JP2002110580A - Light irradiation type heat treating apparatus for wafers - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an apparatus which has a good reproducibility of the in-plane uniformity of the brightness over the upside of a substrate in a light irradiating and heating means for condensing through a condensing member lights radiated from a light source and for irradiating the substrate therewith, wherein a slight shift of the light source position relative to the condensing member has no influence on the brightness distribution over the substrate upside. SOLUTION: A light diffusion plate 40 is disposed between the upside of a substrate W held in a heat treating furnace 10 and a lamp house 22. A reflector 26 condenses lights radiated from the lamp 24 on a certain area and the diffusion plate diffuses the condensed lights to irradiate the substrate upside therewith.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a light irradiation type heat treatment apparatus for heat treating various substrates such as semiconductor wafers one by one by light irradiation, such as a lamp annealing apparatus.

[0002]

2. Description of the Related Art In recent years, in the manufacturing process of semiconductor devices, a single-wafer type lamp which heats and heat-treats a semiconductor wafer by using light irradiation from a lamp such as a halogen lamp or an arc lamp instead of a batch type electric furnace. Annealing devices are widely used in various processes. The lamp annealing apparatus includes a heat treatment furnace 10 having an opening 12 for loading and unloading a semiconductor wafer W, as shown in FIG.

[0003] At least the upper furnace wall of the heat treatment furnace 10 is
The light entrance window 14 is formed of a material having an infrared transmission property, for example, quartz glass. The opening 12 of the heat treatment furnace 10 is closed by a gate valve 16 so as to be openable and closable. Although not shown, a support arm for supporting the wafer W in a horizontal position is provided on the surface of the heat treatment furnace 10 facing the opening 12, and the wafer W before heat treatment is loaded from the alignment unit into the heat treatment furnace 10. A wafer transfer robot for carrying out the heat-treated wafer W from the heat treatment furnace 10 is provided.

A ring support guide 18 is provided inside the heat treatment furnace 10, and a wafer support ring 2 made of quartz glass is provided above the ring support guide 18.
0 is mounted in a horizontal position. Although not shown, a plurality of, for example, three support pins for supporting the wafer W by ascending and descending through the upper surface of the ring support guide 18 and abutting against the lower surface of the wafer W are provided. A wafer transfer mechanism provided with a drive unit for raising and lowering pins is provided. Then, the wafer W before the heat treatment is carried into the heat treatment furnace 10 while being supported by the support arm of the wafer transfer robot, and is transferred onto the raised support pins of the wafer transfer mechanism, and then the support pins are lowered. Thereby, it is placed on the wafer support ring 20 and is supported in a horizontal posture. Further, the wafer W after the heat treatment is lifted by raising the support pins.
After being floated from above the wafer support ring 20, the wafer is transferred from the support pins to the support arm of the wafer transfer robot, and is unloaded from the heat treatment furnace 10 by the wafer transfer robot.

A lamp house 22 is provided above the heat treatment furnace 10 so as to face the light entrance window 14. The lamp house 22 is provided with a plurality of lamps 24 such as a halogen lamp and an arc lamp, and a plurality of reflectors (reflecting plates) 26 provided for each lamp 24. The light emitted from each of the lamps 24 is efficiently condensed by the respective reflectors 26, passes through the light irradiation window 14, and irradiates the upper surface of the wafer W supported on the wafer support ring 20 in the heat treatment furnace 10. Is done.

Further, inside the heat treatment furnace 10, a plurality of gas blowing holes made of a material having an infrared transmission property, for example, quartz glass, are opposed to the upper surface of the wafer W supported on the wafer support ring 20. A gas flow distribution plate 28 with a perforation 30 is provided. This gas flow distribution plate 2
Between the light entrance window 8 and the light entrance window 14 is a gas introduction chamber 32 into which a processing gas such as nitrogen is introduced.
The flow path is connected to a processing gas supply source through a gas introduction path (not shown). Then, the processing gas supplied from the processing gas supply source and introduced into the gas introduction chamber 32 passes through the plurality of gas blowing holes 30 of the gas flow distribution plate 28 to the entire upper surface of the wafer W on the wafer support ring 20. It blows out evenly. On the other hand, an annular gas exhaust passage 34 is formed between the outer peripheral portion of the ring support guide 18 and the inner peripheral portion of the heat treatment furnace 10, and the gas exhaust passage 34 is connected to an exhaust port (not shown). Further, in order to keep the airtightness of the inside of the heat treatment furnace 10 high, O-rings 36 are respectively attached to a contact portion with the gate valve 16 and a joint portion with the light incident window 14.

