JPS6116686Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a substrate holding boat that holds a substrate during heat treatment of the substrate.

Hereinafter, a description will be given of an example of a substrate holding boat that holds a semiconductor substrate when the semiconductor substrate is subjected to heat treatment.

FIG. 1 is a perspective view showing a state in which a semiconductor substrate is placed on a conventional substrate holding boat. In FIG. 1, 1 is a semiconductor substrate, 2 is a substrate holding boat made of quartz glass, and holds the semiconductor substrate 1;
2 is a frame of the substrate holding boat 2, and 22 is a plurality of grooves formed in the upper part of the frame 21.

FIG. 2 is a sectional view showing a state in which a semiconductor substrate is heat treated in a heat treatment furnace. In FIG. 2, 3 is a heat treatment furnace, 31 is a heating furnace body, 32 is a quartz tube with a circular cross section and is a reaction tube in which heat treatment is carried out, and 321 is a carrier gas supplied to the quartz tube 32. A gas inlet for introducing gas, 322 is a quartz tube 3
This is a gas exhaust port for discharging carrier gas from 2. FIG. 3 is a front view of a conventional substrate holding boat shown together with a cross section of a quartz tube.

As shown in FIG. 1, a semiconductor substrate 1 is placed on a substrate holding boat 2, and this substrate holding boat 2 is
, as shown in FIGS. 2 and 3, in a heat treatment furnace 3.
Then, heat treatment such as impurity diffusion and thermal oxide film growth into the semiconductor substrate 1 is performed. At this time, friction occurs at the contact point between the quartz tube 32 and the substrate holding boat 2 (indicated by P in FIG. 3) each time the substrate holding boat 2 is inserted into and taken out of the quartz tube 32.

In recent years, the diameter of the semiconductor substrate 1 has been increasing to improve the yield of semiconductor devices, and a diameter of 3 to 5 inches is used, but in this case, the frictional force becomes very large. In addition, the quartz glass fragments generated during friction adhere to the surface of the semiconductor substrate 1 at high temperatures, thereby degrading various properties of the semiconductor substrate 1.

In order to eliminate these problems, in recent years,
A method is used in which a boat for holding a substrate is placed on a boat pedestal called a paddle and equipped with wheels. In this conventional device in which a holding boat is mounted on a boat pedestal, the inner diameter of the quartz tube must be increased. However, when pursuing economical efficiency in heat treatment of semiconductor substrates, it is desirable to use a quartz tube with a diameter as small as possible to process a semiconductor substrate of the maximum allowable diameter.

This idea was made in view of the above circumstances, and wheels are provided at both ends of an axle that straddles the top surface of the boat body of the board holding boat and is rotatably supported by the boat body. The lower part of the outer circumference of the boat is prevented from protruding below the lower surface of the boat body to reduce friction with the reaction tube of the heat treatment furnace, and
The object of the present invention is to provide a substrate holding boat that does not require increasing the inner diameter of the reaction tube.

This invention will be explained below based on examples.

FIG. 4 is a perspective view showing a state in which a semiconductor substrate is placed on an embodiment of the substrate holding boat according to this invention, and FIG. 5 is a front view of the substrate holding boat of the embodiment shown together with a cross section of a quartz tube. . In Figures 4 and 5, the same reference numerals as in Figures 1 to 3 refer to 1.
It represents something similar to that shown in FIGS. 4 is a substrate holding boat of the embodiment; 41 is a frame made of quartz glass and constitutes the boat body of the substrate holding boat 4; 42 is a large number of grooves formed in the upper part of the frame 41; 43 is made of quartz glass; The axle 44 is made of quartz glass and is fused to both ends of the axle 43. The axle 44 is made of quartz glass and is fused to both ends of the axle 43. It is made so that it does not protrude below the lower surface of the frame body 41. A bearing 45 is made of quartz glass and rotatably supports the axle 43, which has both ends fused to the frame 41.

When the substrate holding boat 4 of the embodiment is inserted into the quartz tube 32, the frame body 41 is 1 to 3 mm apart from the quartz tube 32.
The quartz tube 32 and the wheel 44 come into contact at a contact point Q shown in FIG.
The frame body 41 and the quartz tube 32 are separated. Since the axle 43 is located above the frame 41, the position of the frame 41 within the quartz tube 32 is almost unchanged compared to when the conventional substrate holding boat 2 is used. Therefore, even if the substrate holding boat 4 of the embodiment is used, there is almost no need to increase the inner diameter of the quartz tube 32. Therefore, efficient heat treatment of the semiconductor substrate 1 is possible.

Furthermore, when the substrate holding boat 4 is moved in and out of the quartz tube 32, the rolling of the wheels 44 is used.
Since the friction between the substrate holding boat 4 and the quartz tube 32 is significantly reduced, the work becomes smoother, and the occurrence of crushed quartz glass particles is extremely reduced, thereby preventing deterioration of the characteristics of the semiconductor substrate 1 due to the crushed particles. Ru.

In the above embodiment, the case where the boat body of the substrate holding boat is a frame body is described.
This invention can also be applied to a substrate holding boat whose main body is a plate-shaped body or a rod-shaped body.

In addition, in the above embodiment, all the components of the substrate holding boat were made of quartz glass, but at least some of the components could be made of other heat-resistant materials, such as silicon carbide. , silicon, alumina ceramics, etc., similar effects can be obtained.

Furthermore, in the above embodiment, a substrate holding boat used when heat treating a semiconductor substrate was described, but this idea can also be applied to a substrate holding boat used when heat treating a substrate other than a semiconductor substrate. be able to.

As explained above, the substrate holding boat according to this invention has wheels at both ends of an axle that sits on the top surface of the main body of the substrate holding boat and is rotatably supported by the main body. The lower part of the outer circumference of the wheel is designed so that it does not protrude below the bottom surface of the boat body, and the rolling of the wheel against the inner wall of the heat treatment tube is used to insert it into the reaction tube. The friction between the substrate and the reaction tube is significantly reduced, making work smoother, and the generation of crushed powder due to friction is extremely reduced, making it possible to prevent deterioration of the characteristics of the substrate due to crushed powder. Furthermore, since there is almost no need to increase the inner diameter of the reaction tube, efficient heat treatment can be performed.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing a state in which a semiconductor substrate is placed on a conventional substrate holding boat, and FIG. 2 is a cross-sectional view showing a state in which a semiconductor substrate is heat-treated in a heat treatment furnace.
FIG. 3 is a front view of a conventional substrate holding boat shown together with a cross section of a quartz tube, FIG. 4 is a perspective view showing a state in which a semiconductor substrate is placed on an embodiment of the substrate holding boat according to this invention, and FIG. The figure is a front view of the substrate holding boat of the embodiment shown together with a cross section of a quartz tube. In the figure, 1 is a semiconductor substrate (substrate to be processed);
3 is a heat treatment furnace, 32 is a quartz tube (reaction tube), 4 is a substrate holding boat of the embodiment, 41 is a frame (boat body), 43 is an axle, and 44 is a wheel. Note that the same reference numerals in the figures indicate the same or corresponding parts.

Claims (1)

[Scope of utility model registration request] At least two axles are mounted on the upper surface of the boat body on which the substrate to be processed is placed and held, and are rotatably supported by the boat body, and at least two axles are provided at both ends of the axles, and the lower part of the outer circumference is The boat is equipped with an axle that does not protrude below the bottom surface of the boat body, and uses the rolling movement of the axle in contact with the inner wall of the reaction tube to move the substrate into the reaction tube of the heat treatment furnace while holding the substrate to be processed. A boat for holding substrates.