JPH09289175A - Light irradiation thermal treatment device of substrate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent material evaporated from a substrate from being attached to the ceiling inner wall of an oven in a thermal treatment, by a method wherein a light transmitting member larger than the substrate is fitted to a substrate support means so as to be located between the upside of the substrate and the ceiling inner wall of the oven. SOLUTION: Three support rods 32 are fixed to the upside of a suscepter 18, and a light transmitting flat plate 34 is supported on the three support rods 32 in a detachable manner. The light transmitting flat plate 34 is transparent to infrared rays and equal to or larger than a semiconductor substrate W in size. The light transmitting flat plate 34 is interposed between the upside of the substrate W supported by the suscepter 18 and the ceiling inner wall of an oven 10. In a thermal treatment, material evaporated from the substrate W is attached to the underside of the light transmitting flat plate 34 as restrained from adhering to the ceiling inner wall of the oven 10. When the light transmitting flat plate 34 gets clouded, an oven gate block 14 is opened, the light transmitting flat plate 34 is taken out together with the suscepter 18, dismounted from the support rods 32 and replaced with a new clean one.

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 A light irradiation type heat treatment apparatus for heating a substrate, for example, a semiconductor wafer by light irradiation has a structure shown in a schematic side sectional view in FIG. That is, this light irradiation type heat treatment apparatus includes a heat treatment furnace 10 having an opening 12 on the front side for loading and unloading the semiconductor wafer W. The furnace wall of the heat treatment furnace 10 is formed of, for example, quartz glass having infrared transparency. On the opening 12 side of the heat treatment furnace 10, a furnace port block 14 is provided so as to be connected to the heat treatment furnace 10. The front opening of the furnace port block 14 is closed by a movable flange 16 so as to be openable and closable. A susceptor 18 that horizontally supports the wafer W is integrally fixed to the inner surface side of the movable flange 16, and the movable flange 16 reciprocates in the horizontal direction to move the wafer W supported by the susceptor 18. Are carried in and out of the heat treatment furnace 10. Then, the movable flange 16 moves toward the heat treatment furnace 10 side and comes into contact with the furnace port block 14, thereby closing the front opening of the furnace port block 14 and at the same time, the susceptor 1
The wafer W supported by 8 is arranged at a predetermined position in the heat treatment furnace 10.

In the vertical direction of the heat treatment furnace 10, a light irradiation light source 20 composed of a lamp group such as a halogen lamp and a xenon lamp is disposed so as to face the upper wall surface and the lower wall surface of the heat treatment furnace 10, respectively. Further, reflectors (reflecting plates) 22 are arranged behind the light sources 20 and on both sides and the rear of the heat treatment furnace 10 so as to surround the heat treatment furnace 10. The inner surface side of each reflector 22 is mirror-polished or the like so that light can be efficiently reflected. The light source 20 for light irradiation may be arranged only above the heat treatment furnace 10.

In the heat treatment furnace 10, the gas introduction passage 2 is provided on the rear side.
4 is formed, and the gas introduction passage 24 is connected to a processing gas supply source such as nitrogen through a gas introduction hole 26 formed in the reflector 22. On the other hand, a gas exhaust passage 28 is formed in the furnace port block 14. Further, O-rings 30 are attached to the furnace port block 14 and the reflector 22 respectively in order to keep the airtightness inside the heat treatment furnace 10 high.

In the light irradiation type heat treatment apparatus having the above-mentioned structure, when the wafer W is inserted into the heat treatment furnace 10 while being supported by the susceptor 18, the opening surface of the furnace port block 14 is closed by the movable flange 16. A treatment gas such as nitrogen is introduced into the heat treatment furnace 10 through the gas introduction passage 24,
The inside of the heat treatment furnace 10 is purged and exhausted through the gas exhaust passage 28. Then, by a wafer temperature detection device and a temperature control (not shown), power is supplied to the upper and lower light irradiation light sources 20 so that the wafer W is heated to a preprogrammed desired temperature, and the wafer W is heated by light irradiation. It When the heat treatment is completed, the wafer W is cooled to a desired temperature in the heat treatment furnace 10 and then unloaded from the heat treatment furnace 10.

