JPH0744158B2 - Semiconductor element manufacturing furnace - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to a semiconductor element manufacturing furnace such as an integrated circuit. More specifically, a semiconductor such as silicon is subjected to heat treatment for oxidation or diffusion. Oxidation / diffusion furnace

[Prior art]

Conventionally, a furnace generally used for oxidation or diffusion in a semiconductor manufacturing process is configured as shown in FIG.

That is, this furnace is arranged between a furnace tube 1 made of quartz capable of accommodating a semiconductor wafer to be processed, a heater 2 surrounded to heat the furnace tube 1, and the furnace tube 1 and the heater 2. The heat soak zone 3 prevents the contamination from the heater 2 and makes the radiant heat from the heater 2 uniform.

With such a furnace, for example, the diffusion process is performed on the wafer surface at a furnace temperature by passing a gas containing atoms as appropriate impurities through a furnace tube.

In such a manufacturing furnace, the repetitiveness and uniformity of the processed material are
It is well known that it is obtained by temperature stability and uniformity in the furnace. Therefore, it is important and essential to measure and control the temperature in the furnace and prevent contamination in the furnace to maintain uniformity.

In the conventional furnace, in order to prevent contamination in the furnace and control the temperature, the temperature was measured using a thermocouple and outside the furnace tube. Further, the temperature inside the furnace is separately measured before the work processing step, and the heater current is controlled so as to correct the temperature obtained by the external measurement based on the temperature inside the furnace.

[Problems to be solved by the invention]

However, as described above, in the conventional furnace, the temperature inside the furnace was controlled according to the external temperature obtained outside the furnace tube. Was not always able to follow. In order to solve this point, it is only necessary to measure the external temperature that is close to the temperature inside the furnace. Therefore, it is possible to remove the soaking tube. I couldn't.

An object of the present invention is to provide a semiconductor device manufacturing furnace capable of measuring the temperature in the furnace under working conditions in real time and improving the repetitiveness and uniformity of the material to be processed.

[Means for solving problems]

That is, the above-mentioned object of the present invention comprises a hollow cylindrical body,
It has a quartz tube capable of accommodating a semiconductor wafer to be processed, and a soaking tube and a heater which are sequentially arranged outside the quartz tube so as to surround the quartz tube, and the quartz tube is heated by the heater. In a semiconductor element manufacturing furnace for processing the semiconductor wafer at a high temperature, the quartz tube has a double structure in which the quartz tube is fitted in a loose fit state, and the quartz tube is provided between the inner quartz tube and the outer quartz tube. This is achieved by a furnace for manufacturing a semiconductor device, which is provided with at least one thermocouple for measuring the internal temperature of the other quartz tube.

[Action]

Since the thermocouple measures the temperature inside the furnace while it is housed between the inner quartz tube and the outer quartz tube, the inside of the furnace tube cannot be Does not affect the reaction of.

〔Example〕

 Embodiments of the present invention will be described below with reference to the drawings.

1 and 2 show a semiconductor device manufacturing furnace 1 according to the present invention.
Fig. 2 shows an embodiment, and Fig. 2 shows a cross section of the main part of the furnace shown in Fig. 1. In this embodiment, a diffusion furnace will be described as an example.

In the diffusion furnace 10 having a double quartz tube structure to which the present invention is applied, two hollow cylindrical quartz tubes 11 and 12 having different diameters are loosely fitted along the longitudinal direction. Soaking tube 13 arranged so as to include two quartz tubes 11 and 12,
An electric furnace 14 comprising a heater arranged on the outer surface of the soaking tube 13.
And are equipped with. The quartz tubes 11 and 12 are made of quartz, and the inner quartz tube 11 is provided so that a silicon wafer 16 in which diffusion is performed can be housed inside. Further, the inner quartz tube 11 and the inner quartz tube 11 and the outer quartz tube 12 are provided so that a gas flow is supplied, and the inner quartz tube 11 and the outer quartz tube 12 are provided. Between the quartz tube 12 and the quartz tube 12, at least one thermocouple is accommodated along the furnace tube.

Using the manufacturing furnace configured as above, the silicon wafer 16
External diffusion of impurities into the silicon wafer 16
Is placed on a pedestal 17 made of quartz and housed in an inner quartz tube 11, and then, for example, B (boron) is supplied from one side of the quartz tube 11 and the silicon wafer 16 is supplied in an atmosphere containing B. Is heated to 900 ° C to 1000 ° C by the electric furnace 14. At this time, since at least one thermocouple 15 is set between the inner quartz tube 11 and the outer quartz tube 12, the quartz tube
The diffusion temperature within 11 can be monitored in real time. In addition, the temperature at a plurality of locations inside the furnace tube can be measured at one time.

It is desirable to select a thermocouple suitable for the temperature to be measured and the atmosphere used. Alternatively, the heater current may be directly controlled by the operation of the thermocouple.

In the above-mentioned embodiment, the case where the boron atom is diffused to form the p-type silicon is described. However, even when the P (phosphorus) is diffused to form the n-type silicon, the oxidizing gas is further supplied. It goes without saying that the present invention can be applied to an oxidation furnace that forms a silicon oxide film by using the above method.

〔The invention's effect〕

As described above, according to the manufacturing furnace of the present invention, since the thermocouple is accommodated between the inner quartz tube and the outer quartz tube of the double quartz tube structure, the wafer can be housed in the furnace. The temperature inside the quartz tube furnace can be monitored even in the processing state stored in.
Further, since the temperature under the processing state can be measured in real time in this manner, the temperature control becomes accurate, and therefore, the repetitiveness and uniformity of the processing can be improved. Further, since the thermocouple is detachably provided, the target thermocouple can be used by being applied to a plurality of furnaces.

[Brief description of drawings]

FIG. 1 is a partial perspective view for explaining the structure of a manufacturing furnace according to an embodiment of the present invention, FIG. 2 is a vertical sectional view showing an essential part of FIG. 1, and FIG. 3 is a drawing for explaining a conventional manufacturing furnace. Is. 10… Diffusion furnace, 11… Inner quartz tube, 12… Outer quartz tube, 13
… Soaking tube, 14… Electric furnace, 15… Thermocouple, 16… Silicon wafer, 17… Cradle.

Claims (1)

[Claims] 1. A quartz tube which is made of a hollow cylindrical body and which can accommodate a semiconductor wafer to be processed, and a soaking tube and a heater which are sequentially arranged outside the quartz tube so as to surround the quartz tube. A furnace for manufacturing a semiconductor device, wherein the quartz tube is heated by the heater to process the semiconductor wafer at a high temperature, and the quartz tube has a double tube structure in which the quartz tube is fitted loosely and the inner quartz tube is A furnace for manufacturing a semiconductor device, wherein at least one thermocouple for measuring an internal temperature of the inner quartz tube is provided between the outer quartz tube and the outer quartz tube.