JPH02166728A - Semiconductor heat treating apparatus and method of controlling the apparatus - Google Patents

Abstract

PURPOSE:To make it possible to perform accurate heat treatment by directly measuring the temperature of a wafer or the vicinity of the wafer with non- contact type thermometer, and controlling the temperature of a heat treating apparatus. CONSTITUTION:The temperature of each temperature measuring part 19 in the vicinity of a wafer 1 is directly measured with a non-contact type thermometer 12. In this way, the temperature difference due to the separation between the vicinity of the wafer and an inner thermocouple 3, the separation being a problem in a heat treating device, and the temperature difference due to heat conductivity between the wafer 1 and the inner thermocouple and due to the difference in absorption of radiated heat are eliminated. Therefore, the actual temperature of the wafer 1 can be controlled at a preset temperature. The uniformity in the characteristics of the devices between batches is improved in the heat treating apparatus provided with this temperature measuring method, and the yield rate is remarkably improved.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a heat treatment apparatus used in the semiconductor industry;
In particular, the present invention relates to a method for measuring the temperature of a wafer or the vicinity of a wafer, a boat for arranging wafers, and a method for controlling temperature in a temperature rising/lowering state.

Conventional technology (1) Conventional heat treatment equipment is as shown in Figure 4.
The temperature near the wafer 1 is measured by an internal thermocouple 3 installed in the tube 2, and the temperature near the heater 4 is measured by an external thermocouple 5 installed between the heater 4 and the tube 2. The heater output 6 during heat treatment is controlled by the temperature measured by the external thermocouple 5, and the temperature of the external thermocouple 5 at this time is the temperature difference between the internal thermocouple 3 and the external thermocouple 5 measured in advance. Use the temperature corrected by FIG. 4 is an explanatory diagram of a conventional heat treatment apparatus, in which 1 is a wafer, 2 is a tube, 3 is an internal thermocouple, 4 is a heater, 5 is an external thermocouple, 6
indicates the heater output, 7 indicates the boat, 8 indicates the gas supply device, 9 indicates the temperature controller, and 10 indicates the shutter.

(2) A conventional boat 7 for arranging wafers 1 and inserting them into a tube 2 is as shown in FIG. 5, and is made of a material such as quartz, and has grooves 11 for fixing the wafers 1. When measuring the temperature of the wafers 1 arranged on the boat 7 from the gas supply device 8 side of the tube 2 using the non-contact thermometer 12, the temperature of the wafer 1 closest to the gas supply device 8 of the wafers 1 arranged in the arrangement is measured. Measure. Figure 5 shows a conventional boat 7
In this explanatory diagram, 11 indicates a groove, and 12 indicates a non-contact type thermometer.

(3) The temperature control method in the temperature rising/lowering state 15 of the conventional heat treatment equipment is as shown in Fig. 6(a).The internal thermocouple 3 and the external thermocouple are The heater output 6 in the temperature increase/decrease state 15 is controlled based on the temperature of the external thermocouple 5 whose temperature difference with the thermocouple 5 has been corrected.

Alternatively, as shown in FIG. 6(b), the heater output 6 in the temperature rising/lowering state 15 is controlled based on an appropriate temperature between the temperature of the external thermocouple 5 and the temperature of the internal thermocouple 3. FIGS. 6(a) and 6(b) are explanatory diagrams of a temperature control method during temperature raising and lowering of a conventional heat treatment apparatus, in which 13 is a low temperature state a, 14 is a low temperature state b, 15 is a temperature raising and lowering state, and 16 is an external thermoelectric 17 is the temperature indicated by the internal thermocouple, and 18 is the set temperature.

Problems to be Solved by the Invention (1) As shown in FIG. 4, in the conventional heat treatment apparatus, the temperature near the wafer 1 is measured by an internal thermocouple 3 installed near the boat 7 in the tube 2. Therefore, the distance between the wafer 1 and the internal thermocouple 3 is quite large, and a large difference occurs between the temperature of the wafer 1 and the temperature indicated by the internal thermocouple 3.

In addition, since the thermal conductivity and absorption coefficient of radiant heat of the materials of the wafer 1 (semiconductor) and the internal thermocouple 3 (platinum-rhodium, etc.) are different, there is a large difference between the temperature of the wafer 1 and the temperature indicated by the internal thermocouple 3. occurs. For these reasons, the temperature of the wafer 1 cannot be measured accurately.

(2) When trying to measure the temperature of the wafer 1 with the non-contact thermometer 12, in the conventional boat 7 as shown in FIG.
Only the temperature of the wafer 1 closest to the non-contact thermometer 12 lined up on the boat 7 can be measured. Therefore, it is not possible to measure the temperature of the wafers 1 at the bottom of the boat 7 at the same time.

(3) The temperature control method in the temperature rising/lowering state 15 of the conventional heat treatment equipment is as shown in Fig. 6(a).The internal thermocouple 3 and the external thermocouple are Based on the temperature of the external thermocouple 5 corrected for the temperature difference with the thermocouple 5, the heater output 6 in the temperature rise/decrease mode 'l'i 15 is controlled. In the case of this temperature control method, the internal thermocouple 3 (i.e., near the wafer 1) and the external thermocouple 5 (i.e., near the heater 4) have significantly different temperature increase/decrease rates. The temperature of the external thermocouple 5 is significantly different, and even if the external thermocouple 5 follows the set temperature 18 in the temperature rising/lowering state 15, the temperature of the internal thermocouple 3 is the set temperature 1.
Thick (off) from 8.

