JPH09148262A - Heat processing method and its device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To form a process film uniformly in a face on a surface of a substrate to be processed by a method wherein process gas is supplied to the surface of the substrate to be processed by diving it into a plurality of concentric areas and changing a flow volume. SOLUTION: A gas supply part is partitioned into three concentric chambers, namely first, second and third gas supply chambers R1, R2 and R3 so that is can be supplied with process gas to a surface of an arc-shaped wafer W by diving it into a plurality of concentric areas, for example three areas E1, E2 and E3 of a center part, an intermediate part and a marginal part and by changing a flow volume. These gas supply chambers R1, R2 and R3 are structured so that the process gas is divided into the plurality of concentric areas at a specific area ratio increasing in a radial direction from a center with respect to the surface of the wafer W, for example at an area ratio of 0.5 to 1.5 vs. 2.0 to 4.0 vs 4.0 to 6.0, preferably at an area ratio of 1:3:5, and the process gas can be supplied at the same flow volume ratio as the area ratio.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a heat treatment method and an apparatus therefor.

[0002]

2. Description of the Related Art In a semiconductor device manufacturing process, oxidation, diffusion, CV
Various heat treatment apparatuses are used to perform processing such as D (Chemical Vapor Deposition). The typical heat treatment apparatus carries a large number of wafers, for example, about 150 wafers, which are vertically supported at predetermined intervals from below through a wafer boat into a vertical reaction tube forming a processing chamber and loads these wafers. Heat treatment is performed at a high temperature in a processing gas atmosphere.

In this batch processing type heat treatment apparatus, a large number of wafers can be heat treated at one time, which is sufficient for a certain degree of heat treatment, but the upper wafer and the lower wafer supported by the wafer boat are used. Since there is a distance between and, there is a time lag between the thermal environment when loading and unloading in the processing furnace, and it takes some time to load and unload, so all heat treatments that require rapid temperature rise and fall are carried out. There is a limit to the uniform application to the wafer.

Therefore, the development of a single-wafer processing type heat treatment apparatus capable of performing a heat treatment requiring a rapid temperature increase / decrease suitable for increasing the diameter of the wafer and miniaturizing the semiconductor element by processing the wafers one by one is advanced. Has been. This single wafer processing type heat treatment apparatus has a vertical reaction tube 1 forming a processing chamber as shown in FIG. 12, for example, and the processing gas flows through the reaction tube 1 from top to bottom. Thus, the processing gas supply pipe 40 and the exhaust pipe 3 are provided.

A heating part 4 having a soaking body 5 is provided above the reaction tube 1, and the periphery of the heating part 4 and the reaction tube 1 is covered with a heat insulating material 6. A wafer holder 14 that can move up and down at a high speed, for example, 150 to 200 mm / sec is provided in the reaction tube 1, and the wafer W is placed on the wafer holder 14 in a transfer area (not shown) below the reaction tube. Then, this is moved up to a predetermined heat treatment region to perform heat treatment.

[0006]

However, in the above heat treatment apparatus, when the processing gas is vertically supplied to the surface of the wafer W to form the processing film F such as an oxide film as shown in FIG. There is a problem that the film thickness of the film F becomes thick at the peripheral portion of the wafer, and the film is non-uniformly formed in the plane. It is considered that this is because when the processing gas is supplied perpendicularly to the surface of the wafer, the gas flow of the processing gas poured near the central portion of the wafer bounces near the peripheral portion of the wafer. Therefore, an object of the present invention is to solve the above problems and provide a heat treatment method and apparatus capable of forming a treatment film uniformly on the surface of a substrate to be treated and achieving a highly uniform heat treatment. Especially.

[0007]

In order to achieve the above-mentioned object, the invention according to claim 1 of the present invention is to perform heat treatment while supplying a processing gas vertically to the surface of a substrate to be processed housed in a processing chamber. The heat treatment method is characterized in that the processing gas is divided into a plurality of concentric regions with respect to the surface of the substrate to be processed and supplied at different flow rates.