By the way, for example, a BPSG film (boron
When performing a reflow process of phosphorus / dope / glass film) or a sintering process of an aluminum wiring film, the components in the film of the wafer W being heated are evaporated, and the evaporated substances adhere to the inner wall surface of the heat treatment furnace 10. That happens. Then, as the number of processed wafers increases, the heat treatment furnace 1
The wall surface of No. 0 is fogged, a part of the light beam from the light source 20 for light irradiation is blocked by the wall surface of the heat treatment furnace 10, and the amount of irradiation light on the wafer W is reduced. Particularly, when the wafer W is heated, the gas in the heat treatment furnace 10 is naturally convected to evaporate the vaporized substances from the wafer W, and
Evaporated substances are remarkably attached to the portion of the inner wall surface of 0 corresponding to directly above the wafer W. As a result, a wafer-shaped fog is formed on the inner wall surface of the heat treatment furnace 10, or unevenness in the clouding occurs depending on the location of the inner wall surface of the heat treatment furnace 10 due to complicated gas flow in the heat treatment furnace 10. in this way,
When the inner wall surface of the heat treatment furnace 10 is fogged, the amount of light actually irradiated onto the wafer W is partially reduced, the temperature uniformity on the surface of the wafer W is impaired, and the heat treatment quality is deteriorated. become.

In order to avoid the above inconveniences, conventionally, the number of processed wafers has been obtained in advance by evaluating the result of the heat treatment of the wafer, and the number of processed wafers has been obtained in advance so that the uniformity of the processing becomes unacceptable. When the number of the heat treatment furnace reaches the predetermined number, the heat treatment furnace 10 is removed from the heat treatment apparatus, the inner wall surface of the heat treatment furnace 10 is cleaned to remove fogging, and then the heat treatment furnace 10 is attached to the apparatus again to restart the heat treatment operation. Was there.

[0008]

However, in the conventional method of removing the heat treatment furnace 10 from the apparatus and cleaning it, the upper reflector 22 is opened, and the heat treatment furnace 10 is pulled up and removed to remove the heat treatment furnace 10. After cleaning the inner wall surface, the heat treatment furnace 10 is mounted again, and the reflector 22 on the upper side is closed. Further, after the heat treatment furnace 10 is attached, it is necessary to perform an operation for confirming the airtightness inside the heat treatment furnace 10. Because of these, there is a problem that the non-operating time of the heat treatment apparatus becomes long and the operating efficiency of the apparatus decreases.

The present invention has been made in view of the above circumstances, and a substance evaporated from a substrate during heat treatment adheres to the inner wall surface of the heat treatment furnace to cause fogging on the inner wall surface itself. It can be effectively prevented, and the recovery work when the number of substrates processed increases is much simpler and requires less time than the method of removing the heat treatment furnace from the equipment and cleaning it. It is an object of the present invention to provide a light irradiation type heat treatment apparatus for a substrate, which can improve the heat treatment.

[0010]

The invention according to claim 1 is
A heat treatment furnace that has an opening for loading and unloading the substrate and accommodates the substrate in a single wafer; a substrate that is supported in a horizontal position to load the substrate into and hold the substrate in the heat treatment furnace. And a substrate supporting means for unloading the substrate from the heat treatment furnace, and a light irradiation and heating means arranged to face at least the upper surface of the substrate supported by the substrate support means in the heat treatment furnace. In the light irradiation type heat treatment apparatus, a light-transmissive member having a size equal to or larger than that of the substrate in a plan view is provided on the substrate support means, and heat treatment is performed on the upper surface of the substrate supported by the substrate support means in the heat treatment furnace. It is characterized in that it is attached so as to intervene with the inner wall surface of the ceiling of the furnace.

According to a second aspect of the present invention, in the heat treatment apparatus according to the first aspect, the light transmissive member supporting means for detachably supporting the light transmissive member is fixed to the substrate supporting means. .

According to a third aspect of the present invention, in the heat treatment apparatus according to the first aspect, a supporting leg portion is fixed to the lower surface side of the light transmitting member, and the light transmitting member is supported on the substrate via the supporting leg portion. It is characterized in that it is detachably supported by the means.

In the light irradiation type heat treatment apparatus of the invention according to claim 1, the substance evaporated from the substrate during the heat treatment of the substrate is between the upper surface of the substrate supported by the substrate supporting means and the inner wall surface of the ceiling portion of the heat treatment furnace. It adheres to the lower surface of the interposed light transmitting member. Since the light transmissive member has a size equal to or larger than that of the substrate in plan view, the substance evaporated from the substrate is blocked by the light transmissive member, so that the inner wall surface of the ceiling portion of the heat treatment furnace is blocked. Does not adhere. In addition, since the light transmissive member transmits the light beam emitted from the light irradiation and heating means similarly to the wall surface of the heat treatment furnace, the light transmissive member is interposed between the substrate and the inner wall surface of the ceiling portion of the heat treatment furnace. There is no inconvenience. When the number of substrates processed increased and the light-transmitting member became cloudy to a level where processing uniformity was unacceptable, the substrate supporting means was taken out of the heat treatment furnace and attached to the substrate supporting means. The light transmissive member is taken out of the heat treatment furnace. After that, when the light transmissive member is detachably attached to the substrate supporting means, it is replaced with a clean light transmissive member, or the light transmissive member is removed from the substrate supporting means and washed again. Attach to substrate support means. Further, when the light transmitting member is integrally attached to the substrate supporting means, the light transmitting member is washed together with the substrate supporting means. In this case, when the substrate supporting means is taken out of the heat treatment furnace, the light transmissive member can be taken out of the heat treatment furnace together with the substrate support means. Therefore, the above operation can be easily performed in a short time. In addition, the light transmissive member is a substrate.
Since it is taken out of the heat treatment furnace every time the sheet is heat-treated, it is possible to replace or wash the light-transmitting member at an appropriate time by checking the degree of fogging of the light-transmitting member each time.