Furthermore, as shown in FIG. 6(b), there is also a method of controlling the heater output 6 in the temperature rising/lowering state 15 based on an appropriate temperature between the temperature of the external thermocouple 5 and the temperature of the internal thermocouple 3. .

In this temperature il + control method, the temperature difference between the temperature of the internal thermocouple 3 and the set temperature 18 is smaller than in the temperature control method shown in FIG. 6(a), but the response speed of the temperature of the internal thermocouple 3 to the set temperature 18 is smaller. Since the temperature is significantly slower than that of the external thermocouple 5, there is a difference in temperature increase/decrease start and end times.

Means for Solving the Problems The present invention is a semiconductor heat treatment apparatus characterized in that a boat of a batch processing type heat treatment apparatus has a measurement point made of the same material as the wafer at one place or at the bottom. .

The temperature near the working wafer is measured with high precision, enabling accurate heat treatment.

Example (Example 1) In the first example of the present invention, as shown in FIG. 1, the temperature of a temperature measurement point 19 near the wafer l is directly measured with a non-contact thermometer 12. An explanatory diagram of the heat treatment apparatus of the present invention,
19 is a temperature measuring point, 20 is a rod, and 21 is a strip of the wafer.

By actually applying the temperature measuring method of the present invention (directly measuring the temperature of the wafer 1 with a non-contact thermometer 12) as shown in FIG. The actual temperature of the wafer 1 is eliminated because there is no temperature difference due to the distance between the wafer 1 and the internal thermocouple 3, or a difference in thermal conductivity or radiant heat absorption between the wafer 1 and the internal thermocouple 3. could be controlled according to the set temperature 18.

Further, when a device was prototyped by applying the heat treatment apparatus equipped with the temperature measuring method of the present invention to an actual process, the uniformity of device characteristics between batches was improved and the yield was significantly improved.

(Embodiment 2) In a second embodiment of the present invention, as shown in FIG. 2, a humidity measuring point 19 made of the same material as the wafer 1 is provided at an arbitrary location on the boat 7. FIG. 2 is an explanatory diagram of the boat 7 of the present invention.

The boat 7 of the present invention as shown in FIG. By using the heat treatment device to measure the temperature at any location on the boat 7, temperature control with extremely high uniformity of temperature within the boat 7 could be achieved.

Further, when a device was prototyped by applying the heat treatment apparatus equipped with the boat 7 of the present invention to an actual process, the uniformity of device characteristics within a batch was improved and the yield was significantly improved.

(Embodiment 3) In the third embodiment of the present invention, as shown in FIG. The heater output 6 is controlled in the temperature increasing/decreasing state 15 during heat treatment. Third
The figure is an explanatory diagram of the temperature control method in state 15 of raising and lowering the temperature of the heat treatment apparatus of the present invention.

As shown in FIG. 3, the temperature control method in the temperature rising/lowering state of the present invention (during heat treatment based on the control data of the heater output 6 to bring the temperature rising/lowering rate near the wafer 1 to a predetermined value measured in advance) The temperature difference between the temperature 17 indicated by the internal thermocouple and the set temperature 18 in the temperature rising/lowering state 15 is reduced by
The actual temperature increase/decrease rate near the wafer 1 could be controlled to the set value.

With the above-described configuration, it is possible to accurately measure the actual temperature near the wafer, and accurate temperature control can be performed based on this output.

Further, when a device was prototyped by applying the heat treatment apparatus equipped with the temperature control method of the present invention to an actual process, the uniformity between batches, which is a characteristic of the device, was improved and the yield was significantly improved.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view of the schematic structure of the semiconductor heat treatment apparatus of the present invention, FIG. 2 is a cross-sectional view of the schematic structure of the boat of the present invention, and FIG. figure,
FIG. 4 is a cross-sectional view of the schematic structure of a conventional semiconductor heat treatment apparatus.
FIG. 5 is a sectional view of a schematic structure of a conventional boat, and FIG. 6 is an explanatory diagram of an embodiment of a conventional temperature control method in a temperature increasing/decreasing state. l...Wafer, 2...Tube, 3.
...Internal thermocouple, 4...Heater, 5.
...External thermocouple, 6...Heater output,
7...Boat, 8...Gas supply device,
9...Temperature controller, 10...
Shutter 11... Groove, 12... Non-contact thermometer, 13... Fixed temperature state a, 14...
... Constant temperature state b, 15 ... Temperature rising and falling state, 1
6...Temperature indicated by external thermocouple, 17...
・Temperature indicated by internal thermocouple, 18... Set temperature,
19...Temperature measurement point, 20...Bar, 21
...Strips of wafer. Name of agent: Patent attorney Shigetaka Awano and one other person court district

Claims (3)

[Claims] (1) A semiconductor heat treatment apparatus that is a batch processing type heat treatment apparatus and is characterized in that the temperature of the heat treatment apparatus is controlled by directly measuring the temperature of the wafer or the vicinity of the wafer using a non-contact thermometer. (2) A semiconductor heat treatment device characterized by having one or several temperature measurement points made of the same material as the wafer in a boat of a batch processing type heat treatment device. (3) In a temperature control method for heating and cooling the heat treatment equipment, the temperature rise and fall during heat treatment is controlled based on control data for the heater output to bring the temperature rise and fall rate of the wafer or the vicinity of the wafer to a predetermined value, which has been measured in advance. 1. A method of controlling a semiconductor heat treatment apparatus, the method comprising: controlling a heater output under a certain condition.