JP3567129B2 - Heat treatment furnace - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a heat treatment furnace used for forming an oxide film on a surface of a semiconductor wafer or performing a process such as diffusion.
[0002]
[Prior art]
When a silicon oxide film (SiO ₂ ) or the like is formed on the surface of a semiconductor wafer, for example, a vertical heat treatment furnace shown in FIG. 2 is used. Referring to FIG. 1, this conventional heat treatment furnace includes a cylindrical heater 50, and a soaking tube 51 and a process tube 52 which are sequentially and concentrically arranged at a predetermined interval inside the heater 50. The heater 50 is covered with a heat insulating wall 50a, and the heat insulating wall 50a is supported by a heater base 53.
[0003]
The heat equalizing tube 51 is formed by, for example, sintering silicon carbide (SiC) in accordance with the outer shape of the process tube 52, and uniformly transmits radiant heat from the heater 50 to the process tube 52. . As shown in the drawing, the heat equalizing tube 51 has an open lower end, is placed on a heat equalizing tube support 54, and is fixed to the heater base 53 via a tube support 55.
The process tube 52 is provided with a flange 52a at the lower part of the outer periphery thereof. A tube support 55 is interposed between the upper surface of the flange 52a and the heat equalizing tube support 54, and the flange 52a is formed by the tube support 55 and the skirt 56. Is pinched.
[0004]
Further, in this heat treatment furnace, a furnace port door 57 configured to be openable and closable is provided below the process tube 51, and the semiconductor wafer W is loaded between the inside of the process tube 51 and the load chamber 58. An elevating device 59 for taking out is provided.
As described above, in this conventional heat treatment furnace, the soaking tube 51 serving as a soaking means is disposed between the heater 50 and the process tube 52 so that the processing temperature in the process tube 52 is made uniform and the above-described silicon oxide A film or the like is formed on the surface of the semiconductor wafer W.
[0005]
[Problems to be solved by the invention]
However, in the above-described conventional heat treatment furnace, since the heat equalizing pipe 51 and the process tube 52 are sequentially arranged at predetermined intervals inside the heater 50, it is difficult to reduce the inner diameter of the heater 50. There is a problem that it is difficult to reduce the size. Further, as shown in FIG. 2, since the heat equalizing tube support 54 and the tube support 55 are provided at the furnace port to support the heat equalizing tube 51 and the process tube 52, the furnace port structure is complicated.
In addition, the heat equalizing tube 51 is expensive and is liable to be damaged such as a crack, so that it is required to pay close attention to its handling.
[0006]
In view of the conventional problems as described above, the present invention provides a heat treatment furnace that can easily reduce the size and simplify the structure of the heat treatment furnace and that can be easily handled at low cost. Aim.
[0007]
[Means for Solving the Problems]
The heat treatment furnace of the present invention is provided with a tubular heater, a process tube disposed inside the heater, and a heater provided between the heater and the process tube, and radiating heat from the heater uniformly to the process tube. A heat treatment furnace provided with a soaking means for conducting,
The heat equalizing means is constituted by a fibrous heat equalizing member covered on an outer surface of the process tube (claim 1).
[0008]
In the heat treatment furnace configured as described above, the heat equalizing means provided between the heater and the process tube is configured by the fibrous heat equalizing member covered on the outer surface of the process tube, and thus the process tube and The structure of the heat treatment furnace can be easily reduced in size by reducing the distance between the heater and the heater. Further, since the heat equalizing member can be supported by the process tube, the structure of the heat treatment furnace can be simplified.
[0009]
In the heat treatment furnace as described above (Claim 1), the heat equalizing member may be formed of a continuous fiber molded into a predetermined shape (Claim 2). In this case, the heat equalizing member can be easily covered on the outer surface of the process tube.
[0010]
In the heat treatment furnace as described above (claim 1 or 2), the heat equalizing member is preferably formed in a bag shape (claim 3). In this case, the work of attaching the heat equalizing member to the process tube can be easily performed.
[0011]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, preferred embodiments of the heat treatment furnace of the present invention will be described with reference to the drawings.
FIG. 1 is a schematic sectional view showing a heat treatment furnace according to one embodiment of the present invention. In FIG. 1, in the heat treatment furnace of the present embodiment, a cylindrical heater 1, a process tube 2 having an open lower end, and a heat equalizing member 3 as a heat equalizing means provided between the heater 1 and the process tube 2 are provided. Have. The heater 1 is covered with a heat insulating wall 1a, and the heat insulating wall 1a is supported by a heater base 4.
[0012]
The process tube 2 constitutes a vertical furnace body, and a furnace port door 6 is attached to the lower end opening so as to be openable and closable. In the process tube 2, a boat 7 on which a semiconductor wafer W as an object to be processed is mounted so as to be able to move up and down.
