JPH0533143A - Method for controlling temperature of atmospheric pressure cvd device - Google Patents

Abstract

PURPOSE:To rapidly control the temp. in accordance with the deviation of the measured temp. on a tray and change with time. CONSTITUTION:An IR radiation thermometer 14 or a contacting surface thermometer is set on a tray 2 in place of a thermocouple, the temp. on the tray is measured by the thermometer, the signal is inputted to a temp. controller 11 and a microcomputer 15, and the surface temp. of the tray 2 is controlled. Since the surface temp. of the tray 2 is measured, temp. deviation is eliminated, the temp. is controlled in accordance with the change with time by controlling the temp. with the microcomputer, 15 and a chemical vapor growth film is obtained with the thickness and quality stabilized.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a temperature control method for an atmospheric pressure CVD apparatus, and more particularly to a temperature control method using a microcomputer equipped with an infrared radiation thermometer or a surface thermometer.

[0002]

2. Description of the Related Art As shown in FIG. 3, a heater unit of a conventional atmospheric pressure CVD apparatus includes a quartz plate 4 on a heater block 5 having a heater wire incorporated therein and a ceramic fiber for the purpose of heat insulation downward. 9, a heater mount 6 on which a heater block is placed, a thermocouple 10 for sensing the temperature of the heater block 5, and a thermocouple 10.
It has a temperature controller 11 which controls the temperature in response to the detection of

Next, the operation will be described. The thermocouple 10 installed between the heater blocks 5 senses the temperature of the heater wire and turns on and off the thyristor (SCR) 12 by the temperature controller 11 to control the temperature.

[0004]

This conventional atmospheric pressure CVD
In the temperature control method of the device, the temperature measurement (measured value 600 ° C) and temperature control are performed by the thermocouple installed between the quartz plate and the heater block. There is a problem in that there is a temperature shift of about 200 ° C. from the temperature measured by the thermometer or the contact surface thermometer ... Measured value 400 ° C.).

Further, while the chemical vapor deposition (CVD) is being performed on the wafer on the tray, the chemical vapor grown oxide film is also formed on the tray. The thicker the oxide film is, the lower the surface temperature on the tray tends to be.However, the thermocouple installed between the quartz plate and the heater block cannot detect this tendency, and quick temperature control and temperature There was a problem that it could not be controlled.

The object of the present invention is to reduce the temperature deviation between the measurement temperature and the tray surface temperature, to prevent the surface temperature from decreasing with the passage of time, to enable rapid temperature control, and to improve the chemical vapor deposition film batch. It is an object of the present invention to provide a temperature control method for an atmospheric pressure CVD apparatus capable of forming a stable film by reducing the variation in the thickness between films and eliminating the change in film quality due to temperature change.

[0007]

The temperature control method for an atmospheric pressure CVD apparatus according to the present invention comprises an infrared radiation thermometer or a contact surface thermometer for actually measuring the surface temperature on a tray, and a temperature signal measured by the thermometer. It is characterized by comprising a microcomputer control circuit and a temperature controller for controlling the surface temperature on the tray based on the above.

[0008]

The present invention will be described below with reference to the drawings. FIG. 1 is a schematic diagram for explaining a temperature control method for an atmospheric pressure CVD apparatus according to an embodiment of the present invention. The heater unit section has a heater block 5 provided with a heater wire for heating the wafer 1 on the tray 2, a quartz plate 4 for uniformly transmitting heat, and a quartz plate 4 for pressing the quartz plate 4 as in the conventional atmospheric pressure CVD apparatus. A quartz holder 7 for supporting the heater block 5, a heater stand 6 for supporting the heater block 5, a ceramic fiber 9 as a heat insulating material, a heater height adjusting screw 8 for adjusting the height of the heater, a water cooling jacket 3 for cooling the heater block 5 and the like. ing. Further, the heater block 5 is connected to a heater power supply 13 via a thyristor (SCR) 12.

The surface temperature on the tray 2 is measured by a non-contact infrared radiation thermometer 14, the signal is input to the temperature controller 11, and then the microcomputer 15 equipped with a CPU, a memory and an I / O port. In the output microcomputer 15, the thyristor (SCR) while outputting the electromotive force corresponding to the temperature setting value.
This is a method of controlling temperature by turning on and off 12.

FIG. 2 shows an atmospheric pressure CVD according to another embodiment of the present invention.
It is the schematic of the temperature control method of an apparatus. The heater unit has the same specifications as in the first embodiment. The difference from Example 1 is that
A contact type surface thermometer 16 is used as a thermometer for measuring the surface temperature on the tray 2. Before loading the wafer 1, the surface thermometer 16 is brought into contact with the tray 2 to measure the temperature, and the signal is input to the temperature controller 11 and the microcomputer 15 to control the temperature. In this case, when the wafer 1 is loaded on the tray 2, there is a drawback that temperature measurement and temperature control cannot be performed. There is no problem because it can cope with the time-dependent change of decrease. Further, when the height of the surface thermometer 16 is adjusted and when the surface thermometer 16 is not used, it is kept above the tray 2 by the height adjustment stand 17.

[0011]

As described above, according to the present invention, the surface temperature on the tray is measured by using the infrared radiation thermometer or the contact type surface thermometer, and the signal is sent to the temperature controller and the microcomputer control circuit. Since the temperature is controlled by inputting, there is no temperature deviation of about 200 ° C of the tray surface temperature, and it is possible to cope with the change over time that the surface temperature decreases as the oxide film is formed on the tray. Therefore, the temperature can be quickly controlled.

As a result, in the conventional atmospheric pressure CVD apparatus, the batch-to-batch film thickness variation of the oxide film (chemical vapor deposition film), which is caused by the decrease of the surface temperature on the tray with the passage of time, is significantly increased. It also has the effect of reducing the size, eliminating the change in film quality due to temperature changes, and forming a stable oxide film.

[Brief description of drawings]

FIG. 1 is a schematic diagram showing the configuration of an embodiment of the present invention,
(A) is a heater part and a temperature control part, (b) is a circuit diagram.

FIG. 2 is a schematic diagram showing the configuration of another embodiment of the present invention,
(A) is a heater part and a temperature control part, (b) is a circuit diagram.

3A and 3B are schematic diagrams showing a configuration of a temperature control method of a conventional atmospheric pressure CVD apparatus, wherein FIG. 3A is a heater section, FIG. 3B is a temperature control section, and FIG.

[Explanation of symbols]

 1 Wafer 2 Tray 3 Water-cooling jacket 4 Quartz plate 5 Heater block 6 Heater stand 7 Quartz holder 8 Heater height adjusting screw 9 Ceramic fiber 10 Thermocouple 11 Temperature controller 12 Thyristor (SCR) 13 Heater power supply 14 Infrared radiation thermometer 15 Microcomputer 16 Contact surface thermometer 17 Contact surface thermometer Height adjustment stand

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Office reference number FI technical display location H01L 21/31 F 8518-4M

Claims (1)

Claim: What is claimed is: 1. An infrared radiation thermometer or a contact surface thermometer for actually measuring the surface temperature on a tray, and the surface temperature on the tray is controlled based on a temperature signal measured by the thermometer. A temperature control method for an atmospheric pressure CVD apparatus comprising a microcomputer control circuit and a temperature controller.