JPH08236469A - Sic boat for heat-treating wafer - Google Patents

Abstract

PURPOSE: To absorb and relieve the internal thermal stresses which occur in an upper tabular body and lower tabular body which are respectively connected to the upper and lower end sections of the main body of a boat which supports semiconductor wafers and to prevent the destruction of a lower tabular body by thermal expansion or thermal shrinkage by respectively forming slit sections in the tabular bodies. CONSTITUTION: First and second tabular bodies 31 and 32 respectively have openings 31a and 32a which are connected to the openings as both ends of the internal space of a hollow connecting cylindrical body 33. In addition, slit sections 31b, 32b, and 33b which respectively reach the openings 31a, 32a, and internal space 33a and communicate with each other are respectively formed in the platy bodies 31 and 32 and cylindrical body 33. Therefore, the internal thermal stresses which occur in the bodies 31, 32, and 33 at the time of attaching and detaching the bodies 31, 32, and 33 to and from the core tube of a vertical heat treatment furnace can be absorbed and relieved. In addition, the destruction of a lower tabular body 30 caused by a thermal shock, namely, thermal expansion or thermal shrinkage can be prevented sufficiently.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a SiC (silicon carbide) -based boat for wafer heat treatment, and more particularly to a SiC-based boat for wafer heat treatment used for heat treatment of semiconductor wafers in a heat treatment furnace.

[0002]

2. Description of the Related Art Conventionally, this type of SiC for wafer heat treatment
In the quality boat, the wafer heat treatment boat has a furnace core tube in a vertical heat treatment furnace, in which the outer circumference comes into contact with the inner peripheral surface of the furnace core tube due to deformation caused by softening of quartz glass, which is a material thereof, and the core is particularly rotated. It has been proposed to prevent an accident that damages the inner peripheral surface of the tube or an accident that a semiconductor wafer placed in the lateral direction falls, and specifically, supports the semiconductor wafer as shown in FIG. Are formed to extend in the vertical direction with respect to the inner peripheral surface of the substantially semi-cylindrical side wall, and the bottom end and the top end of the boat body 20 'made of carbon silicon are The lower plate-shaped body 30 'and the upper plate-shaped body 40' are formed by an appropriate means such as joining or fitting.
Had a linked structure.

[0003]

However, in the conventional SiC heat treatment boat for wafer heat treatment shown in FIG. 4, the length of the furnace core tube of the vertical heat treatment furnace is short, and the furnace is generally made of quartz glass having large radiation heat. Due to the fact that the core tube was created, the temperature gradient in the upper part and the lower part was large, so that the boat main body 20 ', the lower plate-shaped body 30', and the lower plate-shaped body 30 'during insertion and removal from the lower opening. There is a drawback that internal thermal stress is accumulated in the upper plate-shaped body 40 '(particularly the lower plate-shaped body 30') and is destroyed in a relatively short period of time due to thermal shock, that is, thermal expansion or thermal contraction.

Therefore, the present invention solves this drawback, and prevents SiC from being broken due to a large temperature gradient in the vicinity of the lower opening of the furnace core tube of a vertical heat treatment furnace.
It is intended to provide quality boats.

[0005]

SUMMARY OF THE INVENTION The present invention is a semiconductor wafer comprising an upper plate and a lower plate which are respectively connected to the upper end and the lower end of a boat body supporting a plurality of semiconductor wafers. In the SiC boat for heat treatment, the SiC boat for heat treatment of a semiconductor wafer is characterized in that the upper plate-shaped body and the lower plate-shaped body are provided with slits.

[0006]

In the SiC heat treatment boat for wafer heat treatment according to the present invention, the slit portion is provided for the upper plate member and the lower plate member connected to the upper end and the lower end of the boat body supporting the semiconductor wafer, respectively. Since it is drilled, it absorbs and relaxes internal thermal stress and prevents destruction due to thermal expansion or thermal contraction, which in turn extends the life.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, preferred embodiments of the present invention will be described with reference to the accompanying drawings.

FIG. 1 shows a SiC for heat treatment of a wafer according to the present invention.
It is a perspective view which shows the example which uses a quality boat for a vertical heat treatment furnace.

FIG. 2 is a partial perspective view of the same, and particularly shows a lower plate-shaped body.

FIG. 3 is a perspective view showing the same use state.

First, the structure of the SiC boat for wafer heat treatment of the present invention used in the vertical heat treatment furnace will be described in detail.

