JPH05114570A - Photoirradiation heating system - Google Patents

Abstract

PURPOSE:To provide the title photoirradiation heating system eliminating the pre-heating step of semiconductor wafer, further averting the uneven heating effect. CONSTITUTION:The title photoirradiation heating system is arranged with multiple CW arc lamps 7 on the parallel plane with a wafer W as well as the variable resistors 15 respectively fluctuating the ratios of power fed to respective CW arc lamps 7. In such a constitution, the resistance value of the variable resistors 15 is set up corresponding to the irradiation efficiency of the CW arc lamps 7 top perform the photoirradiation heating process.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a semiconductor wafer (hereinafter,
In particular, the present invention relates to a device for heating and irradiating a wafer with light in order to stabilize the structure and physical properties of the substance by heating the wafer to a high temperature in a short time and then slowly cooling it, or by heat-treating it at a high temperature for a long time. ..

[0002]

2. Description of the Related Art Light irradiation heat treatment in a semiconductor manufacturing process is performed over a wide range such as activation of an ion implantation layer, formation of a metal silicide, formation of a thermal oxide film as a post-treatment of ion implantation. In both cases, the wafer is heated at a high temperature, but a light irradiation heating device using a halogen lamp or a high-intensity xenon lamp as a heating means has been attracting attention in order to speed up the process.

As a conventional light irradiation heating device, a device having two forms will be taken as an example. (1) A device for arranging a plurality of flash discharge lamps in a plane that is parallel to and close to the surface of a wafer carried into a processing furnace and irradiates the wafer with pulsed light to heat the wafer. 2) One CW arc lamp (CW: continuous wav) above the wafer loaded into the processing furnace.
e-Continuous oscillation), and irradiates the wafer with light for a required time to heat it.

[0004]

However, each of the conventional devices listed above has the following drawbacks. Since the device described in (1) uses pulsed light,
The wafer cannot be heated to a high temperature with a single flash, so a mechanism for preheating to about 400 degrees Celsius is required. Therefore, the configuration of the device becomes complicated, and
The cost of the device is increased by separately installing a heater for preheating. Since the device described in (2) uses continuous light,
Although it does not require the above preheating, it is difficult to uniformly heat the surface of the wafer with one CW arc lamp.
Non-uniformity of in-plane temperature distribution is likely to occur.

The present invention has been made in view of such circumstances, and an object of the present invention is to provide a light irradiation and heating device which solves the above-mentioned drawbacks.

[0006]

The present invention has the following constitution in order to achieve such an object. That is, the light irradiation heating apparatus of the present invention has a plurality of continuous discharge lamps (CW arc lamps) arranged in a plane parallel to the semiconductor wafer which is the object to be processed, and the temperature distribution of the semiconductor wafer is uniform. Based on the detection signal from the temperature setting means for detecting the temperature of the semiconductor wafer, the power setting means for arbitrarily setting the ratio of the power supplied to each of the continuous discharge lamps, Control means for controlling the power setting means so that the temperature of the semiconductor wafer becomes a target temperature.

[0007]

The light irradiation heat treatment according to the constitution of the present invention is performed as follows. First, the power setting means is used to set the ratio of the power supplied to each continuous discharge lamp so that the temperature distribution of the semiconductor wafer becomes uniform. Next, the continuous discharge lamps are turned on all at once to irradiate the semiconductor wafer with continuous light for heating. The temperature detecting means detects the temperature of the semiconductor wafer to be heated and sends a detection signal to the control means. The control means controls the power setting means to adjust the power supplied to each continuous discharge lamp so that the detected temperature of the semiconductor wafer becomes the target temperature. At this time, since the ratio of the power supplied to each continuous discharge lamp is set by the power setting means,
The temperature distribution of the semiconductor wafer approaches the target temperature while maintaining a uniform temperature distribution. Further, since a continuous discharge lamp is used, there is no need for preheating.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a cross-sectional view of a light irradiation and heating device according to this embodiment. A wafer W, which is an object to be processed, is supported by the susceptor 1 and carried into a flat quartz chamber 2 made of quartz. The susceptor 1 is joined to a lid 3 which is movable toward and away from the entrance of the quartz chamber 2, and the entrance of the quartz chamber 2 is sealed by the lid 3 at the same time when the wafer W is loaded. .. Wall 4 facing the inlet of the quartz chamber 2
A gas nozzle 5 for introducing an inert gas (for example, nitrogen gas), oxygen gas, and other required gas into the quartz chamber 2 is attached to this. A dispersion ring 6 for dispersing a gas such as an inert gas inside the quartz chamber 2 is provided at the tip of the gas nozzle 5.

