JPH07245274A - Heat treatment device - Google Patents

Abstract

PURPOSE:To provide a heat treatment device which can uniformly heat and treat a body to be treated at a constant temperature by allowing a light transmission material to absorb not only infrared rays with an unneeded wavelength from a light source but also infrared rays radiated from the body to be treated for preventing heating. CONSTITUTION:A light transmission window 5 consisting of a light transmission material 4 facing a body W to be treated is provided at a treatment chamber 2 for housing the body W to be treated and then performing its heat treatment. A light source 7 is provided for heating the body W to be treated by applying light via the light transmission material 4 of the light transmission window 5. The light transmission material 4 of the light transmission window 5 is provided at a plurality of layers 4a and 4b and a cooling, layer 26 is provided for cooling the light transmission materials 4a and 4b through a refrigerant F of a cooling gas, etc., between the light transmission material 4a and 4b, thus preventing the light transmission materials 4a and 4b from absorbing infrared rays, etc., radiated from the body W to be treated for heating.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat treatment apparatus, and more particularly to a heat treatment apparatus for heating an object to be processed by light irradiation from a light source.

[0002]

2. Description of the Related Art In manufacturing a semiconductor wafer, which is an object to be processed, oxidation, diffusion, CVD (Chemical Vapor D
Various heat treatment apparatuses are used to perform processing such as eposition). Then, as one of the heat treatment apparatuses, a light irradiation type heat treatment apparatus using a light source as a heating means has been proposed (for example, Japanese Patent Publication No. 34164/1990).

In this type of heat treatment apparatus, a processing chamber for accommodating and heat-treating a wafer is formed of a light-transmitting material such as quartz, and a light source provided outside the processing chamber transmits light (infrared rays) to the wafer through a wall surface of the processing chamber. ) Is applied to heat the wafer. In this case, in order to improve the quality and productivity of the wafer, it is important to uniformly heat the wafer at a constant temperature.

[0004]

However, in the conventional heat treatment apparatus, the light transmitting material not only absorbs infrared rays of an unnecessary wavelength from the light source to heat them (temperature rise) but also infrared rays emitted from the wafer. However, there is a problem in that it is difficult to uniformly heat the wafer at a constant temperature due to the disturbance of infrared rays radiated from the light transmitting material. In addition, in Japanese Patent Publication No. 2-34164,
A heat treatment apparatus is described in which an intermediate member that absorbs infrared rays radiated from the light transmissive material is disposed between the light transmissive material and the wafer. It is difficult to uniformly heat the wafer at a constant temperature because it absorbs infrared rays radiated from the wafer and heats it.

Therefore, an object of the present invention is to prevent the light transmitting material from absorbing and heating not only infrared rays of unnecessary wavelengths from the light source but also infrared rays radiated from the object to be processed, thereby keeping the object to be processed constant. An object of the present invention is to provide a heat treatment apparatus capable of uniformly performing heat treatment at the above temperature.

[0006]

In order to achieve the above object, a heat treatment apparatus according to a first aspect of the present invention is provided with a processing chamber for accommodating and heat treating an object to be processed, and the processing chamber facing the object to be processed. A light transmitting window made of the light transmitting material, and a light source for heating the object to be processed by light irradiation through the light transmitting material of the light transmitting window, and the light transmitting material of the light transmitting window is provided in a multi-layer, A cooling layer for cooling the light transmitting material is formed between these light transmitting materials by passing a coolant such as a cooling gas.

It is preferable that the light transmitting material is a multi-layer, for example, a double layer in terms of downsizing of the heat treatment apparatus, but it may be a triple layer or more. As the refrigerant, a cooling gas such as an inert gas is preferable from the viewpoint of the structure of the heat treatment apparatus, but cooling water or the like may be used. A filament lamp such as a halogen lamp, an arc lamp, or the like can be applied as the light source, and a semiconductor wafer or an LCD substrate or the like can be applied as the object to be processed.