The processing gas is divided into a plurality of concentric regions with respect to the surface of the substrate to be processed and supplied at different flow rates, so that the gas flow of the processing gas poured near the central portion of the substrate to be processed is covered. It is possible to suppress the bounce around the peripheral portion of the processing substrate, and it is possible to form the processing film uniformly on the surface of the processing substrate.

According to a second aspect of the present invention, there is provided a heat treatment method of performing heat treatment while supplying a processing gas perpendicularly to the surface of the substrate to be processed housed in the processing chamber, wherein the processing gas is applied to the surface of the substrate to be processed. It is characterized in that it is divided into a plurality of concentric circular regions at a predetermined area ratio increasing in the radial direction from the center and is supplied at the same flow rate ratio as the area ratio.

For example, when the surface of the substrate to be processed is concentrically divided into three regions of a central part, an intermediate part and a peripheral part at an area ratio of 1: 3: 5, the processing gas is supplied at the same flow ratio as this area ratio. To supply. The processing gas is divided into a plurality of concentric circular regions with a predetermined area ratio increasing from the center to the surface of the substrate to be processed in the radial direction, and is supplied at the same flow rate ratio as the area ratio, thus It is possible to sufficiently prevent the gas flow of the processing gas that is poured near the substrate from bouncing back near the peripheral edge of the substrate to be processed, and it is possible to form a processing film uniformly on the surface of the substrate to be processed. It will be possible.

According to the third aspect of the present invention, the processing gas is supplied from the upper part of the processing chamber to the lower part, and the substrate to be processed is moved upward from the lower part to a predetermined heat treatment area so that the processing gas hits the surface vertically. In the heat treatment method, the processing gas is divided into a plurality of concentric regions with respect to the surface of the substrate to be processed, and the central side flow rate is higher than the peripheral side flow rate when the processing substrate is in the low position, The feature is that the amount is reduced at times.

The processing gas is divided into a plurality of concentric regions with respect to the surface of the substrate to be processed, and the flow rate on the center side is larger than that on the peripheral side when the substrate is in the low position and is small in the high position. As a result, during the process of moving the substrate to be processed from the low position to the high position which is the heat treatment area, the gas flow of the processing gas that is poured near the central portion of the substrate is repelled near the peripheral portion of the substrate. It becomes possible to suppress, and it becomes possible to form a treatment film uniformly on the surface of the substrate to be treated. In this case, when the substrate to be processed is at the intermediate position, it is preferable that the center side flow rate be the same as the peripheral side flow rate.

According to a fourth aspect of the present invention, in a heat treatment apparatus for performing a heat treatment while supplying a processing gas perpendicularly to the surface of a substrate to be processed housed in the processing chamber, the processing gas is supplied to the surface of the substrate to be processed in the processing chamber. On the other hand, it is characterized in that a gas supply unit is provided, which is divided into a plurality of concentric areas and supplies a different flow rate.

Since the processing gas is provided in the processing chamber so as to divide the processing gas into a plurality of concentric regions with respect to the surface of the substrate to be processed and to change the flow rate, the processing gas is supplied near the center of the substrate to be processed. It is possible to suppress the gas flow of the processing gas being poured from bouncing around the peripheral portion of the substrate to be processed, and it is possible to uniformly form a processing film on the surface of the substrate to be processed.

[0015]

Embodiments of the present invention will be described below in detail with reference to the accompanying drawings. In FIG. 1, which shows a vertical cross-sectional structure of a heat treatment apparatus, reference numeral 1 is a reaction tube (process tube) forming a processing furnace or a processing chamber configured to perform, for example, an oxidation process on a substrate to be processed, for example, a semiconductor wafer W. The reaction tube 1 is formed of a heat-resistant material such as quartz in a vertical cylindrical shape with an upper part closed and an lower part open.

The upper part of the reaction tube 1 is treated as described later.
Gas or nitrogen for purging inside the furnace (N 2) Inert such as gas
A gas supply unit 2 for supplying gas is provided below the reaction tube 2.
Exhaust exhaust gas or inert gas after processing on the side wall
An exhaust pipe 3 is provided so that the processing gas flows in the reaction pipe 1 from above.
It is configured to flow downward. In the exhaust pipe 3
An exhaust system is connected through a detoxifying device, etc.
An exhaust device was provided to make the inside of the reaction tube 1 a predetermined depressurized atmosphere.
It may be.