In the lamp annealing apparatus having the above-described configuration, the wafer W is inserted into the heat treatment furnace 10 by the wafer transfer robot, and the wafer W is mounted on the wafer support ring 20 by the wafer transfer mechanism and supported in a horizontal posture. After that, the opening 12 of the heat treatment furnace 10 is
Is blocked by the heat treatment furnace 1 through the gas introduction passage.
0, the processing gas is introduced into the gas introduction chamber 32, and the processing gas is blown out from the gas introduction chamber 32 to the upper surface of the wafer W through the plurality of gas blowing holes 30 of the gas flow distribution plate 28,
The inside of the heat treatment furnace 10 is purged and exhausted through a gas exhaust passage. Then, the lamp house 22 is heated by a not-shown wafer temperature detecting device and a temperature controller so that the wafer W is heated to a desired temperature programmed in advance.
Is supplied to the plurality of lamps 24, and the wafer W is heated by light irradiation. When the heat treatment is completed, the wafer W
Is cooled to a desired temperature in the heat treatment furnace 10 and then carried out of the heat treatment furnace 10.

[0008]

When the light emitted from the lamp 24 is efficiently condensed by the reflector 26 and irradiated onto the upper surface of the wafer W as in the lamp annealing apparatus described above, energy efficiency is improved. Heat treatment of the wafer W can be performed. However, in the system in which the light from the lamp 24 is condensed by the reflector 26, the reflector 2
6, the position of the filament of the lamp 24 with respect to 6 changes only slightly, for example, by about 0.2 mm.
The illuminance distribution will be different. Therefore, if the lamp 24 is replaced, the in-plane uniformity of the illuminance on the upper surface of the wafer W cannot be reproduced, or the operation for reproducing the in-plane uniformity is extremely complicated. is there.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and a light irradiation heating means for condensing light radiated from a light source by a light condensing member and irradiating the light on a substrate is used for replacing a lamp. In a position where the position of the light source with respect to the light condensing member slightly changes, for example, there is no influence on the illuminance distribution on the upper surface of the substrate, and the substrate has good reproducibility of the in-plane uniformity of the illuminance on the upper surface of the substrate. It is an object of the present invention to provide a light irradiation type heat treatment apparatus.

[0010]

The invention according to claim 1 is
A heat treatment furnace in which at least an upper furnace wall is formed of a light-transmitting material and a substrate is carried therein and held in a horizontal position, and is disposed facing at least an upper surface of the substrate held in the heat treatment furnace, A light irradiation type heat treatment apparatus for a substrate, comprising: a light source and a light irradiation heating means comprising a light condensing member for condensing light emitted from the light source and irradiating the light to the substrate. It is characterized by comprising light diffusing means for making the irradiated light diffuse light.

According to a second aspect of the present invention, in the light irradiation type heat treatment apparatus of the first aspect, a plurality of quartz plates are provided inside the heat treatment furnace so as to face the upper surface of the substrate held in the heat treatment furnace. An apparatus provided with a gas flow distribution plate provided with gas blowing holes, wherein the light diffusion means is formed by forming the gas flow distribution plate from a quartz plate subjected to light diffusion processing. It is characterized by the following.

According to a third aspect of the present invention, in the light irradiation type heat treatment apparatus according to the first aspect, the upper furnace wall of the heat treatment furnace is formed by:
The light diffusing unit is characterized by being formed of a quartz plate subjected to light diffusion processing.

