JPS6236811A - Semiconductor manufacture device - Google Patents

Abstract

PURPOSE:To allow highly accurate temperature control with favorable heat- response by a method wherein the radiant light, which has a wavelength that corresponds to the temperature that is produced within a process tube when a wafer placed in the process tube is heated with a heating means, is detected with an optical fiber so as to measure the temperature. CONSTITUTION:A wafer within a process tube is heated with a heating means. The radiant light is detected with an optical fiber 12 and transmitted to a detector 14 through an optical fiber 13, and the light-receiving section in the detector 14 converts the radiant light into current and amplifies it. Further, the current is linearized to feed it as the temperature within the process tube 1. Thus, the heating means is controlled so that the temperature will be a set temperature.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a semiconductor manufacturing apparatus that manufactures semiconductor devices by high-temperature heat treatment at 400° C. or higher, and more particularly to a semiconductor manufacturing apparatus that controls the heat treatment temperature to a set temperature.

[Conventional technology]

FIG. 3 is a schematic diagram of a conventional semiconductor manufacturing apparatus for manufacturing semiconductor devices by high-temperature heat treatment such as oxidation or diffusion. In Figure 3, (1) is a process tube that accommodates the wafer (2) to be heat-treated and into which gas is fed, (3) is a quartz board on which the wafer (2) is placed, and (4) is a quartz board (3). ), the push rod (5) is for inserting and removing the wafer (
2) a plurality of resistance heaters, (6) a soaking zone provided between the process tube (1) and the resistance heater (5), and (7) a thermocouple.

By the way, in order to perform high-temperature heat treatment on the wafer (2) and manufacture uniform semiconductor devices, the process tube (1) is
It is necessary to control the temperature distribution within the range of ±1°C.

FIG. 4 is an explanatory diagram showing temperature measurements inside the process tube (1) that are periodically performed to control such temperature distribution. Note that in FIG. 4, parts that perform the same functions as those in FIG. 3 are denoted by the same reference numerals, and the explanation thereof will be omitted. In order to control the temperature distribution within the process tube +11 within a range of ±1°C, a plurality of thermocouples (9) protected by a protection tube (8) are periodically inserted into the process tube (1), and the temperature The profiler (10) measures the temperature distribution inside the process tube (1), and the control means controls the resistance heater (5) so that the temperature distribution is within a range of ±1°C. ) during the heat treatment, the temperature distribution inside the process tube (1) is ±1
The current flowing through the resistance heater (5) is controlled so that the temperature detected by the thermocouple (7) is reached when the resistance heater (5) is controlled to stay within the temperature range.

[Problem that the invention seeks to solve]

Conventional semiconductor manufacturing equipment controls the temperature inside the process tube (ill) based on the temperature detected by an electric thermocouple (7) located outside the process tube (1), which has poor thermal conductivity. There was a problem that the internal temperature could not be controlled.

Also, the process tube (1) on the wafer (2) insertion port side
As shown by curve A in Fig. 2, the temperature inside the wafer (2) increases immediately after inserting the wafer (2) into the process tube (1).
) is lower than the set temperature for heat treatment by about 30°C or more, and then gradually rises, but even after about 30 minutes, it is still about 5°C lower than the set temperature, and the temperature of the wafer (2) is uneven. There was a problem with this.

The present invention has been made to solve the above problems,
An object of the present invention is to provide a semiconductor manufacturing apparatus that can accurately control the temperature inside a process tube.

[Means for solving problems]

Therefore, in the present invention, a process tube containing a wafer to be subjected to high-temperature heat treatment, a heating means for heating the wafer in the process tube, and an optical fiber provided in the process tube to detect radiation light generated by heating the wafer are provided. A semiconductor manufacturing apparatus includes a control means for detecting the temperature inside the process tube based on the wavelength of the detected radiation light and controlling the temperature inside the process tube to a set temperature based on the detected temperature.

[For production]

The semiconductor manufacturing apparatus configured as described above heats the wafer within the process tube by the heating means. At this time, the radiant light generated by heating the wafer is detected by an optical fiber, the control means detects the temperature inside the process tube from the wavelength of the radiant light, and the heating means is adjusted so that the temperature inside the process tube becomes the set temperature. Control.

