JPH0216723A - Tubular member for semiconductor thermal treatment furnace - Google Patents

Abstract

PURPOSE:To increase the number of wafers subjected to a thermal treatment per batch by a method wherein an increased heat capacity part is provided on at least one of the gas introducing inlet side end part and the opening side end part of a straight tube part and the rate of heat radiation to the heat capacity of that part is reduced and the temperature decline at that part is suppressed. CONSTITUTION:Thick parts 1c and 1d are formed solidly on the outer circumferential parts of a straight tube part 1a, i.e., the gas introducing inlet 2 side end part and the opening part 3 side end part through which semiconductor wafers are carried in and out, as increased heat capacity parts where the heat capacities of both the end aprts are increased. The heat capacities of the thick parts 1c and 1d are controlled by adjusting the lengths and thicknesses of those parts. The heat capacities of the inlet 2 side end part and the opening 3 side end part become larger compared to the capacity of the middle part and the rate of heat radiation to the heat capacity is reduced at both the end parts. With this constitution, the temperature decline at those parts is suppressed and the number of wafers subjected to a thermal treatment per batch can be increased.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to tubular members such as process tubes and liner tubes used in semiconductor heat treatment furnaces that perform thermal diffusion or thermal oxidation treatment on semiconductor wafers.

[Prior Art] Conventionally, tubular members such as process tubes and liner tubes are provided with a straight pipe portion having a uniform wall thickness.

On the other hand, no heater is provided at the end on the gas inlet side, which is the supply side of the processing gas, in the semiconductor heat treatment furnace, and at the end on the opening side, which is the inlet/outlet to the semiconductor wafer.

(Problem B to be Solved by the Invention) Therefore, according to the conventional tubular member for a semiconductor heat treatment furnace, the length of the soaking part cannot be made long due to heat dissipation from the gas inlet side and the opening side.

In order to increase the length of the soaking section (heat soaking length), it is necessary to make the tubular member longer and the furnace body larger, or it is necessary to divide the heater into multiple parts in the axial direction and reduce the amount of heat generated at both ends. need to be controlled.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a tubular member for a semiconductor heat treatment furnace whose soaking length can be increased without increasing the length of the tubular member or controlling the amount of heat generated by the heater.

(Means for Solving the Problems) In order to solve the above problems, the present invention provides a heat capacity increasing portion at at least one of the gas inlet side end portion or the opening side end portion of the straight pipe portion.

It is preferable that the heat capacity increasing part is a thick part provided on the outer periphery of the straight part.

Alternatively, the heat capacity increasing portion may be a plurality of fins provided on the outer periphery of the straight portion.

[Effect]

According to the above means, the ratio of the amount of heat radiation to the heat capacity of at least one of the end on the gas inlet side and the end on the opening side becomes small, and the temperature drop in that part is reduced.

The heat capacity of the heat capacity increasing portion is controlled by adjusting the length and wall thickness of the thick wall portion or the wall thickness, height, and number of fins.

(Example) Hereinafter, an example of the present invention will be described with reference to FIGS. 1 to 3.

FIG. 1 is a partially cutaway sectional side view of the tubular member for a semiconductor heat treatment furnace of the first embodiment.

The tubular member 1 of this embodiment has a conical gas introduction part 1b equipped with a gas introduction port 2 that serves as an inlet for the processing gas at one end (the left end in the figure) of a cylindrical straight pipe part 1a. This is a process tube. Further, on the outer periphery of the straight pipe portion 1a, the end on the side of the gas inlet 2 and the end on the side of the opening 3 at the other end through which semiconductor wafers are taken in and taken out, there is a thick walled portion that becomes a heat capacity increasing portion that increases the heat capacity of both parts. 1c.

1d is provided integrally.

The heat capacity of the thick portions 1c and ld is controlled by adjusting the length and thickness of these portions.

According to the tubular member 1 of the first embodiment, the heat capacity at the end on the gas inlet 2 side and the end on the opening 3 side is larger than that at the middle part, and the ratio of the heat radiation amount to the heat capacity at both ends is small. This reduces the temperature drop.

Therefore, the soaking length becomes longer than when the thickness of the straight pipe portion 1a is negative, and the number of semiconductor wafers processed per batch can be increased.