According to a fourth aspect of the present invention, in the light irradiation type heat treatment apparatus of the first aspect, a quartz plate subjected to light diffusion processing is interposed between the upper outer wall surface of the heat treatment furnace and the light irradiation heating means. The light diffusion means is used as the light diffusion means.

According to a fifth aspect of the present invention, in the light irradiation type heat treatment apparatus according to any one of the second to fourth aspects, the light diffusing means has a size equal to or larger than the substrate in plan view. It is characterized by.

According to a sixth aspect of the present invention, in the light irradiation type heat treatment apparatus of the first aspect, a light diffusion process is performed on a reflection surface of the reflection plate for condensing light from the light source, and the reflection plate itself is used as the reflection plate. It is characterized by light diffusion means.

According to a seventh aspect of the present invention, in the light irradiation type heat treatment apparatus according to the first aspect, the lamp tube for emitting light is subjected to light diffusion processing, and the lamp tube itself is connected to the light diffusion means. It is characterized by having.

In the light irradiation type heat treatment apparatus according to the first aspect of the present invention, the light emitted from the light source of the light irradiation heating means and condensed in a certain range by the light condensing member and irradiated to the substrate is irradiated with the light diffusion means. The light concentration is reduced while maintaining a certain light concentration. Therefore, variation in the illuminance distribution due to a change in the position of the light source with respect to the light-collecting member is smaller than when light emitted from the light source is condensed by the light-collecting member and is directly applied to the substrate surface. Therefore, even when the position of the light source with respect to the light condensing member is slightly changed when the lamp is replaced or the like, the illuminance distribution on the upper surface of the substrate is not affected, and the in-plane uniformity of the illuminance on the upper surface of the substrate can be easily improved. Can be reproduced.

In the light irradiation type heat treatment apparatus according to the second aspect of the invention, the light emitted from the light source of the light irradiation heating means and condensed in a certain range by the light condensing member is placed inside the heat treatment furnace on the upper surface of the substrate. The light is diffused by the quartz plate forming the gas flow distribution plate disposed opposite thereto, and the scattered light is applied to the substrate surface.

In the light irradiation type heat treatment apparatus according to the third aspect of the invention, the light emitted from the light source of the light irradiation heating means and condensed in a certain range by the light condensing member forms an upper furnace wall of the heat treatment furnace. The light is diffused by the quartz plate itself, and the diffused light is applied to the substrate surface.

In the light irradiation type heat treatment apparatus according to the fourth aspect of the invention, the light emitted from the light source of the light irradiation heating means and condensed in a certain range by the light condensing member is irradiated on the upper outer wall surface of the heat treatment furnace by the light irradiation. The light is diffused by a quartz plate interposed between the heating means and the diffused light is irradiated on the substrate surface.

In the light irradiation type heat treatment apparatus according to the fifth aspect of the invention, the light emitted from the light source of the light irradiation heating means and condensed in a certain range by the light condensing member is not directly irradiated on the substrate surface. The substrate surface is irradiated with the diffused light diffused by the light diffusing means. Therefore, the above operation of the invention according to claim 1 is optimally performed.

In the light irradiation type heat treatment apparatus according to the present invention, the light from the light source is condensed in a certain range by the reflector and diffused by the reflection surface itself of the reflector.
The light is applied to the substrate surface.

In the light irradiation type heat treatment apparatus according to the present invention, the light diffused by the lamp bulb itself is condensed in a certain range by the light condensing member, and the light is irradiated on the substrate surface.

[0024]

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

FIG. 1 is a schematic side sectional view showing a lamp annealing apparatus which is an example of an embodiment of the present invention and is a light irradiation type heat treatment apparatus. In FIG. 1 (the same applies to FIGS. 3 and 4 to be described later), the portions denoted by the same reference numerals as those used in FIG. 5 have the same functions as the respective constituent elements of the lamp annealing apparatus described based on FIG. And the same description will be omitted here.

