JPS6058613A - Epitaxial apparatus - Google Patents

Abstract

PURPOSE:To eliminate protrusion defect of wafer by using susceptor disk at the reaction part with a coating of silicon carbide on a graphite material and forming a susceptor holding jig or susceptor holding jig and pedestal with silicon carbide. CONSTITUTION:A reaction gas entrance 2 is provided to a quartz bell-jar 1 and a high frequency induction coil 3 is provided within a quartz cover 4 for epitaxial growth on a silicon wafer 5. A susceptor 6 is formed by a disk type graphite material coated with silicon carbide and circular recessions 12 are arranged with the specified interval for define the positions of wafer 5. A cylindrical pedestal 7 is made of quartz and supports the suscepter 6 at the center and rotates it in the horizontal plane. A susceptor holding jig 10 is made of silicon carbide, it is engaged with the upper part of pedestal 7, and supports and fixed the suscepter at the center. Thereby, the Si powder is no longer adhered to the epitaxial surface of wafer and protrusion defect of wafer can be eliminated.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to a technology that is effective when applied to an epitaxial device, particularly to a reaction section structure thereof.

[Background technology]

Epitaxial equipment for epitaxial growth, which is essential in the fabrication of semiconductor devices, is S
A semiconductor substrate such as i (silicon) is heated to a desired temperature (1150 t:'
The device is equipped with a heating power supply section that heats the substrate to a temperature of ±5 C), a gas supply section that controls and supplies the flow rate and concentration of the source gas, and a reaction section that reacts the source gas and causes epitaxial growth on the substrate.

The typical structure of the above reaction part is '-C (11 horizontal, (
There are 2) vertical structure and (3) barrel structure. Of these, vertical structure is designed to supply gas while horizontally rotating the susceptor as shown in Figure 1, and the epitaxial growth layer is grown on the same circumference. It is widely used because it has a uniform thickness and resistivity, and by making the gas flow uniform from the center of one rotation, it is possible to obtain an epitaxial layer that is uniform over the entire surface and has high precision. In the same figure.

1 is a quartz bell jar, 2 is a reaction gas inlet, 3 is an RF coil (high frequency induction coil), 4 is a quartz cover, and 5 is a silicon wafer.

The vertical reaction section includes disk-shaped susceptors 6 and 1. A vertical tubular pedestal 7 that horizontally supports this susceptor 6 at its center.
, a susceptor holding jig 8 for preventing vibration of the susceptor, and a rotation mechanism (not shown) for rotating the susceptor.
and a gas ejection nozzle 9 that ejects the reactive gas introduced through the pedestal from above onto the surface of the semiconductor substrate 5 on the susceptor 6.
The material used is black N(C), which is a highly heat-resistant and conductive material, coated with silicon carbide (5 inches).

The pedestal 7 and the susceptor holding jig 8 were made of quartz (Sin), which is a highly heat-resistant material.

By the way, in epitaxial growth, for example, according to the thermal decomposition method, hydrogen is supplied and convection is carried out inside the bell jar.1. C is heated to decompose it into Sl and H3, and this Sl is deposited on Pheno 1. At this time, 8
1 not only deposits on the wafer, but also adheres to the pedestal made of quartz and the susceptor holding jig, which are close to the reaction gas jet nozzle. It is clear from the applicant that some of the adhered St then peels off for some reason and is secondarily attached to the wafer surface, causing protrusions on the wafer. It was said that

Such protrusion defects cause defects in semiconductor crystals, leading to deterioration in the characteristics of semiconductor products.

In particular, this phenomenon occurs particularly in epitaxial growth using S iHa, 81) (t CJ t as a reactive gas).

[Purpose of the invention]

The present invention solves the above problems.

The purpose is to provide an improved epitaxial device that can eliminate protrusion defects during epitaxial growth and improve the reliability of semiconductor products.

The above-mentioned pressure and other objects and novel features of the present invention are as follows:
It will become clear from the description of this specification and the accompanying drawings.

[Summary of the invention]

A brief summary of typical inventions disclosed in this application is as follows.