Above the reaction tube 1, as a heating means for heating the wafer W to a high temperature, for example, about 800 to 1200 ° C., a planar heating portion 4 is horizontally arranged so as to face the wafer W. The heating unit 4 spirally or meanders a resistance heating element such as a Kanthal wire made of an alloy of iron (Fe), chromium (Cr) and aluminum (Al) or a heating wire made of molybdenum disilicide (MoSi ₂ ). It is formed in a flat shape by arranging in a shape.

The heating unit 4 is formed to be sufficiently larger (for example, twice or more) than the size (diameter) of the wafer W so that the radiant heat can be uniformly applied to the wafer W in the vertical direction. preferable. In order to eliminate the temperature difference within the surface of the wafer W caused by the finite size of the heating unit 4, the peripheral portion of the heating unit 4 may be formed in a stepped shape or curved downward.

Between the heating part 4 and the reaction tube 1, for example, alumina (Al
A soaking body 5 made of ₂ O ₃ ) or silicon carbide (SiC) having a heavy metal contamination preventing property and a soaking property is arranged. The heat equalizer 5 and the outside of the heating unit 4 are covered with a heat-resistant heat insulating material 6 such as quartz wool, and the outside of the heat insulating material 6 is covered with a double structure casing 7 made of, for example, stainless steel. ing. The casing 7 preferably has a water cooling jacket structure in order to prevent thermal influence on the outside.

A lower casing 9 made of a heat-resistant material, such as quartz or stainless steel, for partitioning and forming a vertical transfer space 8 is connected to the lower portion of the reaction tube 1 through an airtight member (not shown) such as an O-ring. A vertical elevating shaft 10 made of, for example, quartz is pierced through an airtight member 11 so that the lower casing 9 can move up and down. The lower end of the elevating shaft 10 is supported by an elevating arm 13 of an elevating mechanism 12 composed of, for example, a ball screw,
The lift arm 13 is provided with a rotation drive unit M such as an electric motor for rotating the lift shaft 10.

A wafer holder 14 made of, for example, quartz, which is a support for horizontally supporting a single wafer W, that is, one wafer W, is provided at the upper end of the elevating shaft 10. The wafer holder 14 has a plurality of support arms 14a that open upward, for example, three support arms 14a that support the peripheral portion of the wafer at three points.

The lower casing 9 is provided with one or a plurality of stages, for example, upper and lower two stages of shutters S1 and S2 in order to thermally isolate the internal transport space 8 from the reaction tube 1.
The upper and lower shutters S1 and S2 are used to convey the space 8
Is divided into an upper intermediate chamber 15 and a lower wafer transfer chamber 16 each having a size capable of accommodating the wafer holder 14. The upper and lower shutters S1 and S2 are horizontally driven in a direction toward or away from each other, for example, a pair of left and right shutter plates 17a and 17b that are linearly driven, and an air cylinder that opens and closes each pair of shutter plates 17a and 17b. The shutter drive unit 18 is mainly configured.

The shutter plates 17a and 17b are preferably made of a heat-resistant material such as opaque quartz or stainless steel, and preferably have a heat insulating space or a heat resistant heat insulating material inside. Each pair of shutter plates 17a,
17b is configured to overlap vertically when closed, and a semicircular cutout portion (not shown) is formed at the tip end thereof to allow the rotation and the vertical movement of the lifting shaft 10 in the closed state. Further, the shutter plates 17a and 17b have a first closed position that allows the rotation and the vertical movement of the lifting shaft 10,
It is preferably configured to be closed in two stages, a fully closed second closed position.