A wafer W is provided outside the quartz chamber 2.
A plurality of continuous discharge lamps 7 (hereinafter referred to as CW arc lamps) are arranged in a plane parallel to the surface of the. A reflector 8 is attached to the back side of the CW arc lamp 7 and the back side of the wafer W sandwiching the quartz chamber 2 so that the heat radiation from the CW arc lamp 7 is directed toward both the front and back sides of the wafer W. Has been done. Quartz chamber 2
On the lower wall surface, a hollow cylindrical lead-out portion 9 protruding downward is formed just below the wafer W to be housed. The lead-out portion 9 passes through the reflection plate 8 and leads out to the outside of the device, and a radiation thermometer 12 is provided at the lead-out end. At the front of the radiation thermometer 12, a window body 10 that shuts off the atmosphere inside and outside the furnace is attached.

Since the CW arc lamp 7 emits light in the wavelength range of 1500 nm or less, the radiation thermometer 12 is
For example, by using a thermopile having a photometric characteristic near 5500 to 10000 nm, the CW arc lamp 7
Only the light emitted from the wafer W is guided to the radiation thermometer 12 and the temperature of the wafer W is detected.

The output of the radiation thermometer 12 is given to the power supply control unit 13, and the power supply control unit 13 is individually provided for each CW arc lamp 7 so that the temperature of the wafer W reaches a preset target temperature. The outputs of the plurality of power supply units 14 are simultaneously feedback-controlled. In this way, the light irradiation and heat treatment of the wafer W is performed, but the temperature distribution on the surface of the wafer W is not necessarily uniform only by this. For example, each C
Irradiation efficiency of the W arc lamp 7 has variations, and no matter how the shape of the reflection plate 8 is modified, the intensity of light irradiation at the central portion and the end portion inside the quartz chamber 2 can be completely adjusted. Since it is extremely difficult to make the temperature uniform, an undesired phenomenon that the in-plane temperature distribution of the wafer W is non-uniform occurs.

Therefore, in this embodiment, a variable resistor 15 is provided between each power supply unit 14 and the power supply control unit 13 as power setting means. The variable resistor 15 varies the value of the control signal output from the power supply control unit 13 and sets it to a value corresponding to each power supply unit 14 (that is, corresponding to each CW arc lamp 7).
This setting method will be described below.

First, a dummy wafer S equivalent to a wafer W as an object to be processed is supported on a susceptor 1 and a quartz chamber 2 is provided.
Carry it inside. The power supply control unit 13 controls each power supply unit 14 so that the target temperature of the light irradiation heating process is reached, and the dummy wafer S is heated for a required time. At this time, the resistance value of the variable resistor 15 is set to a constant arbitrary resistance value or set to “zero”. The dummy wafer S after the heat treatment is unloaded from the quartz chamber 2 and the thickness of the oxide film formed on the dummy wafer S is measured in places.