That is, in a reaction section of an epitaxial device having a susceptor, a pedestal, and a susceptor holding jig, the susceptor is made of graphite coated with silicon carbide, and the susceptor holding jig or the susceptor holding jig and the pedestal are used. By using silicon carbide, the wafer protrusion defects during epitaxial growth are prevented, thereby achieving the above object.

〔Example〕

FIG. 2 is an embodiment of the present invention, and shows a vertical cross-sectional perspective view of a vertical reaction section.

6 is a susceptor made of silicon carbide (SiC) on a disc-shaped graphite material.
It is coated with circular recesses 12 arranged at predetermined intervals on the upper surface for defining the wafer position.

7 is a cylindrical pedestal made of quartz that supports the susceptor 6 at its center and rotates on a horizontal plane.

A susceptor holding jig 10 is made of silicon carbide and is fitted onto the upper part of the pedestal 7 so as to press and fix the susceptor at the center.

FIG. 3 is a front cross-sectional perspective view of a vertical reaction section according to another embodiment of the present invention. In this embodiment, the pedestal 11 as well as the susceptor holding jig 10 are made of silicon carbide.

[Effects] According to the present invention described in the examples above, the following effects can be obtained.

The quartz (5ift) used as the material for the susceptor holding jig and pedestal has a low Il electric rate, so it is difficult to be heated by high-frequency heating, and even if St precipitates and adheres, some of it peels off and becomes Si powder, which is transferred to the wafer. It adhered to the surface of the epitaxial layer and caused protrusion defects. However, silicon carbide (SiC) used for the susceptor holding jig and pedestal in the present invention has a large dielectric constant compared to quartz and is easily heated, so Si tends to adhere thereto.

There was no possibility that St powder would form and adhere to the surface of the epitaxial layer of the wafer, and no protrusion defects would occur.

As described in Embodiment 5 of the present invention, in the vertical reaction section, the above effect can be obtained by forming at least the susceptor holding jig close to the wafer from silicon carbide. The effect will be even more remarkable if it is formed with.

Although the invention made by the present inventor has been specifically described above based on examples, it goes without saying that the present invention is not limited to the above-mentioned examples, and can be modified in various ways without departing from the gist thereof. Nor.

[Application field]

In the above description, the present invention was mainly applied to epitaxial device technology, which is the background field of application of the invention, but the present invention is not limited thereto.

The present invention can be applied to an epitaxial device having a vertical reaction section. In particular, it is most effective when applied to epitaxial devices for manufacturing high-speed bipolar memories.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing the overall structure of an epitaxial device having a vertical reaction section. FIG. 2 is a perspective sectional view of a main part of a reaction section of an epitaxial device, which is an embodiment of the present invention. FIG. 3 is another embodiment of the present invention, and is a perspective sectional view of a main part of a reaction section of an epitaxial device. 1...Quartz bell jar, 2...Reaction gas inlet, 3...
・RF coil, 4301 quartz cover, 5-1. Silicon wafer, 6... graphite susceptor, 7... pedestal (SiOy). 8... Susceptor holding jig (SiOz) -9... Gas jet nozzle, 10... Susceptor holding jig (SiC),
11... Pedestal (SiC), 12... Recess. Figure 1: 5 no H4 z Figure 2 Figure 3/θ

Claims (1)

[Claims] 1. A heating power supply section for heating the semiconductor substrate to a desired temperature on the susceptor, a gas supply section for controlling and supplying the flow rate and concentration of the raw material gas, and a reaction section for reacting the raw material gas for epitaxial growth on the substrate. an epitaxial device comprising: a disk-shaped susceptor; a vertical tubular pedestal that horizontally supports the susceptor at its center; a susceptor holding jig; and a rotation device that rotates the susceptor. It has a mechanism and a gas ejection nozzle that ejects the gas introduced through the pedestal from above, and the susceptor is made of graphite material coated with silicon carbide, and the susceptor holding jig or the susceptor holding jig and An epitaxial device characterized in that the pedestal is made of silicon carbide.