The intermediate chamber 15 and the wafer transfer chamber 16 defined by the upper and lower shutters S1 and S2 have a structure in which an inert gas is supplied and discharged in order to prevent the processing gas and heat from being accumulated. Is preferred. The wafer transfer chamber 16 has a loading side and a unloading side for replacing the atmosphere with an inert gas when the wafer W is loaded into the wafer loading chamber 16 from the outside and when the wafer W is loaded from the wafer loading chamber 16 to the outside. Side load lock chambers 19 and 20 are connected in series via inner gate valves G1 and G2, and outside gate valves G that communicate with the outside through these load lock chambers 19 and 20.
1, G2 are provided. Further, in the loading-side load lock chamber 19, there is provided a loading wafer transfer mechanism 21 for receiving the unprocessed wafer W from the outside and transferring it to the wafer holder 14 waiting in the wafer transfer chamber 16 for unloading. Inside the side load lock chamber 20, a carry-out wafer transfer mechanism 22 for receiving the processed wafer W from the wafer holder 14 and transferring it to the outside is provided.

On the other hand, as shown in FIGS. 2 to 3, the gas supply unit 2 supplies the processing gas with a plurality of regions concentric with the surface of the disk-shaped wafer W, for example, a central portion, an intermediate portion and a peripheral portion. In order to divide the flow rate into three areas, E1, E2, and E3, and divide the flow rate into three concentric chambers, namely, the first, second, and third gas supply chambers R1, R2, and R3. Has been. A large number of gas supplies 23 for blowing the processing gas in a shower shape are formed on the lower surfaces of the gas supply chambers R1, R2, R3, and have a so-called shower head structure. The lower surfaces of the gas supply chambers R1, R2, R3 are preferably formed in a horizontal plane parallel to the wafer W, but may be formed in a curved surface.

The gas supply chambers R1, R2, R3 have a predetermined area ratio for increasing the processing gas in the radial direction from the center with respect to the surface of the wafer W, for example, 0.5 to 1.5 to 2.0 to 4. 0
An area ratio of 4.0 to 6.0, preferably an area ratio of 1: 3: 5, is divided into a plurality of concentric regions so that the same flow rate as the area ratio can be supplied. For example, for a 12-inch wafer with a diameter of 300 mm, the radius is 5
It is preferable that the area ratio be obtained by dividing into 3 equal parts at 0 mm intervals. Gas supply pipes P1, P2, P3 made of, for example, quartz are connected to the gas supply chambers R1, R2, R3, respectively, and the gas supply pipes P1, P2, P3 are connected to flow rate controllers C1, C2, C3 and switching. It is connected to a processing gas supply source or an inert gas supply source via a valve.

Next, the operation and the heat treatment method of the heat treatment apparatus configured as described above will be described. First, the wafer holder 14 is lowered into the wafer transfer chamber 16, the upper and lower shutters S1 and S2 are closed, the inside of the reaction tube 1 is replaced with an inert gas, and a predetermined heat treatment area is subjected to a predetermined treatment by the heating unit 4. It should be in a state of being heated to the temperature.

In this state, first, the wafer W before being processed is loaded by the loading wafer transfer mechanism 21 into the load lock chamber 1 on the loading side.
When the wafer W is transferred to the wafer holder 14 via
Is moved up and down by a lifting mechanism 12 to a predetermined temperature region (heat treatment region) above the reaction tube 1. At that time, the lower shutter S2 and the upper shutter S1 are sequentially opened and closed to allow the upward movement of the wafer W and the wafer holder 14.

Further, when starting the upward movement of the wafer W, the gas supply source is switched from the inert gas to the processing gas, and the processing gas is supplied with the flow rate controllers C1, C2, C3 and the gas supply pipes P1, P2, P3. Is supplied to each of the gas supply chambers R1, R2, R3 of the gas supply unit 2 via the gas supply chambers R1, R2, R3.
2, the processing gas is supplied downward from the R3 gas supply hole 23 in the reaction tube 1. Then, when the wafer W is at a low position in the reaction tube 1, the center side flow rate (for example, the gas flow rate from the first and second gas supply chambers R1 and R2) is changed to the peripheral side flow rate (for example, from the third gas supply chamber R3). Gas flow rate), so that the center side flow rate is the same as the peripheral side flow rate when the wafer W is in the intermediate position in the reaction tube 1, and the center side flow rate is the peripheral side flow rate when the wafer W is in the high position in the reaction tube 1. According to the height when the wafer W is moved up from the low position to the high position which is the heat treatment area, such as decreasing the flow rate, the flow rate controller C1,
The flow rate of the processing gas is adjusted by C2 and C3.

