JP2002181459A - Heat treatment furnace - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a heat treatment furnace to easily reduce the size of the structure of the heat treatment furnace and simplify and be easily handled at low cost. SOLUTION: The outside surface of a process tube 2 is covered by a soaking member (an equalizing means) 3. By the soaking member 3, a radiation heat from a heater 1 is evenly conducted to the process tube 2, and a treatment temperature in the process tube 2 is uniformalized.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. 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 treatment such as diffusion.

[0002]

In the case of forming a silicon oxide film (SiO ₂₎ or the like of the Related Art of the semiconductor wafer surface, a vertical heat treatment furnace shown in FIG. 2 are used, for example. Referring to FIG. 1, this conventional heat treatment furnace includes a cylindrical heater 50 and its heater 50.
A heat equalizing tube 51 and a process tube 52 are sequentially arranged concentrically at a predetermined interval inside.
The heater 50 is covered with a heat insulating wall 50a.
The heat insulating wall 50a is supported by the heater base 53.

[0003] The heat equalizing tube 51 includes a process tube 52.
Is formed, for example, by sintering silicon carbide (SiC) according to the external shape of, and uniformly transmits radiant heat from the heater 50 to the process tube 52. As shown in the figure, the heat equalizing tube 51 has an open lower end, is mounted 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 52 a at a lower portion of the outer periphery thereof. A tube support 5 is provided between the upper surface of the flange 52 a and the heat equalizing tube support 54.
5, the tube support 55 and the skirt 56
The flange 52a is clamped by these.

In this heat treatment furnace, a furnace port door 57 which can be opened and closed is provided below the process tube 51, and a semiconductor wafer is placed between the inside of the process tube 51 and the load chamber 58. An elevating device 59 for carrying in and out W is provided. As described above, in this conventional heat treatment furnace, the soaking tube 51 serving as a soaking unit 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]

However, in the above-described conventional heat treatment furnace, the heat equalizing pipe 51 and the process tube 52 are arranged inside the heater 50 at predetermined intervals. There is a problem that it is difficult to reduce the inner diameter, and it is difficult to reduce the size of the heat treatment furnace. Further, as shown in FIG. 2, a heat equalizing tube support 54 and a tube support 55
1 and the process tube 52, the furnace port structure became complicated. In addition, soaking tube 5
No. 1 is expensive and is liable to be damaged such as cracks, and it has been required to pay close attention to its handling.

SUMMARY OF THE INVENTION In view of the above-mentioned conventional problems, the present invention provides a heat treatment furnace that can be easily miniaturized and simplified in structure and can be easily handled at low cost. The purpose is to do.

[0007]

A heat treatment furnace according to the present invention is provided with a cylindrical heater, a process tube disposed inside the heater, and a heater provided between the heater and the process tube. A heat treatment furnace having a heat equalizing means for uniformly transmitting radiant heat to a process tube, wherein the heat equalizing means is constituted by a fibrous heat equalizing member covered on an outer surface of the process tube. It is characterized by the following (claim 1).

In the heat treatment furnace configured as described above, the heat equalizing means provided between the heater and the process tube is constituted by the fibrous heat equalizing member covered on the outer surface of the process tube. By reducing the distance between the process tube and the heater, the structure of the heat treatment furnace can be easily reduced in size. Further, since the heat equalizing member can be supported by the process tube, the structure of the heat treatment furnace can be simplified.

Further, the heat treatment furnace as described above (Claim 1)
In the above, the heat equalizing member may be constituted by 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 above heat treatment furnace (claim 1 or 2), it is preferable that the heat equalizing member is 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]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the heat treatment furnace of the present invention will be described below 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 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.

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 is provided with a flange 2a protruding from a lower portion of the outer periphery. 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 therein.

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)). Over the outer surface by being wrapped directly or singly around the outer surface. 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 the silicon oxide film or the like on the surface of the semiconductor wafer W is formed. Processes such as film formation 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 in 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.

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 heat equalizing tube in the above-described conventional example is used. The distance between the process tube 2 and the heater 1 can be made smaller than in the case where the heat treatment furnace is used, 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 way, 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. In addition, the heat equalizing member 3
Since the (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.
Furthermore, the fibrous heat equalizing member 3 is less expensive than the above-described heat equalizing tube, has a long life without cracking, and even if a part of the member is damaged, depending on the degree of the damage. A heat treatment furnace that can perform partial repair and that can be easily handled at low cost can be configured.

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. The heat equalizing member 3 may be formed in a bag shape corresponding to the outer shape of the process tube 2, and may be configured to cover 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 replacing the process tube 2 or the like can be easily performed. It can be carried out.

[0016]

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. Can easily be miniaturized. Further, since the heat equalizing means can be supported by the process tube, the structure of the heat treatment furnace can be simplified. Also, unlike the conventional heat equalizing tube, the fibrous heat equalizing member has a long life without cracking, and even if partial damage occurs, partial repair may be required depending on the degree of damage. It is possible to construct a heat treatment furnace which can be performed at low cost and can be easily handled.

Further, according to the heat treatment furnace of the present invention, since the heat equalizing member is formed of continuous fibers molded into a predetermined shape, the heat equalizing member can be easily covered on the outer surface of the process tube. be able to.

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)

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 4K063 AA05 AA19 BA12 CA04 CA08 FA02 5F045 AA20 AB32 DP19 DQ04 EC02 EC05 EK06 EK21

Claims (3)

[Claims] 1. A cylindrical heater, a process tube disposed inside the heater, and a heater provided between the heater and the process tube to uniformly transmit radiant heat from the heater to the process tube. A heat treatment furnace provided with a heat equalizing means, wherein the heat equalizing means is constituted by a fibrous heat equalizing member covered on an outer surface of the process tube. 2. The heat equalizing member according to claim 1, wherein the heat equalizing member is made of continuous fibers molded into a predetermined shape.
Vertical furnace as described. 3. The heat treatment furnace according to claim 1, wherein the heat equalizing member is formed in a bag shape.