〔Example〕

Hereinafter, one embodiment of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 is a schematic diagram of a semiconductor manufacturing apparatus according to the present invention.

Note that in FIG. 1, parts that perform the same functions as those in FIG. 3 are denoted by the same reference numerals, and the explanation thereof will be omitted. (1
2) is a plurality of (3) optical fibers made of sapphire and detects the radiant light generated by the heat treatment of the wafer (2), and (13) is made of quartz and detects the radiant light detected by the optical fiber (12). An optical fiber that transmits (1
4) is a detector that converts radiated light into electric fi (W).

Next, the overall operation of the semiconductor manufacturing apparatus according to the present invention will be explained. When the wafer (2) in the process tube (1) is heated by the resistance heating heater (5), radiant light is generated. This radiation light is detected by an optical fiber (12) and transmitted to a detector (14) via an optical fiber (13). The detector (14) has a light receiving section that converts the radiated light into a current, amplifies it, linearizes this current, and outputs it as the temperature inside the process tube (1).

Note that it is well known as Blank's radiation law that the wavelength distribution of radiant light varies depending on the temperature inside the process tube (1). Therefore, the temperature inside the process tube (1) can be determined by detecting the wavelength of the radiant light. In addition, the wavelength of the radiant light can be detected using a circuit that combines two color filters and two photodiodes depending on the wavelength to be detected, or by integrating two photodiodes with peaks on the blue side and the infrared side. Color sensor or red, green, blue,
This is done using an amorphous integrated color sensor made up of color filters and photodiodes.

The control means (not shown) detects the temperature in the co-process tube (1) as described above and compares it with the set temperature, and controls the resistance heater ( 5) Increase or decrease the current flowing through. The temperature inside the process tube (1), which is controlled as described above, changes over time as shown by curve B shown in FIG. That is, the temperature inside the process tube (11) will temporarily drop due to the insertion of the wafer (2) into the process tube (11), but will reach the set temperature in about 15 minutes. (5), the wafer (2) may be heated by other heating means, such as a high-frequency heating device.In this case, the optical fiber (12) for detecting radiation light is heated by high-frequency heating, unlike a thermocouple. Since the temperature inside the process tube (1) is not affected by the electromagnetic field generated by the process tube (1), the temperature inside the process tube (1) can be detected accurately.

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〔Effect of the invention〕

As explained above, according to the present invention, radiation light having a wavelength corresponding to the temperature inside the process tube generated when a wafer placed inside the process tube is heated by the heating means is provided inside the process tube. Since the temperature inside the process tube is measured by detecting the temperature using an optical fiber, the temperature within the process tube can be effectively controlled with good thermal response and high accuracy.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram of a semiconductor manufacturing apparatus according to the present invention, FIG. 2 is an explanatory diagram of changes in moisture content in the process tube shown in FIGS. 1 and 3, and FIG. 3 is a diagram of a conventional semiconductor manufacturing apparatus. The schematic diagram, FIG. 4, is an explanatory diagram of temperature measurement in a conventional semiconductor manufacturing apparatus. In each figure, 1 is a process tube, 2 is a wafer, 3 is a quartz board, 4 is a push rod, 5 is a resistance heater, 6 is a soaking zone, 12, 13 is an optical fiber, and 14 is a detector.

Claims (4)

[Claims] (1) A process tube that accommodates a wafer to be subjected to high-temperature heat treatment, a heating means provided around the process tube to heat the wafer, and a heating means provided in the front process tube to heat the wafer by heating the wafer. A detection optical fiber and a control means for detecting the temperature inside the process tube based on the wavelength of the detected radiation light and controlling the temperature inside the process tube to a set temperature based on the detected temperature. A semiconductor manufacturing device characterized by: (2) The semiconductor manufacturing apparatus according to claim 1, wherein the process tube is provided with the heating means surrounding it via a soaking zone. (3) The semiconductor manufacturing apparatus according to claim 1, wherein the heating means is a resistance heater. (4) The semiconductor manufacturing apparatus according to claim 1, wherein the optical fiber is made of sapphire at least at a portion located inside the process tube.