If the wafer W is held in a predetermined heat treatment area, the processing gas is increased in a radial direction from the center with respect to the surface of the wafer W at a predetermined area ratio, for example, 1: 3 :.
At 5, a plurality of concentric regions E1, E2, E3 are divided and supplied at the same flow rate ratio as the area ratio to perform heat treatment. In this case, the first, second and third gas supply chambers R1, R2, R3
Therefore, the flow rate is adjusted by the flow rate adjusters P1, P2, P3 so that the processing gas is supplied at the above flow rate ratio. The process gas flow rate adjustment by the flow rate adjusters C1, C2, C3 may be manual, but it is preferable that the flow rate adjusters C1, C2, C3 are automatically adjusted according to a program preset by the controller.

When the heat treatment of the wafer W is completed, the reaction tube 1
The inside is replaced with an inert gas, and the wafer W is transferred to the wafer transfer chamber 1
It is moved down to 6. At that time, the upper shutter S1 and the lower shutter S2 are sequentially opened and closed to block the inside of the reaction tube 1 while allowing the downward movement of the wafer W and the wafer holder 14. When the wafer holder 14 reaches the wafer transfer chamber 16, the wafer holder 14 is carried out by the carry-out wafer transfer mechanism 22.
The processed wafer W is transferred from above to the unload-side load lock chamber 20, returned to room temperature, and then unloaded to the outside. Then, the wafer holder 14 that stands by in the wafer transfer chamber 16
Then, the next wafer W is transferred from the loading-side load lock chamber 19, and the above-mentioned cycle is repeated, so that the wafers W are continuously heat-treated one by one.

In this way, the unprocessed wafer W can be quickly loaded into the reaction tube 1, and after the heat treatment for a predetermined time, the processed wafer W can be immediately unloaded from the reaction tube 1. As a result, the thermal history of the wafer W can be minimized by rapidly increasing and decreasing the temperature, so that the semiconductor element can be miniaturized.
Further, in the heat treatment, the processing gas is divided into a plurality of concentric circular regions with a predetermined area ratio increasing in the radial direction from the center with respect to the surface of the wafer W, and is supplied at the same flow rate ratio as the area ratio. Therefore, it becomes possible to sufficiently suppress the gas flow of the processing gas that is poured near the central portion of the wafer W from bouncing back near the peripheral portion of the wafer W, so that the processing film is uniformly formed on the surface of the wafer W within the surface. The film can be formed, and the heat treatment can be made highly uniform.

Moreover, in the process of moving the wafer W from the lower part to the upper heat treatment area in the reaction tube 1, the processing gas is divided into a plurality of areas concentric with the surface of the wafer W, and the peripheral side thereof. Wafer W that is closer to the center than the flow
Is large at the low position and small at the high position. Therefore, in the process of ascending the wafer W from the low position to the high position which is the heat treatment area, the amount of processing gas poured near the central portion of the wafer W is increased. It is possible to suppress the gas flow from bouncing around the peripheral portion of the wafer W, and it is possible to form a processing film on the surface of the wafer W more evenly and in-plane.

Although the embodiments of the present invention have been described in detail above with reference to the drawings, the present invention is not limited to the above embodiments, and various design changes and the like without departing from the scope of the present invention. Is possible. For example, the same kind of process gas (for example, a pre-mixed process gas) may be supplied to the gas supply chambers of the gas supply unit, or different kinds of process gas (for example, a pre-mixed process gas). May be supplied. In addition, as shown in FIG. 4, the gas supply unit has a bellmouth-shaped guide 2 for guiding the processing gas from each of the gas supply chambers R1, R2 and R3.
4 may be provided. The gas supply port in the gas supply unit preferably has a shower head structure having a large number of gas supply holes, but may have, for example, a slit shape, or may be fully opened for each gas supply chamber.