FIG. 2 is a partially cutaway cross-sectional side view of the tubular member for a semiconductor heat treatment furnace according to the second embodiment.

The tubular member 1' of this embodiment is a process tube in which a gas introduction part 1b is connected to one end of a straight pipe part 1a, similar to that of the first embodiment.
On the outer periphery of the side end portion and the opening 3 side end portion, annular compound failure twins le and if, which serve as heat capacity increasing portions, are integrally provided.

The heat capacity of the fins le and if is controlled by adjusting their thickness, height, and number.

Therefore, according to the tubular member 1' of the second embodiment, the first
The same effects as the tubular member 1 of the embodiment can be obtained.

FIG. 3 is a partially cutaway cross-sectional side view of the tubular member for a semiconductor heat treatment furnace according to the third embodiment.

The tubular member 1'' of this embodiment is a liner tube fitted around the outer periphery of the process tube, and both ends of the cylindrical straight tube portion 1a correspond to the gas inlet side end and the opening side end of the process tube. A plurality of annular fins Ig and lh, which serve as a heat capacity increasing section, are integrally provided on the outer periphery of the section.

Therefore, according to the tubular member 1″ of the third embodiment, the first
．． The same effects as the tubular member 1.1' of the second embodiment can be obtained.

Specific example 1 A 5tc-st process tube with an outer diameter of 205 mm, an inner diameter of 190 mm, and a length of 3000 mm has a wall thickness of 7.5 m on the outer periphery of the straight pipe portion of the gas inlet side end and the opening side end.
When five fins of 30 mm height were attached at 25 mm intervals and the soaking length inside the process tube was measured, it was 1340 mm, which is the same as the soaking length (900 mm) of the same size process tube without conventional fins. 49
% increase.

Specific example 2 Five fins with a wall thickness of 7.5 mm and a height of 30 mm were placed at intervals of 25 mm on the outer periphery of both ends of the straight pipe part of a liner tube made of 5iC-5i with an outer diameter of 230 mm, an inner diameter of 215 mm, and a length of 1700 mm. A quartz glass process tube with an outer diameter of 182 mm, an inner diameter of 175 mm, and a length of 2300 mm was inserted inside this liner tube, and the soaking length inside the process tube was measured.
The length was 40 mm, which is 40% longer than the conventional soaking length (600 mm) in the same process tube using a liner tube of the same size without fins.

In each of the above embodiments, the heat capacity increasing portions are provided on the outer periphery of both ends of the straight pipe portion 1a, but the heat capacity increasing portions are provided only at one end where the amount of heat dissipation is particularly large. Good too.

In addition, the thick portions 1c, ld and fins 1, which become heat capacity increasing portions,
e, if, Ig, and 1h are not limited to the case where they are provided integrally with the straight pipe portion 1a, but separate members may be fitted. In this case, the separate member is desirably made of the same material as the straight pipe portion 1a or made of a highly purified material.

Furthermore, the fins are not limited to an annular shape, and may be, for example, strip-shaped extending in the axial direction of the straight pipe portion 1a.

〔Effect of the invention〕

As described above, according to the present invention, the ratio of the amount of heat radiation to the heat capacity of at least one of the gas inlet side end and the opening side end becomes small, and the temperature drop in that part is reduced, which is different from the conventional method. In addition, the soaking length can be increased without increasing the length of the tubular member or controlling the amount of heat generated by the heater, and as a result, the number of semiconductor wafers to be heat-treated per patch can be increased.

[Brief explanation of the drawing]

The figures show embodiments of the present invention, and FIGS. 1, 2, and 3 omit a part of the tubular member for a semiconductor heat treatment furnace of the first embodiment, the second embodiment, and the third embodiment, respectively. It is a half-cut cross-sectional side view. 1a... Straight pipe part 1b... Gas introduction part 1
c, 1d...thick wall part le, if, Ig, 1h...=fin 2...gas inlet 3...opening 1st d 2nd Σ Fig. 3

Claims (1)

[Claims] (1) A tubular member for a semiconductor heat treatment furnace, characterized in that a heat capacity increasing portion is provided on at least one of the gas inlet side end or the opening side end of the straight pipe portion.