JPH0691031B2 - Diffusion furnace device - Google Patents

Description

TECHNICAL FIELD The present invention relates to a diffusion furnace device.

[Prior Art] Conventionally, in this type of diffusion furnace apparatus, as shown in FIG. 2, a heater portion 1 is arranged on the outer periphery of a soaking tube 2 that is installed on a furnace core tube 3, and a soaking tube 2 and a heater portion 1 are provided. A cooling passage 8 for allowing a cooling medium to flow in the length direction of the soaking tube 2 is formed between them, and a blower 5 supplies cooling gas or cooling air 6 from one pipe end 2a of the soaking tube 2 into the cooling passage 8. The furnace body is cooled by sending it out and exhausting it from the other pipe end 2b. The exhausted gas or air is cooled by the cooler 7 and discharged.

[Problems to be Solved by the Invention] In the above-described conventional diffusion furnace apparatus, as shown in FIG. 2, one tube end 2a of the furnace body is passed through the central portion 2c to the other tube end 2b.
In order to make the cooling gas flow toward the side, for example, in the soaking tube 2, the pipe end 2a side is cooled more rapidly than the central portion 2c, and there is an increasing temperature gradient between the central portion 2c and the pipe end 2a. This has been a cause of damage to the soaking tube 2 and the like due to thermal stress.

An object of the present invention is to provide a diffusion furnace device in which the temperature gradient between the central portion of the furnace body and the tube end is suppressed to be small and the furnace body is cooled.

[Means for Solving the Problems] In order to achieve the above object, the diffusion furnace apparatus according to the present invention is a diffusion furnace apparatus having a soaking tube, a heater section, and a cooling passage, which is a soaking tube and a heater. The section is a tubular shape and is combined with an inner and outer double structure to form a furnace body, the soaking tube accommodates the furnace core tube, and the heater section is the entire length in the longitudinal direction of the soaking tube. The cooling passage is formed in the gap between the soaking tube and the heater part, the refrigerant outlet is opened in the center part, and the refrigerant blown inside is cooled from the center to both tubes. It serves as a flow path for the refrigerant that branches and flows at the end.

[Embodiment] Next, an embodiment of the present invention will be described with reference to the drawings.

FIG. 1 is a vertical sectional view showing a diffusion furnace according to the present invention. In FIG. 1, a soaking tube 2 is housed in a heater 1, and a furnace core tube 3 is housed therein. Semiconductor substrate (wafer) 4
Is heat-treated in the furnace core tube 3. The soaking tube 2 and the heater part 1 are tubular bodies, and are combined inside and outside to form a furnace body. Further, there is a gap between the heater 1 and the heat equalizing pipe 2, and the present invention uses this gap as the cooling passage 8 through which the refrigerant 6 flows in the length direction of the furnace body, and is placed at the center position of the heat equalizing pipe 2. Refrigerant blow-out holes 5a of the blower (cooling source) 5 are opened in the corresponding cooling passages 8. The blown out gas 6 flows along the soaking tube 2 from the central portion 2c to both tube ends 2a, 2
After branching to b, it is discharged from both ends of the pipe, cooled by the cooler 7, and then discharged.

The diffusion furnace apparatus of the present invention has a structure in which in order to reduce the temperature gradient, the soaking tube 2 is cooled from the high temperature central portion 2c to reduce the temperature difference from the tube end of the low temperature portion.
Further, the gas (air) for cooling is used to remove heat in the central portion 2c and the heated gas radiates the heat at the pipe ends 2a and 2b in the low temperature portion, so that the temperature gradient tends to be further reduced.

[Effects of the Invention] As described above, according to the present invention, since the cooling is performed from the highest temperature portion without increasing the temperature gradient in the furnace when the temperature of the heater is lowered, the soaking tube and the like are prevented from being damaged by thermal stress. There is an effect that can be done.

[Brief description of drawings]

FIG. 1 is a sectional view of a diffusion furnace of the present invention. FIG. 2 is a sectional view of a conventional diffusion furnace. 1 ... Heater part, 2 ... Soaking tube 3 ... Furnace core tube 4 ... Semiconductor substrate (wafer) 5 ... Blower (cooling source)

Claims (1)

[Claims] 1. A diffusion furnace apparatus having a soaking tube, a heater section, and a cooling passage, wherein the soaking tube and the heater section have a tubular shape and are combined into an inner and outer double structure to form a furnace body. The soaking tube accommodates the furnace core tube, the heater section heats the circumferential surface along the entire length of the soaking tube in the longitudinal direction, and the cooling passage has the soaking tube and the heater section. It is characterized in that it is formed in a gap between them, and that a refrigerant outlet is opened at a central portion thereof, which serves as a refrigerant flow path for branching and flowing the refrigerant blown out from the center to both pipe ends. Diffusion furnace equipment.