A heat treatment apparatus according to a second aspect is the heat treatment apparatus according to the first aspect, wherein the cooling layer is provided with a light amount adjusting plate for adjusting a light amount. As the light amount adjusting plate, for example, a ring-shaped quartz plate or a quartz plate in which a large number of small holes are formed vertically or obliquely can be applied.

Further, in the heat treatment apparatus according to the third aspect of the present invention, there is provided a processing chamber for accommodating the object to be processed and performing heat treatment, and a light transmitting window made of a light transmitting material provided in the processing chamber so as to face the object. A light source that heats the object to be processed by light irradiation through the light-transmitting material of the light-transmitting window, and by providing a gas introduction port for processing gas or the like in the light-transmitting material of the light-transmitting window, The present invention is characterized in that a rectifying plate is provided to allow the processing gas to flow along the inner surface of the light transmitting material in order to cool the light transmitting material.

[0010]

According to the heat treatment apparatus of the first aspect, the light transmitting material of the light transmitting window is provided in a plurality of layers, and a cooling layer for cooling the light transmitting material is formed between the light transmitting materials by passing a coolant such as a cooling gas. Therefore, even if the light transmitting material absorbs an infrared ray of an unnecessary wavelength from the light source or an infrared ray radiated from the object to be processed, it is not heated. Therefore, since unnecessary infrared rays are not radiated from the light transmitting material, the object to be processed can be heated uniformly at a constant temperature, and the quality and productivity of the object to be processed can be improved.

According to the heat treatment apparatus of the second aspect, since the cooling layer is provided with the light amount adjusting plate for adjusting the light amount, it becomes possible to give the light amount necessary for the heat treatment to the object to be processed. The quality of the body can be further improved.

According to the heat treatment apparatus of the third aspect, the light transmitting material of the light transmitting window is provided with a gas inlet for processing gas or the like, and the processing gas is introduced so as to cool the light transmitting material. Since the rectifying plate that flows along the inner surface of the transmissive material is provided, even if the light transmissive material absorbs infrared rays of an unnecessary wavelength from the light source or infrared rays radiated from the object to be processed, it does not heat. Therefore, like the heat treatment apparatus according to claim 1, since unnecessary infrared rays are not radiated from the light transmitting material, it becomes possible to uniformly heat the object to be processed at a constant temperature, and the quality of the object to be processed can be improved. And productivity can be improved.

[0013]

Embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

FIG. 1 is a sectional view showing a heat treatment apparatus which is a first embodiment of the present invention. This heat treatment apparatus 1 is provided with a processing chamber 2 for accommodating, for example, a semiconductor wafer W, which is an object to be processed, and performing various heat treatments such as oxidation, diffusion, annealing, and CVD on the semiconductor wafer W. The processing chamber 2 has a heat-resistant vertical cylindrical body 3 made of, for example, stainless steel, and a light-transmitting material 4 provided at the upper open end 3a of the body 3 so as to face the wafer W. A transparent window 5 and a lid 6 arranged below the light transparent window 5 so as to face the light transparent window 5 are partitioned from each other. Above the body 3, the light transparent material 4 of the light transparent window 5 is formed.
A plurality of halogen lamps 7 which are filament lamps are provided as a light source for heating the wafer W in the processing chamber 2 by light irradiation.

A flange portion 8 is provided on an upper inner peripheral portion of the body portion 3.
Is formed, and the lid body 6 is horizontally abutted on the lower opening end 8a of the flange portion 8 so as to openably close the flange portion 8. The lid 6 is made of, for example, stainless steel similar to the body 3, and an O-ring 9 made of, for example, fluororubber for sealing with the flange 8 is attached to the peripheral portion of the lid 6. On the upper surface of the lid body 6, a plurality of, for example, three support pins 10 made of, for example, quartz for vertically supporting the lower surface of the wafer W are provided upright at equal intervals in the circumferential direction.