In the lamp annealing apparatus shown in FIG. 1, the wafer W on the wafer support ring 20 is placed inside the heat treatment furnace 38.
A gas flow distribution plate 40 provided with a plurality of gas blowout holes 42 disposed opposite to the upper surface of the light diffusion plate 40 is made of a material having infrared transmittance, for example, quartz glass and subjected to light diffusion processing. It is constituted by a plate (diffuse plate). The light diffusion plate constituting the gas flow distribution plate 40 is processed, for example, by polishing the surface of a quartz plate to a rough surface having fine irregularities, or by processing such that the quartz plate contains many fine bubbles. It is produced by doing. Gas flow distribution plate 40
Is larger than the wafer W in plan view, but the gas flow distribution plate 4
0 is preferably equal to or larger than the wafer W in a plan view, and the entire surface of the gas flow distribution plate 40 is shown in FIG. It is more preferable to perform light diffusion processing.

In the lamp annealing apparatus having the structure shown in FIG. 1, the light emitted from each lamp 24 of the lamp house 22 and condensed in a certain range by each reflector 26 is placed in a heat treatment furnace 38 inside the wafer W. Is diffused by the gas flow distribution plate 40 disposed opposite the upper surface of the wafer W, and the scattered light is applied to the upper surface of the wafer W. For this reason, the light irradiated on the wafer W surface is decelerated while maintaining a certain degree of light condensing.
Compared with a conventional apparatus in which the light from 4 is condensed by the reflector 26 and irradiates the surface of the wafer W as it is, the variation in the illuminance distribution due to the change in the position of the filament of the lamp 24 with respect to the reflector 26 is reduced. Therefore, when the position of the lamp 24 with respect to the reflector 26 slightly changes when the lamp 24 is replaced, the wafer W
Without affecting the illuminance distribution on the upper surface of the wafer W, the in-plane uniformity of the illuminance on the upper surface of the wafer W can be easily reproduced.

FIG. 3 is a schematic side sectional view of a lamp annealing apparatus showing another embodiment of the present invention. In this apparatus, an upper furnace wall 46 itself of a heat treatment furnace 44 formed of a material having infrared transmittance, for example, quartz glass,
It is composed of a light diffusion plate subjected to light diffusion processing.
The device shown in FIG. 3 can provide exactly the same operation and effect as the device shown in FIG. FIG. 4 is a schematic sectional side view of a lamp annealing apparatus showing still another embodiment of the present invention. In this apparatus, a light diffusion plate 48 formed of an infrared transmitting material, for example, quartz glass and subjected to light diffusion processing is provided between the upper outer wall surface of the heat treatment furnace 10 and the lamp house 22.
Is attached and arranged on the light incident window 14 of the heat treatment furnace 10. The size of the light diffusing plate 48 is preferably equal to or larger than the wafer W in a plan view, and is more preferably a size that completely covers the entire surface of the wafer W. The same operation and effect as those of the apparatus shown in FIG. 1 can be obtained by the apparatus shown in FIG.

In each of the above embodiments, the upper surface of the wafer W supported on the wafer support ring 20 inside the heat treatment furnaces 38, 44 and 10 and the lamps disposed outside the heat treatment furnaces 38, 44 and 10 are described. The light emitted from the lamp 24 of the lamp house 22 and condensed by the reflector 26 is diffused by the quartz plate, and the diffused light is diffused by the wafer However, the light diffusing means for diffusing the light irradiated from the lamp house 22 onto the wafer W as the diffused light may be other than the above embodiment. For example, light reflection processing may be performed on the reflection surface of the reflector 26. In this case, the light from the lamp 24 is condensed to a certain area by the reflector 26 and is diffused by the reflection surface itself of the reflector 26,
The light is applied to the surface of the wafer W. Further, light diffusion processing may be performed on the bulb of the lamp 24.
In this case, light diffused by the lamp bulb itself of the lamp 24 is condensed in a certain range by the reflector 26, and the light is irradiated on the wafer W surface.

[0030]

When the light irradiation type heat treatment apparatus according to the first aspect of the present invention is used, the light emitted from the light source is condensed by the light condensing member and is condensed as compared with the case where the light is irradiated on the substrate surface as it is. Since the variation in the illuminance distribution due to the change in the position of the light source with respect to the member is reduced, when the position of the light source with respect to the light collecting member slightly changes at the time of lamp replacement,
The illuminance distribution on the upper surface of the substrate is not affected, and the reproducibility of the in-plane uniformity of the illuminance on the upper surface of the substrate is good.