In the heat treatment apparatus according to the second aspect of the present invention, since the light transmissive member is detachably supported by the light transmissive member support means fixed to the substrate support means, the substrate support means is removed from the heat treatment furnace. After extraction, the light transmissive member can be removed from the substrate supporting means, and only the light transmissive member can be replaced with a clean one or only the light transmissive member can be washed.

In the heat treatment apparatus according to the third aspect of the present invention, the light-transmissive member is detachably supported by the substrate supporting means via the supporting leg portion fixed to the lower surface side of the light transmitting member. After pulling out from the heat treatment furnace, remove the light-transmitting member with supporting legs from the substrate supporting means and replace only the light-transmitting member with supporting legs with a clean one, or Only the member can be cleaned.

[0016]

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

FIG. 1 is a schematic side sectional view of a light irradiation type heat treatment apparatus showing an example of an embodiment of the present invention, and FIG. 2 shows a susceptor which is one of the constituent elements of the light irradiation type heat treatment apparatus. It is a top view which shows a principal part. In these FIG. 1 and FIG. 2, the components having the same reference numerals as those used in FIG.
These are the same parts having the same functions as the constituent parts described above with reference to FIG. 3, and a description thereof will be omitted here.

This light irradiation type heat treatment apparatus is provided with a susceptor 18
Three support rods 32 are vertically fixed to the upper surface side of, and a light-transmissive flat plate 34 is detachably supported by these three support rods 32. The light-transmissive flat plate 34 is formed of, for example, quartz glass, which has infrared transmissivity, like the furnace wall of the heat treatment furnace 10. The light-transmissive flat plate 34 has a planar shape that is equal to or larger than that of the semiconductor wafer W, and in the illustrated example, the planar shape is a square. This light-transmissive flat plate 34 is used for the susceptor 18
Attached to the susceptor 18 into the heat treatment furnace 10.
Is inserted into the heat treatment furnace 10 and, as shown in FIG. 1, between the upper surface which is the circuit forming surface of the wafer W supported by the susceptor 18 and the inner wall surface of the ceiling portion of the heat treatment furnace 10. To intervene. Then, by pulling out the susceptor 18 from the inside of the heat treatment furnace 10, the susceptor 18 and the susceptor 18 can be easily taken out of the heat treatment furnace 10.

In the light irradiation type heat treatment apparatus as shown in FIG. 1, the substance evaporated from the upper surface (circuit forming surface) of the wafer W during the heat treatment of the wafer W adheres to the lower surface of the light-transmissive flat plate 34 and is heat treated. It does not adhere to the inner wall surface of the ceiling of the furnace 10. When the number of wafers W to be processed is gradually increased and the light-transmitting flat plate 34 is fogged to a level at which the uniformity of the process becomes unacceptable due to the evaporation material attached to the light-transmitting flat plate 34, the light transmittance is reduced. The flat plate 34 is replaced, or the light-transmissive flat plate 34 in which fogging has occurred is washed. This work is performed by the following procedure.

First, the movable flange 16 is moved to the opposite side of the heat treatment furnace 10 from the state shown in FIG. 1 to open the furnace port block 14. As a result, the light-transmissive flat plate 34 in which fogging has occurred is taken out from the heat treatment furnace 10 together with the susceptor 18. Next, the light-transmissive flat plate 34 is removed from the support rod 32 of the susceptor 18, and a separately prepared clean light-transmissive flat plate 34 is attached to the support rod 32 of the susceptor 18. Alternatively, after the light-transmissive flat plate 34 removed from the susceptor 18 is washed and cleaned, it is attached to the support rod 32 of the susceptor 18 again.

