JPH017727Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a heating furnace for a vapor phase growth apparatus for silicon, etc., and particularly to a radiation heating furnace for a cylinder type vapor phase growth apparatus.

In conventional vapor phase growth equipment for thin films of semiconductors such as silicon, a wafer is placed on a susceptor installed in a reaction chamber, a reaction gas is supplied into the reaction chamber, and the susceptor is heated, thereby depositing silicon, etc. on the wafer. Semiconductor thin films are grown in the vapor phase.

In such devices, heating methods for the susceptor are broadly divided into induction heating methods, which heat the susceptor using, for example, a high-frequency induction heating coil, and radiation heating methods, which generally heat the susceptor using radiant heat using an infrared lamp. Of these, the induction heating method first heats the susceptor and then heats the wafer mounted on it, so there is less slippage compared to the radiation heating method, which can heat the susceptor and wafer at the same time. It has disadvantages such as easy occurrence.

FIG. 1 shows a conventional cylinder type vapor phase growth apparatus using radiation heating. A susceptor 4 is provided inside the reaction tube 3, which forms a reaction chamber for growing a semiconductor thin film such as silicon, and is suspended from, for example, a hanger (not shown) and is rotatable in both left and right directions around a rotation axis S. There is. Generally, the susceptor 4 has a polyhedral cylinder shape, and its rotation axis S is provided so as to substantially coincide with the central axis of the reaction tube 3. A plurality of wafers 5 are placed on each surface of the susceptor 4, and vapor phase growth of silicon or the like is performed by supplying a reactive gas. As shown in FIG. 2, a plurality of rod-shaped infrared lamps 1 as heat sources are arranged in a tiered manner around the outer circumference of the reaction tube 3 (hereinafter referred to as a lamp unit). In addition, in order to make effective use of the radiant energy of the heated part, an infrared lamp 1 is installed.
Reflector plate 2 having a concave surface such as a paraboloid near the back surface of
has been established. In such a configuration, the heating temperature distribution of the object to be heated in the heating furnace, that is, the wafer 5 is the first one.
As shown in the figure, direct radiant energy a from the infrared lamp 1 and reflected energy b from the reflector 2
The total heat energy of each infrared lamp 1
This is a mountain-shaped temperature distribution curve of heating energy with a peak at the center. However, when infrared lamps 1 are placed around the reaction tube 3 as a heating source, a plurality of infrared lamps 1 are usually placed at equal intervals (Figs. 1 and 2) and at the same level in the length direction of the heating furnace. The temperature distribution due to the heating source is shown by curve T in FIG. During actual operation, the susceptor 4 rotates in both left and right directions at an appropriate period inside the reaction tube 3, and this rotation also changes the relative position of the infrared lamp 1 and the susceptor 4 in the vertical direction. is constant and will not change in any way. In addition, especially when performing vapor phase growth with the inside of the reaction tube 3 in a reduced pressure state,
Since the convection of the reaction gas becomes inactive, the temperature distribution gradient remains unchanged, and such a temperature gradient at which the wafer 5 is heated causes thickness unevenness in the grown layer and occurrence of slips due to thermal stress.

An object of the present invention is to provide a heating furnace for a vapor phase growth apparatus that uses an infrared lamp as a heating source and that makes the temperature distribution of a heated object uniform.

The heating furnace of the vapor phase growth apparatus according to the present invention, which is provided to achieve the above object, includes a plurality of lamp units disposed around the outer periphery of a reaction vessel, and a rotating shaft of a susceptor that is rotatable within the reaction vessel. The lamp unit is characterized in that the axes of the plurality of rod-shaped lamps arranged in steps in the lamp unit are arranged at an angle with respect to a direction perpendicular to the lamp unit.

The present invention will be described in more detail below in conjunction with embodiments of the accompanying drawings.

FIG. 4 shows an embodiment of the heating furnace of the cylinder type vapor phase growth apparatus according to the present invention. In the figure, the same members as in FIG.

In this embodiment, the infrared lamp 11 is arranged at an angle θ, as shown in FIG. 5, with respect to the rotation axis S of the susceptor 5 on which the wafer 5 for vapor phase growth is placed. Therefore, infrared lamp 1
The reflecting plate 12 having a concave surface provided behind the reflecting plate 1 is also inclined by the same angle θ.

In this way, the rod-shaped infrared lamp 11 is arranged at an angle of θ with respect to the rotation axis S of the susceptor 5, and the lamp unit arranged as shown in FIG. Since a plurality of susceptors are provided on the outer periphery, the susceptors 5 rotate left and right around the rotation axis S, so that any one point on the wafer 4 always crosses the center line of the infrared lamp 11.

Therefore, the heating temperature distribution of the wafer is made uniform, and the intended purpose can be achieved.

Furthermore, as already mentioned, since the heating furnace of a cylinder-type lamp-heated vapor phase growth apparatus generally surrounds the reaction tube 3 with a lamp unit comprising a plurality of surfaces, the inclination angle of the infrared lamp 11 is As shown in FIG. 5, it is preferable that θ is provided such that the two opposite ends that are vertically adjacent to each other coincide with each other on the horizontal plane or overlap each other on the horizontal plane, but it is not limited to this, for example. , the center line of the lamp 11 in the developed view of the heating surface of the lamp provided around the reaction tube 3 (this example shows the case where four lamp units are used) as shown in FIG. may be configured to be continuous as a single lead forming an angle θ. In any of the embodiments, the amount of overlap can be arbitrarily determined in consideration of the effective heating length by the lamp.

According to the present invention, by arranging the infrared lamp as a wafer heating source around the reaction tube at an appropriate angle θ with respect to the rotation axis of the susceptor, temperature unevenness of the wafer, which is the object to be heated, is reduced. Therefore, a high-quality vapor-deposited wafer without slips or the like can be obtained.

[Brief explanation of the drawing]

Figure 1 is a schematic vertical cross-sectional view of a heating furnace of a conventional cylinder-type radiation heating type vapor phase growth apparatus, and Figure
A schematic diagram of the lamp unit viewed from the - line direction in the figure, Figure 3 is a heating temperature distribution diagram by the lamp unit shown in Figure 2, and Figure 4 is a heating furnace of the cylinder type radiation heating type vapor phase growth apparatus according to the present invention. 5 and 6 are schematic cross-sectional views of embodiments showing the arrangement of infrared lamps according to the present invention. 1, 11...Infrared lamp, 2, 12...Reflector, 3...Reaction tube, 4...Susceptor, 5...Wafer, S...Susceptor rotation axis.

Claims (1)

[Claims for Utility Model Registration] 1 A plurality of lamp units are disposed around the outer periphery of a reaction vessel, and a wafer placed on a susceptor rotatably provided within the reaction vessel is heated to cause vapor phase growth. In the heating furnace of the vapor phase growth apparatus, the axis of each of the plurality of rod-shaped lamps arranged in steps in each of the lamp units is inclined with respect to the direction perpendicular to the rotation axis of the susceptor. Equipment heating furnace. 2. The lamp according to claim 1 of the utility model registration, which is provided such that the opposite ends of the vertically adjacent lamps overlap each other among the plurality of rod-shaped lamps arranged in steps in the lamp unit. Heating furnace for phase growth equipment. 3. The rod-shaped lamps provided in the plurality of lamp units are arranged in a direction centered on the rotation axis of the susceptor.
The heating furnace of the vapor phase growth apparatus according to claim 1, which is arranged so as to be located on the lead line of the strip.