According to the light irradiation type heat treatment apparatus of each of the inventions according to claims 2 to 4, the effects of the invention according to claim 1 can be reliably obtained.

In the light irradiation type heat treatment apparatus according to the fifth aspect of the present invention, the light emitted from the light source and condensed by the light condensing member is not directly irradiated on the substrate surface. The above effects are obtained to the maximum.

According to the light irradiation type heat treatment apparatus of each of the inventions according to the sixth and seventh aspects, the effects of the first aspect can be surely obtained. In this apparatus, there is no need to install a quartz plate subjected to light diffusion processing.

[Brief description of the drawings]

FIG. 1 is a schematic sectional side view of a lamp annealing apparatus as a light irradiation type heat treatment apparatus, showing an example of an embodiment of the present invention.

FIG. 2 is a plan view showing a size relationship between a wafer and a gas flow distribution plate having a light diffusion function, which is one of the components of the lamp annealing apparatus shown in FIG.

FIG. 3 is a schematic sectional side view of a lamp annealing apparatus showing another embodiment of the present invention.

FIG. 4 is a schematic sectional side view of a lamp annealing apparatus showing still another embodiment of the present invention.

FIG. 5 is a schematic side sectional view showing an example of a configuration of a conventional lamp annealing apparatus.

[Explanation of symbols]

 10, 38, 44 Heat treatment furnace 12 Heat treatment furnace opening 14, 46 Light entrance window 16 Gate valve 18 Ring support guide 20 Wafer support ring 22 Lamp house 24 Lamp 26 Reflector 28, 40 Gas flow distribution plate 30, 42 Gas outlet 32 Gas introduction chamber 34 Gas exhaust path 36 O-ring 48 Light diffusion plate W Semiconductor wafer

Claims (7)

[Claims] 1. A heat treatment furnace in which at least an upper furnace wall is formed of a light-transmissive material and a substrate is carried into the inside and held in a horizontal posture, and at least an upper surface of the substrate held in the heat treatment furnace is opposed to the heat treatment furnace. A light irradiation heating means comprising a light source and a light condensing member for condensing the light emitted from the light source and irradiating the light to the substrate. A light irradiation type heat treatment apparatus for a substrate, comprising: a light diffusing means for diffusing light emitted from the irradiation heating means to the substrate. 2. A gas flow distribution plate having a plurality of gas blowout holes formed in a quartz plate, facing a top surface of a substrate held in the heat treatment furnace, inside the heat treatment furnace. The light irradiation type heat treatment apparatus for a substrate according to claim 1, wherein the light diffusion means is a quartz plate subjected to light diffusion processing for forming the gas flow distribution plate. 3. A furnace plate on the upper side of the heat treatment furnace is formed of a quartz plate, and the light diffusing means is a quartz plate on which a light diffusion process for forming a furnace wall on the upper side of the heat treatment furnace is performed. 1
A light irradiation type heat treatment apparatus for a substrate as described above. 4. The light of a substrate according to claim 1, wherein said light diffusion means is a quartz plate which is interposed between an upper outer wall surface of said heat treatment furnace and said light irradiation heating means and subjected to light diffusion processing. Irradiation heat treatment equipment. 5. The light irradiation type heat treatment apparatus for a substrate according to claim 2, wherein the light diffusing means has a size equal to or larger than the substrate in plan view. 6. The light-irradiating method for a substrate according to claim 1, wherein the light-collecting member of the light-irradiating heating means is a reflector, and the light-diffusing means is a reflector having a reflecting surface subjected to light-diffusion processing. Heat treatment equipment. 7. The light-irradiation heat treatment apparatus for a substrate according to claim 1, wherein the light source of the light irradiation heating means is a lamp, and the light diffusion means is a lamp bulb of the lamp which has been subjected to light diffusion processing. .