As a heat treatment apparatus to which the present invention is applied, as shown in FIG. 5, a wafer carry-in port 25 and a carry-out port 26 having gate valves G1 and G2 are formed on both sides of a processing chamber 1 made of, for example, quartz. Then, the wafer holder 1 in the processing chamber 1
Alternatively, the wafer W may be transferred directly from the horizontal direction with respect to 4. In the figure, the same parts as those in FIG. 1 are designated by the same reference numerals and the description thereof will be omitted.

As the wafer holder 14 which is a supporter of the wafer, as shown in FIG.
4a is fixed and supported, and the center of the wafer W is supported by a spring 27.
The structure may be elastically supported by a, or, as shown in FIG. 7, the peripheral portion of the wafer W may be elastically supported by a spring 27b and the central portion of the wafer W may be fixedly supported by a support rod 28. Further, as the wafer holder 14, FIG.
As shown in FIG. 9, the central portion and the peripheral portion of the wafer W may be elastically supported by springs 27a and 27b, or as shown in FIG. 9, the lower surface periphery of the wafer W is elastically supported by a plurality of springs 27a and 27b. May be

As a material for the spring, a material having heat resistance and which does not become a contamination source of the wafer, such as quartz, is used.
Ceramic, silicon carbide (SiC), etc. are applicable. Further, the shape of the spring is preferably a coil shape, but may be a lateral U shape, a bellows shape or the like.
With the structure in which a part or the whole of the lower surface of the wafer W is elastically supported by the spring as described above, the back surface of the wafer W is less likely to be scratched, cracks can be prevented, and the wafer W can be prevented. It is possible to prevent stress destruction due to bending of its own weight due to an increase in diameter.

If the wafer support is a fixed installation type susceptor, as shown in FIG.
A receiving portion 30 for receiving the peripheral portion of the wafer W is formed on the peripheral portion of the upper surface of the spring, and springs 27c, 27 for elastically supporting the central portion and the peripheral portion of the wafer W in a recess 31 formed in the central portion.
It may have a structure provided with d. In this case, the supporting height of the peripheral edge of the wafer W from the bottom surface of the recess 30 is H, the height of the central spring 27c is h1, the height of the peripheral spring 27d is h2, and H>h1> h2. Thus, the wafer W may be supported by allowing the bending of the wafer W due to its own weight within a certain allowable range.

As a susceptor, as shown in FIG. 11, a load receiving mechanism 32 including an air cylinder or the like is provided in the recess 31a instead of the spring, and the load of the wafer W in the portion which is bent in the recess 31a is detected by the load cell. However, it may be configured to correct the flexure.

As the heating means, for example, a lamp or the like can be applied in addition to the resistance heating element. As the substrate to be processed,
Besides the semiconductor wafer W, for example, an LCD substrate or the like can be applied. In addition to the oxidation, as the heat treatment, for example, C
VD, diffusion, annealing, etc. are applicable.

[0041]

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

(1) According to the first aspect of the present invention, in the heat treatment method of performing the heat treatment while supplying the processing gas perpendicularly to the surface of the substrate to be processed housed in the processing chamber, the processing gas is supplied to the substrate to be processed. Since the surface of the substrate is divided into a plurality of concentric areas and the flow rate is changed and supplied, the gas flow of the processing gas poured near the central portion of the substrate to be processed is near the peripheral portion of the substrate to be processed. It is possible to suppress the bounce and it is possible to form a treatment film uniformly on the surface of the substrate to be treated.

(2) According to the second aspect of the present invention, in the heat treatment method of performing the heat treatment while supplying the processing gas perpendicularly to the surface of the substrate to be processed housed in the processing chamber, the processing gas is supplied to the substrate to be processed. The surface area of the substrate is divided into a plurality of concentric areas with a predetermined area ratio that increases from the center in the radial direction, and the flow rate is the same as the area ratio. It is possible to sufficiently suppress the gas flow of the processing gas that bounces off near the peripheral portion of the substrate to be processed, and it is possible to form a processing film uniformly on the surface of the substrate to be processed.