A SiC boat 10 for wafer heat treatment according to the present invention includes a boat body 20 made of SiC and an S boat.
A lower plate-shaped body 30 made of iC and connected to the lower end of the boat body 20 by an appropriate means such as joining or fitting, and a lower plate 30 made of SiC and joined to the upper end of the boat body 20. The upper plate member 40 is connected by an appropriate means such as fitting.

The boat body 20 is formed in a substantially semi-cylindrical shape, and has a plurality of (for example, four) ridges 21a, ... , 21d are formed extending in the vertical direction. The boat body 20 is provided between the ridges 21a, 21d.
In order to prevent the destruction of the boat body due to thermal shock, reduce the weight of the boat body 20 and reduce the heat capacity to improve the heat distribution, an appropriate number of window grooves 22a, 22c, 22c are formed on the side walls thereof.
Are formed. A plurality of wafer supporting grooves 23a, ..., 23d are bored in the ridges 21a, ..., 21d, respectively. The wafer supporting grooves 23a to 23d are formed one by one at the same height position with respect to the inner peripheral surfaces of the protrusions 21a to 21d, and are semiconductor wafers to be heat-treated (not shown). Is inserted and placed in the lateral direction.

A window 22 is provided at the bottom of the boat body 20.
The slit portion 24 communicated with any of a, 21a, and 21c (here, the window portion 22b) may be formed, so that when the vertical heat treatment furnace 50 is inserted into or taken out of the furnace core tube 52, or the furnace core thereof. The internal thermal stress generated during heating by the heater 53 in the pipe 52 can be absorbed and relaxed, and the boat body 2
The thermal shock of 0, that is, the destruction due to the thermal expansion or the thermal contraction can be prevented.

The lower plate-shaped body 30 is directly connected to the lower part of the boat body 20 by a suitable means such as adhesion or fitting, and the first plate-shaped body 31 and the SiC boat for wafer heat treatment of the present invention. A second plate-shaped body 32 for inserting and removing 10 into and from the furnace core tube 52 of the vertical heat treatment furnace 50, or mounting it on the boat mounting table 51 that supports and rotates with respect to the furnace core tube 52, and And a connecting hollow cylindrical body 33 for connecting the second plate-shaped bodies 31 and 32 to each other. The first and second plate-like bodies 31 and 32 are provided with openings 31a and 32a connected to the openings at both ends of the internal hollow 33a of the connection hollow cylinder 33, respectively. In addition, the plate-shaped bodies 31 and 32 and the connecting hollow cylindrical body 33 have openings 31a and 32a and an internal hollow 33a from the outer peripheral surface, respectively.
And the slit portions 31b, 32 that reach each other and communicate with each other.
b and 33b are bored to absorb and relax internal thermal stress generated when the vertical heat treatment furnace 50 is inserted into and taken out of the furnace core tube 52 or when the furnace core tube 52 is heated, and thermal shock of the lower plate-shaped body 30. That is, it is possible to sufficiently prevent the destruction due to the thermal expansion or the thermal contraction.

In the embodiment of FIG. 1, the upper plate 40 is not provided with openings and slits, but the present invention is not limited to this, and if desired, similar to the lower plate 30. You may form these in. This is advantageous because the upper plate 40 can be further prevented from being damaged by thermal shock, that is, thermal expansion or contraction, and the SiC boat 10 for wafer heat treatment of the present invention can be reduced in weight as a whole. .

Further, the Si for wafer heat treatment according to the present invention
The operation of the C-quality boat will be described in detail.

The wafer support groove 23a of the boat body 20,
After mounting a desired number of semiconductor wafers (not shown) to be heat-treated on the substrate 23 to 23d, the lower plate-shaped body 30 is mounted on the boat mounting table 51.

Next, the boat mounting table 51 is raised and the SiC boat 10 for wafer heat treatment of the present invention is loaded into the furnace core tube 52 of the vertical heat treatment furnace 50 through the lower opening 52a. At this time, since the slit portions 31b, 32b, 33b are formed, the lower plate-shaped body 30 is formed in the vertical heat treatment furnace 50.
Even if the furnace core tube 52 is rapidly heated due to a large temperature gradient inside the furnace core tube 52, internal thermal stress can be absorbed and relaxed, and thermal shock and eventually destruction due to thermal expansion can be avoided. Further, if the window portions 22a, 22c, and 22c and the slit portion 24 are formed on the boat main body 20, it is possible to avoid the thermal shock of the boat main body 20 and the destruction due to the thermal expansion, which is preferable. In addition, if the opening and the slit (particularly the slit) are formed in the upper plate 40, the thermal shock of the upper plate 40 and the destruction due to the thermal expansion can be prevented, which is more preferable.