In the above embodiment, the planar shape of the light-transmissive flat plate 34 is square, but the planar shape of the light-transmissive flat plate may be a circle similar to the substrate. Also,
In the above-described embodiment, the support rods 32 are fixed to the susceptor 18, and the light-transmissive flat plate 34 is detachably supported by the support rods 32. However, the susceptor itself does not have the support rods and is the same as the conventional one. On the other hand, the support leg may be fixed to the lower surface side of the light transmissive flat plate, and the light transmissive flat plate may be detachably supported by the susceptor via the support leg. Further, the light-transmissive flat plate may be fixed to the susceptor via a support rod, without making the light-transmissive flat plate detachable from the susceptor. In this case, the susceptor is replaced or washed together with the light-transmissive flat plate. If necessary, a lower light-transmissive flat plate having the same shape and properties as the light-transmissive flat plate 34 may be attached to the heat treatment furnace 1
It may be fixed to the lower surface side of the susceptor 18 via a support rod so as to be interposed between the inner wall surface of the bottom portion of 0 and the lower surface of the wafer W supported by the susceptor 18.

[0022]

When the light irradiation type heat treatment apparatus of the invention according to claim 1 is used, it is possible to prevent the substance evaporated from the substrate during the heat treatment from adhering to the inner wall surface of the heat treatment furnace to cause fogging on the inner wall surface. . Further, since the light transmissive member is taken out of the heat treatment furnace each time one substrate is heat treated,
By checking the degree of fogging of the light transmissive member, it is possible to replace or wash the light transmissive member at an appropriate time, so that the light transmissive member is fogged and the irradiation light amount on the substrate is reduced. There is no fear that the heat treatment quality of the substrate is deteriorated due to partial reduction. In the recovery work when the number of processed substrates is increased, the light-transmissive member is taken out of the heat treatment furnace by extracting the substrate support means from the heat treatment furnace. When it is detachably attached, it can be replaced with a clean light-transmitting member, or the light-transmitting member can be removed from the substrate supporting means, washed, and then attached again to the substrate supporting means. When the member is integrally attached to the substrate supporting means, it can be simply performed by cleaning the light transmitting member together with the substrate supporting means, and the time required for the cleaning can be shortened. It is possible to improve efficiency.

In the heat treatment apparatus according to the second aspect of the present invention, since the light transmissive member is detachably supported by the light transmissive member support means fixed to the substrate support means, the substrate support means is removed from the heat treatment furnace. After extraction, it is possible to replace only the light transmissive member with a clean one or to wash only the light transmissive member, and the operation can be easily performed.

In the heat treatment apparatus according to the third aspect of the present invention, since the light transmissive member is placed on the substrate supporting means via the supporting legs, after the substrate supporting means is taken out of the heat treatment furnace, It is possible to replace only the light transmissive member having the supporting legs with a clean one or to wash only the light transmissive member, and the operation can be easily performed.

[Brief description of drawings]

FIG. 1 is a schematic side sectional view of 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 main part of a susceptor which is one of the constituent elements of the light irradiation type heat treatment apparatus shown in FIG.

FIG. 3 is a schematic side sectional view showing an example of a conventional light irradiation type heat treatment apparatus.

[Explanation of symbols]

 10 Heat Treatment Furnace 12 Heat Treatment Furnace Opening 14 Furnace Mouth Block 16 Movable Flange 18 Susceptor 20 Light Source for Light Irradiation 22 Reflector (Reflector) 24 Gas Introducing Path 28 Gas Exhausting Path 32 Susceptor Support Rod 34 Light-Transparent Flat Plate

Claims (3)

[Claims] 1. A heat treatment furnace having an opening for loading and unloading a substrate, and a substrate for accommodating the substrate in a single-wafer manner, and carrying the substrate into and out of the heat treatment furnace while supporting the substrate in a horizontal posture. Substrate supporting means for holding the substrate in the furnace and unloading the substrate from the heat treatment furnace, and light irradiation heating disposed so as to face at least the upper surface of the substrate supported by the substrate support means in the heat treatment furnace. In the light irradiation type heat treatment apparatus for a substrate, the substrate supporting means includes a light-transmissive member having a size equal to or larger than the substrate in a plan view to the substrate supporting means in the heat treatment furnace. A light irradiation type heat treatment apparatus for a substrate, characterized in that it is attached so as to be interposed between the upper surface of the supported substrate and the inner wall surface of the ceiling of the heat treatment furnace. 2. The light irradiation type heat treatment apparatus for a substrate according to claim 1, wherein a light transmitting member supporting means for detachably supporting the light transmitting member is fixed to the substrate supporting means. 3. The substrate light according to claim 1, wherein the support leg is fixed to the lower surface side of the light transmissive member, and the light transmissive member is detachably supported by the substrate supporting means via the support leg. Irradiation type heat treatment equipment.