(3) According to the third aspect of the invention, the processing gas is supplied downward from the upper part of the processing chamber, and the substrate to be processed is moved from the lower part to a predetermined heat treatment area so that the processing gas hits the surface vertically. In the heat treatment method of moving upward by heat treatment, the processing gas is divided into a plurality of concentric regions with respect to the surface of the substrate to be processed, and the flow rate at the center side is lower than the flow rate at the peripheral side when the process substrate is at a low position. Since the number is high and the number is low at the high position, the gas flow of the processing gas poured near the central portion of the substrate to be processed is increased in the process of moving the substrate to be processed from the low position to the high position which is the heat treatment area. It is possible to suppress the bounce around the peripheral portion of the substrate to be processed, and it is possible to form a processing film uniformly on the surface of the substrate to be processed.

(4) According to the invention of claim 4, in a heat treatment apparatus for performing heat treatment while supplying a processing gas perpendicularly to the surface of a substrate to be processed housed in the processing chamber, the processing gas is supplied to the processing chamber. Since the gas supply part that supplies different flow rates to the surface of the substrate to be processed is divided into multiple concentric regions, the gas flow of the processing gas that is poured near the center of the substrate to be processed is processed. It is possible to suppress the bounce around the peripheral portion of the substrate, and it is possible to form a processing film uniformly on the surface of the substrate to be processed.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a heat treatment apparatus according to an embodiment of the present invention.

FIG. 2 is an enlarged cross-sectional view of a processing gas supply unit in the heat treatment apparatus of FIG.

FIG. 3 is a plan view showing regions where the flow rates of processing gases supplied to the surface of a wafer are different.

FIG. 4 is an enlarged cross-sectional view showing another example of the processing gas supply unit.

FIG. 5 is a schematic sectional view showing a heat treatment apparatus according to another embodiment of the present invention.

FIG. 6 is a side view showing an example of a wafer holder.

FIG. 7 is a side view showing another example of the wafer holder.

FIG. 8 is a side view showing another example of the wafer holder.

FIG. 9 is a side view showing another example of the wafer holder.

FIG. 10 is a side view showing another example of the wafer holder.

FIG. 11 is a side view showing another example of the wafer holder.

FIG. 12 is a schematic sectional view showing a conventional heat treatment apparatus.

FIG. 13A is an explanatory view showing a gas flow in the vicinity of a surface to be processed of a wafer in a conventional heat treatment apparatus, and FIG. 13B is a state diagram of a processed film formed on the wafer.

[Explanation of symbols]

 1 Reaction Tube (Processing Room) 2 Gas Supply Section 3 Exhaust Pipe 4 Heating Section 14 Wafer Holder R1, R2, R3 Gas Supply Chamber C1, C2, C3 Flow Controller

Claims (4)

[Claims] 1. A heat treatment method of performing a heat treatment while supplying a processing gas perpendicularly to the surface of a substrate to be processed housed in a processing chamber, wherein the processing gas has a plurality of concentric regions with respect to the surface of the substrate to be processed. The heat treatment method is characterized in that the flow rate is divided and supplied at different rates. 2. A heat treatment method of performing heat treatment while supplying a processing gas perpendicularly to the surface of a substrate to be processed housed in a processing chamber, wherein the processing gas is increased in a radial direction from the center with respect to the surface of the substrate to be processed. The heat treatment method is characterized by dividing into a plurality of concentric regions at a predetermined area ratio and supplying the same flow rate ratio as the area ratio. 3. A heat treatment method in which a treatment gas is supplied from the upper portion of a treatment chamber to a lower portion, and the substrate to be treated is moved upward from a lower portion to a predetermined heat treatment region so that the treatment gas hits the surface perpendicularly to perform heat treatment. The processing gas is divided into a plurality of concentric regions with respect to the surface of the substrate to be processed, and the central side flow rate is higher than the peripheral side flow rate when the processing substrate is in the low position and is low in the high position. A heat treatment method characterized by the above. 4. A heat treatment apparatus for performing a heat treatment while supplying a processing gas perpendicularly to the surface of a substrate to be processed housed in the processing chamber, wherein the processing gas is concentric with the surface of the substrate to be processed in the processing chamber. A heat treatment apparatus characterized by comprising a gas supply unit which is divided into a plurality of regions and supplies the gas at a changed flow rate.