Further, cooling water passages 11 and 12 for cooling the O-ring 9 and the like are formed in the lid 6 and the body portion 3, and the body portion 3 is provided with nitrogen for gas replacement in the processing chamber 2. An inlet port 13 for introducing an inert gas such as a gas or a processing gas G such as an oxygen gas for wafer processing and an exhaust port 14 for exhausting these gases out of the processing chamber 2 are provided. A supply system for the processing gas G or the like is connected to the introduction port 13, and a factory exhaust system is connected to the exhaust port 14 via, for example, a vacuum pump or an abatement device (not shown).

A base 15 made of, for example, stainless steel is provided in the lower portion of the body 3 so as to form the bottom thereof, and the base 6 is penetrated through the lower portion of the base 15 to cover the lid 6.
An elevating mechanism 16 including, for example, an air cylinder for moving up and down to open and close is provided. A portion below the flange portion 8 of the body portion 3 is formed as a wafer transfer space portion 17, and the lid body 6 is lowered in the wafer transfer space portion 17 by an elevating mechanism 16 as shown by an imaginary line in FIG. It is supposed to be moved.

The wafer transfer space 1 is provided in the body 3.
Carry-in port 1 for communicating with 7 and carrying in / out the wafer W
8 and a carry-out port 19 are provided, the unprocessed wafer W is transferred from the carry-in port 18 onto the support pins 10 of the lid 6 by a transfer device (not shown), and the processed wafer W is illustrated from the carry-out port 19. No transfer device is used. Gate valves 20 and 21 for opening and closing are provided at the carry-in port 18 and the carry-out port 19, respectively.

On the other hand, the light-transmitting material 4 of the light-transmitting window 5 is formed of a heat-resistant and light-transmitting material, for example, transparent quartz, into a circular flat plate shape, and has multiple layers, for example, outer and inner double layers. It is provided on 4a and 4b. The light transmitting member 4b on the inner side is attached to the upper opening end 8b of the flange portion 8 of the body portion 3 by an O-ring 22 and a mounting member 23 which are sealing means.
The outer light transmitting material 4a is airtightly attached to the upper open end 3a of the body 3 via the O-ring 24 and the attachment member 25.

The light transmitting materials 4a and 4b are, for example, 5 to 5
A cooling layer 26 for cooling the light transmissive materials 4a and 4b is disposed between the light transmissive materials 4a and 4b in parallel with a gap s of about 10 mm. An introduction port 27 for introducing a cooling gas F, which is an inert gas such as nitrogen gas, as a refrigerant into the cooling layer 26 in the body portion 3 and an exhaust port for discharging the cooling gas F to the outside of the cooling layer 26. 28 is formed.

The inlets 27 and the outlets 28 for the cooling gas F have slit-shaped openings along the circumferential direction of the body 3 in order to allow the cooling gas F to flow uniformly into the cooling layer 26. It is preferable that they are formed continuously and facing each other. In addition, the light transmitting materials 4a and 4b
In order to maintain the temperature of the cooling gas constant, for example, the temperature of the cooling gas discharged from the exhaust port 28 is detected, and the detection port temperature is set to a constant temperature (set temperature).
It is preferable to control the supply amount of the cooling gas from the control valve via the control valve.

A concave reflecting mirror 29 is attached to the upper opening end 3a of the body 3 so as to cover it, and the halogen lamp 7 as the light source is arranged inside the reflecting mirror 29. It is preferable that the halogen lamp 7 emits infrared rays having a wavelength of about 0.9 to 1.2 μm in order to minimize absorption into the light transmitting material made of quartz. As the reflecting mirror 29, for example, a concave body made of stainless steel and having an inner surface plated with gold is preferable. The outside of the reflecting mirror 29 is covered with an outer plate 31 made of, for example, stainless steel via a heat insulating space 30, and a water cooling pipe 32 for cooling is arranged in the heat insulating space 30.

Next, the operation of the first embodiment will be described. When the wafer W is subjected to a process such as oxidation, the halogen lamp 7 of the light source is turned on and the cooling layer 26 of the light transmission window 5 is provided.
Then, the cooling gas F is supplied and discharged to keep the light transmitting materials 4a and 4b at a predetermined temperature, for example, 400 ° C. or lower, preferably about 200 to 300 ° C.