Further, the process tube 2 has a flange 2a protruding from a lower portion of the outer periphery, and the flange 2a is sandwiched between the heater base 4 and the skirt 5 via a cushion material 8 along the upper and lower surfaces thereof, It is supported at a predetermined position. The heater base 4 and the skirt 5 are formed of an annular body having a hollow structure, and cooling water is circulated and supplied inside.
[0013]
The heat equalizing member 3 is made of a fibrous material having a high thermal conductivity, for example, continuous fibers of silicon carbide (for example, Nicalon (Nippon Carbon Co., Ltd., registered trademark)), and the outer surface of the process tube 2. The outer surface is covered by a single or multiple direct winding. Since the heat equalizing member 3 uniformly transmits the radiant heat from the heater 1 to the process tube 2, the processing temperature in the process tube 2 is made uniform so that a silicon oxide film or the like is formed on the surface of the semiconductor wafer W. Processing such as film formation processing and diffusion can be performed with high accuracy.
In addition to the above description, as the heat equalizing member 3, for example, a material obtained by cutting a continuous fiber of the silicon carbide woven into a sheet shape can be used. Alternatively, a discontinuous silicon carbide fiber having a short to medium fiber length may be formed into a predetermined shape by, for example, a known vacuum forming method. By forming the heat equalizing member 3 using the fiber molded into such a predetermined shape, the heat equalizing member 3 can be easily covered on the outer surface of the process tube 2.
[0014]
In the heat treatment furnace configured as described above, since the heat equalizing means is constituted by the fibrous heat equalizing member 3 covered on the outer surface of the process tube 2, the above-described conventional heat equalizing tube is used. Compared with the heat treatment furnace, the distance between the process tube 2 and the heater 1 can be reduced, and the structure of the heat treatment furnace can be easily reduced in size. Further, since the distance between the process tube 2 and the heater 1 can be reduced in this manner, radiant heat from the heater 1 can be efficiently transmitted to the inside of the process tube 2, and power consumption in the heater 1 can be reduced. Can be.
Further, since the heat equalizing member 3 (heat equalizing means) can be supported by the process tube 2, the structure for supporting the heat equalizing tube in the conventional example becomes unnecessary, and the structure of the heat treatment furnace can be simplified accordingly. . Further, the fibrous heat equalizing member 3 is less expensive than the above-described heat equalizing tube, has a long life without cracking, and depends on the degree of breakage even if partial breakage occurs. It is possible to perform a partial repair, and to configure a heat treatment furnace that can be easily handled at low cost.
[0015]
In the above description, the configuration in which the heat equalizing member 3 is wound around the outer surface of the process tube 2 and covered on the outer surface has been described. However, the present invention is not limited to this. 3 may be formed in a bag shape corresponding to the outer shape of the process tube 2 and put on the outer surface thereof. When the heat equalizing member 3 is formed in a bag shape in this manner, the heat equalizing member 3 can be easily attached to and detached from the outer surface, and the work of attaching the heat equalizing member 3 when the process tube 2 is replaced can be easily performed. It can be carried out.
[0016]
【The invention's effect】
The present invention configured as described above has the following effects.
According to the heat treatment furnace of the first aspect, since the heat equalizing means is constituted by the fibrous heat equalizing member covered on the outer surface of the process tube, the distance between the process tube and the heater is reduced to reduce the heat treatment furnace. Can easily be miniaturized. Further, since the soaking means can be supported by the process tube, the structure of the heat treatment furnace can be simplified. Further, unlike the conventional heat equalizing tube, the fibrous heat equalizing member has a long life without cracking. It is possible to construct a heat treatment furnace which can be performed at low cost and can be easily handled.
[0017]
Further, according to the heat treatment furnace of the second aspect, since the heat equalizing member is formed of the continuous fiber molded into a predetermined shape, the heat equalizing member can be easily covered on the outer surface of the process tube. .
[0018]
Further, according to the heat treatment furnace of the third aspect, since the heat equalizing member is formed in a bag shape, the work of attaching the heat equalizing member to the process tube can be easily performed.
[Brief description of the drawings]
FIG. 1 is a schematic sectional view showing a heat treatment furnace according to one embodiment of the present invention.
FIG. 2 is a schematic sectional view showing a conventional heat treatment furnace.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Heater 2 Process tube 3 Heat equalizing member (heat equalizing means)

Claims (3)

A cylindrical heater, a process tube disposed inside the heater, and a heat equalizing unit provided between the heater and the process tube, for uniformly transmitting radiant heat from the heater to the process tube. Heat treatment furnace,
The heat treatment furnace, wherein the heat equalizing means is constituted by a fibrous heat equalizing member covered on an outer surface of the process tube. The vertical furnace according to claim 1, wherein the heat equalizing member is formed of continuous fibers molded into a predetermined shape. The heat treatment furnace according to claim 1, wherein the heat equalizing member is formed in a bag shape.

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