Even when the semiconductor wafer is heat-treated in the furnace core tube 52, the SiC heat treatment boat 1 for wafer heat treatment of the present invention is used.
At 0, the slit portions 31b, 32b, 3
Since 3b is formed, it is possible to prevent thermal destruction of the lower plate-shaped body 30 due to a large temperature gradient at the lower end of the furnace core tube 52. Further, if the slit portion 24 is formed in the boat body 20, it is possible to prevent thermal destruction of the boat body 20 due to a large temperature gradient at the lower end portion of the furnace core tube 52, which is preferable. In addition, if the opening and the slit (particularly the slit) are formed in the upper plate 40, the thermal destruction of the upper plate 40 due to the large temperature gradient at the upper end of the furnace core tube 52 is also included. Can be prevented and is more preferable.

After the heat treatment of the semiconductor wafer inside the furnace core tube 52 of the vertical heat treatment furnace 50 is completed, the boat mounting table 51
Is lowered, and from the lower opening 52a of the furnace core tube 52 of the vertical heat treatment furnace 50, the SiC heat treatment boat 1 for wafer heat treatment of the present invention 1
Take out 0. At this time as well, the SiC boat 10 for wafer heat treatment of the present invention can absorb and relax internal thermal stress due to a large temperature gradient at the lower end of the furnace core 52, and prevent thermal destruction thereof, as in the case of insertion.

In the above example, the lower plate-like body 3
0 includes two plate-like bodies 31 and 32 and a communicating hollow cylindrical body 33, but if desired, this may be replaced by one plate-like body 3
There is no problem even if it is formed of only one.

The shape of the lower plate-shaped body 30 is annular, but if desired, at least one of the outer shape and the opening may be polygonal.

Further, the shape of the upper plate-like body 40 is a disk shape, but it may be a polygonal shape if desired, and if an opening is also formed, it may be a polygonal shape. .

In addition, although the boat main body 20 is formed in a semi-cylindrical shape, it may be formed by simply a plurality of (for example, four) rods, and a wafer supporting groove may be formed inside each of them. .

[0026]

As is clear from the above, the SiC heat treatment boat for wafer heat treatment according to the present invention has an upper plate-shaped body and a lower body connected to the upper end and the lower end of the boat body supporting the semiconductor wafer, respectively. (I) Sufficient absorption and relaxation of internal thermal stress applied by the large thermal gradient of the furnace core tube during insertion / extraction of the furnace core tube of the vertical heat treatment furnace because the slit is formed in the plate-like body. In the furnace core tube made of quartz glass, which has the effect of (ii) preventing thermal destruction and having a long life, and (iii) having a large radiant heat and a large thermal effect on the boat. Has the effect of withstanding long-term use at

[Brief description of drawings]

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

FIG. 2 is a partial perspective view of the same.

FIG. 3 is a perspective view showing the same usage state.

FIG. 4 is a perspective view showing a conventional example.

[Explanation of symbols]

 10 Wafer Heat Treatment SiC Boat 20 Boat Main Body 21a, ~, 21d Projection 22a, ~, 22c Window 23a, ~, 23d Wafer Support Groove 24 Slit 30 Lower Plate 31, 31 Plate 31a, 32a Openings 31b, 32b, 33b Slits 33 Connection hollow cylinder 33a Inner hollow 40 Upper plate 50 Vertical heat treatment furnace 51 Boat mounting table 52 Furnace core tube 52a Lower opening

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Shigeru Abe 378, Oguni Town, Oguni Town, Nishiokitama District, Yamagata Prefecture Inside the Oguni Factory of Toshiba Ceramics Co., Ltd.

Claims (1)

[Claims] 1. A SiC wafer boat for heat treating semiconductor wafers, comprising: an upper plate-shaped body and a lower plate-shaped body connected to an upper end portion and a lower end portion of a boat body supporting a plurality of semiconductor wafers, respectively. A SiC boat for heat treatment of a semiconductor wafer, characterized in that slit portions are formed in the upper plate-shaped member and the lower plate-shaped member.