In this state, the lid 6 is moved downward as shown by the phantom line in FIG. 1 to open the lower part of the processing chamber 2,
After the processing chamber 2 and the wafer transfer space 17 are replaced with an inert gas, the unprocessed wafer W is transferred onto the support pins 10 of the lid 6 from the carry-in port 18. Then, the lid 6 is moved upward by the elevating mechanism 16 to move the wafer W to the processing chamber 2
While closing the lower part of the processing chamber 2 with the lid 6 while
The processing gas G is supplied to and discharged from the processing chamber 2 in a predetermined processing gas atmosphere, and the heat treatment of the wafer W is performed at a predetermined processing temperature, for example, about 800 to 1200 ° C.

After the heat treatment is completed, the inside of the processing chamber 2 is replaced with an inert gas, and then the lid 6 is moved downward to open the lower portion of the processing chamber 2 and after the treatment is performed from above the support pins 10 of the lid 6. The wafer W is unloaded through the unloading port 19. And
The next wafer W is transferred onto the support pins 10 of the lid body 6,
Thereafter, the heat treatment of the wafers W is sequentially performed one by one in the same cycle.

According to the heat treatment apparatus 1 configured as described above, the light transmitting material 4 of the light transmitting window 5 is provided in the double layers 4a and 4b, and the cooling gas F as a refrigerant is provided between the light transmitting materials 4a and 4b. Cooling layer 26 for cooling the light transmitting materials 4a and 4b through
Therefore, even if the light transmitting materials 4a and 4b absorb infrared rays having an unnecessary wavelength from the halogen lamp 7 which is a light source or infrared rays radiated from the wafer W, they are not heated. Therefore, since unnecessary infrared rays are not radiated from the light transmitting materials 4a and 4b, the wafer W can be uniformly heated at a constant temperature, and the wafer W is always subjected to a constant heat treatment with good reproducibility. Wafer W
Quality and productivity (throughput) can be improved. Further, since the light transmitting materials 4a and 4b of the light transmitting window 5 do not heat even if they absorb the infrared rays radiated from the wafer W,
It is possible to reduce the volume of the processing chamber 2 by narrowing the gap between the light transmitting materials 4a and 4b and the wafer W, and it is possible to reduce the size of the heat treatment apparatus 1 and reduce the manufacturing cost.

In the heat treatment apparatus 1, any one of the two light transmitting materials 4a and 4b of the light transmitting window 5 can be depressurized so that the inside of the processing chamber 2 can be depressurized by vacuum substitution or reduced pressure CVD. One or both of them may be formed thick for pressure resistance. Further, the light transmitting materials 4a and 4b of the light transmitting window 5
Is doubled, but may be tripled or more.
Further, as the refrigerant supplied to the cooling layer 26, for example, air may be used instead of the inert gas, or pure water or the like can be applied.

FIG. 2 is a sectional view showing a heat treatment apparatus which is a second embodiment of the present invention. In this embodiment, the same parts as those in the first embodiment are designated by the same reference numerals, and the description of those parts will be omitted. The heat treatment apparatus 1 of the present embodiment includes a light amount adjusting plate 33 for adjusting the light amount in the cooling layer 26. That is, a step portion 34 is formed on the inner peripheral portion of the body portion 3 that divides the cooling layer 26, and the light amount adjusting plate 33 is mounted on the step portion 34.

As shown in FIG. 3, the light quantity adjusting plate 33 is formed of, for example, quartz in a ring shape, and the quantity or light of the light emitted from the halogen lamp 7 of the light source to the wafer W depends on the diameter of the opening 33a. The energy can be adjusted. Further, the body portion 3 has an introduction port 27 for supplying / discharging the cooling gas F between the light quantity adjusting plate 33 and the outer light transmitting material 4a and between the light quantity adjusting plate 33 and the inner light transmitting material 4b. The exhaust port 28 is formed by branching. According to the heat treatment apparatus 1 of the present embodiment, the same effects as those of the first embodiment can be obtained, and in addition, the light quantity adjustment plate 33 allows the light quantity or light energy required for heat treatment to be applied to the wafer W.
Therefore, the quality of the wafer W can be further improved.