Each CW arc lamp 7 is used as a measuring point.
An example is a location corresponding to the installation position of.
This is because if the irradiation efficiency of each CW arc lamp 7 varies, the thickness of the oxide film becomes non-uniform at the location corresponding to the installation position of each CW arc lamp 7. That is, the correlation between the nonuniformity of the thickness of the oxide film and the variation in the irradiation efficiency of each CW arc lamp 7 is obtained. Then, the value of the control signal supplied from the power supply control unit 13 to the power supply unit 14 of each CW arc lamp 7 is changed by the variable resistor 15 so that the thickness of the oxide film becomes uniform. The resistance value of the variable resistor 15 set here is fixed, and then the wafer W, which is an object to be processed, is subjected to heat treatment.

In order that the temperature of the wafer W reaches the target temperature,
The signal value of the feedback control output from the power supply control unit 13 is uniformly sent to the power supply unit 14 of each CW arc lamp 7, but is actually applied to each power supply unit 14 through the variable resistor 15. The value of the signal is the value of each C as set above.
It is converted into a value according to the irradiation efficiency of the W arc lamp 7. Thus, the wafer W is heated to the target temperature while keeping the temperature distribution on the surface of the wafer W constant.

As the power setting means, instead of the variable resistor 15 described above, a computer program may be used to set the value of the control signal. That is, a coefficient value for changing the value of the control signal given to each power supply unit 14 is set by a program so that the thickness of the oxide film formed on the dummy wafer S becomes uniform.

Further, each CW arc lamp 7 is based on the non-uniformity of the thickness of the oxide film of the dummy wafer S as described above.
Rather than obtaining the difference in the heat radiation of the dummy wafer S, thermocouples are attached to the surface of the dummy wafer S everywhere to monitor the temperature distribution on the surface of the dummy wafer S, and the resistance of each variable resistor 15 is adjusted so as to eliminate the variation in the temperature distribution. You may make it set a value.

Further, instead of mounting a plurality of CW arc lamps 7 facing the surface of the wafer W as shown in the above embodiment, a plurality of CW arc lamps 7 are mounted on each of the planes facing the front and back surfaces of the wafer W. Alternatively, the CW arc lamp 7 may be provided. Further, as shown in FIG. 2, only one power supply unit 14 for supplying electric power to each CW arc lamp 7 is provided, and a variable resistor 15 is provided between each CW arc lamp 7 and the power supply unit 14. You can

[0019]

As is apparent from the above description, according to the light irradiation and heating apparatus of the present invention, the power supplied to each continuous discharge lamp is controlled so that the temperature of the semiconductor wafer becomes the target temperature. Since the ratio of the power supplied to each continuous discharge lamp is set so that the temperature distribution of the semiconductor wafer becomes uniform, the semiconductor wafer can be heated to the target temperature under the uniform temperature distribution. It is possible to perform a light irradiation heat treatment with a uniform in-plane temperature distribution. Further, since a continuous discharge lamp is used, there is no need for preheating.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a schematic configuration of a light irradiation heating device according to an embodiment of the present invention.

FIG. 2 is a diagram showing another configuration example of the light irradiation heating device.

FIG.

[Explanation of symbols]

 7 ... CW arc lamp 13 ... Power supply control unit 14 ... Power supply unit 15 ... Variable resistor W ... Wafer

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[Procedure amendment]

[Submission date] October 13, 1992

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be corrected] Brief description of the drawing

[Correction method] Change

[Correction content]

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a schematic configuration of a light irradiation heating device according to an embodiment of the present invention.

FIG. 2 is a diagram showing another configuration example of the light irradiation heating device.

Claims (1)

[Claims] 1. A plurality of continuous discharge lamps (CW arc lamps) arranged in a plane parallel to a semiconductor wafer to be processed, and each of the semiconductor wafers so that the temperature distribution of the semiconductor wafer becomes uniform. A power setting unit that arbitrarily sets the ratio of the power supplied to the continuous discharge lamp, a temperature detection unit that detects the temperature of the semiconductor wafer, and a temperature of the semiconductor wafer based on a detection signal from the temperature detection unit. A light irradiation heating device, comprising: a control unit that controls the power setting unit so that the target temperature is reached.