooling of the weno 52 due to the ON and OF:l'' of the infrared rungs 55. The wafer 52 is placed through a mounting jig 65 such as a plate.
17 by attaching it to the wafer support member 64. In this case, the Ueno 52 is carried in and out together with the mounting jig A, 65. Also, as shown in FIG. It is also possible to improve the flow of reaction gas inside the reaction tube.

〔Effect of the invention〕

As described above, according to the present invention, the entire surface of the wafer can be heated more uniformly to achieve good epitaxial growth, and the number of wafers that can be processed at once can be dramatically increased, and the wafers are placed approximately horizontally. Him and the back side 111
1e Since it is possible to carry in and out while supporting, automatic no-undling is facilitated, and yield reductions due to damage to the epitaxial film can be reduced.

[Brief explanation of drawings]

Figures 1 to 3 are schematic sectional views of conventional vertical, horizontal, and cylinder type vapor phase growth apparatuses, Figure 4 is a schematic sectional view of a conventional Narita CVI) apparatus, and Figure 5 is a vertical type according to the present invention. The diffusion furnace is a longitudinal sectional view of the vapor phase growth apparatus, and FIGS. 6 and 7 are
FIG. 3 is a drawing showing different modified embodiments of the support part shown in FIG. 51... Reaction container, 52... S'., 53...
・Reaction gas supply nozzle, 54.64.74... Weno support member, 55...
Heat source (infrared lamp), 56... Reaction chamber, 57...
・Reflector plate, 58... Soaking tube, 59... Exhaust port,
60... Nozzle (purge gas), 65... Mounting jig. Applicant: Toshiba Machine Co., Ltd. Sai 1 Leap 1゜ Figure 3, Entrance 2

Claims (1)

[Claims] 1. In a vapor phase growth apparatus for vapor phase growth of a pitaxial thin film in a cylindrical quartz reaction chamber having a reaction gas supply nozzle at the upper end and a gas exhaust port at the lower end, All of the wafers are placed in parallel in multiple stages on a wafer support member having an axis that substantially coincides with the axis of the cylindrical reaction vessel, and carbon or carbonized wafers are placed concentrically with a gap from the inner wall of the reaction tube. Vertical diffusion furnace type vapor phase growth apparatus 2 characterized by being provided with a soaking tube made of silicon
The vapor phase growth apparatus according to claim 1, wherein the wafers are placed horizontally while maintaining parallel states. 3. The vapor phase growth apparatus according to claim 1, wherein each of the wafers is placed at an angle with respect to the axis of the wafer support member while maintaining a parallel state. 4. The vapor phase growth apparatus according to claim 1, wherein a purge gas is made to flow through a gap between the soaking tube and the inner wall of the reaction vessel. Vapor phase growth equipment. The vapor phase growth apparatus according to claim 6, which is arranged to be mounted flatly, but which is arranged to be mounted at an angle with respect to the axis of the wafer support member.