As the light quantity adjusting plate 33, as shown in FIG. 4, a large number of small holes 35 are vertically formed in a quartz disc, or as shown in FIG. 5, a large number is formed in a quartz disc. The small hole 36 may be formed obliquely. In these light amount adjusting plates 33, the infrared rays of a specific wavelength are transmitted and absorbed by the quartz plate, and in the case of the vertical small holes 35, the infrared rays pass through these small holes 35 as they are. In the case of 36, infrared rays are attenuated by reflection, refraction, etc. in these small holes 36.

The quartz forming the light quantity adjusting plate 33 may be transparent or semi-transparent. Further, as the light quantity adjusting plate 33, sapphire, a polarizing plate or the like can be applied other than quartz.

FIG. 6 is a sectional view showing a heat treatment apparatus which is a third embodiment of the present invention. In the present embodiment, the same parts as those in the first and second embodiments are designated by the same reference numerals, and the description of those parts will be omitted. In the heat treatment apparatus 1 of the present embodiment, the quartz light-transmitting material 4 of the light-transmitting window 5 is not doubled, and the upper opening end 3a of the body 3 is slightly separated from the wafer W in the processing chamber 2. It is installed airtightly.

The light transmitting material 4 is formed on the upper open end 3a of the body portion 3.
Has a peripheral edge portion 4e that is in contact with the peripheral edge portion 4e, and is formed to bulge in a substantially conical or funnel shape with a gentle inclination from the peripheral edge portion 4e toward the central portion. A gas inlet 37 for introducing a processing gas or an inert gas into the processing chamber 2 is provided in the center of the light transmitting material 4.
A gas introducing pipe portion 38 opened as a vertical rises and is integrally formed. The gas introducing pipe portion 38 penetrates through the reflecting mirror 29 and the outer plate 31 and is guided to the outside, and is supplied to a supply system (not shown) for processing gas or the like. It is connected.

A straightening plate 3 for flowing the processing gas G along the inner surface of the light transmitting material 4 in order to cool the light transmitting material 4 by the processing gas G introduced into the inner central portion of the light transmitting material 4.
9 is provided. The rectifying plate 39 is made of, for example, quartz in a disk shape larger than the diameter of the gas introducing port 37, and is horizontally provided via a supporting rod 40 made of, for example, quartz so as to cover the gas introducing port 37 with a gap therebetween. It is fixed to.

According to the heat treatment apparatus 1 of the present embodiment, the gas introducing port 37 is provided in the light transmitting material 4 of the light transmitting window 5 and the processing gas G is introduced so as to cool the light transmitting material 4. Since the rectifying plate 39 that allows G to flow along the inner surface of the light transmitting material 4 is provided, the light transmitting material 4 causes the infrared rays of the unnecessary wavelength from the halogen lamp 7 of the light source or the wafer W to be emitted.
It does not heat even if it absorbs infrared rays radiated from it. Therefore, since unnecessary infrared rays are not radiated from the light transmitting material 4, the wafer W can be heated uniformly at a constant temperature, and the quality and productivity of the wafer can be improved.

The present invention is not limited to the above embodiment, but various modifications can be made within the scope of the gist of the present invention. For example, the body portion 3 of the above-described embodiment is formed in a cylindrical shape corresponding to the shape (circular shape) of the wafer W to be processed, but it may be a square shape, a polygonal shape, or the like. Also,
The body 3 of the above embodiment is provided with a shutter for thermally shielding the space between the processing chamber 2 and the wafer transfer space 17 when the lid 6 is moved down into the wafer transfer space 17. You may do it.

In the above-mentioned embodiment, the wafer W is left stationary on the lid 6 via the support pins 10. However, the wafer W can be rotated in the processing chamber 2 via the support made of, for example, quartz. It may be movably supported. As the object to be processed, for example, an LCD substrate or the like can be applied in addition to the semiconductor wafer, and as the light source, an arc lamp or the like can be applied in addition to the filament lamp.

[0038]

In summary, according to the present invention, the following excellent effects can be obtained.

(1) According to the heat treatment apparatus of the first aspect, the light-transmitting material of the light-transmitting window is provided in multiple layers, and a cooling medium such as a cooling gas is passed between the light-transmitting materials to cool the light-transmitting material. Since the layer is formed, it does not heat even if the light transmitting material absorbs an infrared ray having an unnecessary wavelength from the light source or an infrared ray radiated from the object to be processed. Therefore, since unnecessary infrared rays are not radiated from the light transmitting material, the object to be processed can be heated uniformly at a constant temperature, and the quality and productivity of the object to be processed can be improved.

(2) According to the heat treatment apparatus of the second aspect, since the cooling layer is provided with the light quantity adjusting plate for adjusting the light quantity, it becomes possible to give the light quantity necessary for the heat treatment to the object to be processed. Further, the quality of the object to be processed can be further improved.

(3) According to the heat treatment apparatus of the third aspect, the light-transmitting material of the light-transmitting window is provided with a gas inlet for processing gas or the like, and the light-transmitting material is cooled by the processing gas introduced. Since a rectifying plate that allows the gas to flow along the inner surface of the light-transmitting material is provided, even if the light-transmitting material absorbs infrared rays of unnecessary wavelength from the light source or infrared rays radiated from the object to be processed, it can be heated. There is no. Therefore, like the heat treatment apparatus according to claim 1, since unnecessary infrared rays are not radiated from the light transmitting material, it becomes possible to uniformly heat the object to be processed at a constant temperature, and the quality of the object to be processed can be improved. And productivity can be improved.

[Brief description of drawings]

FIG. 1 is a sectional view showing a heat treatment apparatus which is a first embodiment of the present invention.

FIG. 2 is a sectional view showing a heat treatment apparatus which is a second embodiment of the present invention.

FIG. 3 is a perspective view of a light amount adjusting plate used in the heat treatment apparatus of FIG.

FIG. 4 is a cross-sectional view showing another example of the light amount adjusting plate.

FIG. 5 is a cross-sectional view showing another example of the light amount adjusting plate.

FIG. 6 is a sectional view showing a heat treatment apparatus which is a third embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Heat treatment apparatus 2 Processing chamber 4, 4a, 4b Light transmission material 5 Light transmission window 7 Halogen lamp (light source) 26 Cooling layer 33 Light intensity adjusting plate 37 Gas inlet 39 Rectifier plate W Semiconductor wafer (processing target) F Cooling gas ( Refrigerant) G processing gas

Claims (3)

[Claims] 1. A processing chamber for accommodating an object to be processed and performing heat treatment, a light transmitting window made of a light transmitting material provided in the processing chamber so as to face the object, and a light transmitting material of the light transmitting window. And a light source that heats the object to be processed by light irradiation, the light transmission material of the light transmission window is provided in multiple layers, and a cooling layer that cools the light transmission material by passing a coolant such as a cooling gas between the light transmission materials. A heat treatment apparatus characterized in that 2. The heat treatment apparatus according to claim 1, wherein the cooling layer is provided with a light amount adjusting plate for adjusting the light amount. 3. A processing chamber for accommodating an object to be processed and performing a heat treatment, a light transmitting window made of a light transmitting material provided in the processing chamber so as to face the object, and a light transmitting material of the light transmitting window. And a gas source for heating the object to be processed by light irradiation through the light-transmitting window and providing a gas inlet for the processing gas or the like in the light-transmitting material of the light-transmitting window, and the processing gas for cooling the light-transmitting material by the introduced processing gas. A heat treatment apparatus, characterized in that a rectifying plate is provided to allow the air to flow along the inner surface of the light transmitting material.