JP2003158171A - Boat for vertical furnace - Google Patents

Abstract

PROBLEM TO BE SOLVED: To form a thin film uniformly by making uniform the temperature of a substrate or the gas supply thereto at the time of performing a specified processing of the substrate in a vertical furnace. SOLUTION: The boat 100 for a vertical furnace being used in the processing chamber of a vertical furnace performing a specified processing of a substrate comprises supporting plates 24 for mounting/supporting a substrate respectively, and columns 22 for supporting the supporting plate wherein a plurality of supporting plates are arranged in parallel and the columns are arranged perpendicularly to the plurality of supporting plates. The supporting plate 24 is provided with a plurality of supporting pins 28 for mounting/supporting a substrate, and a through hole 26 smaller than the substrate.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vertical furnace boat used in manufacturing semiconductor devices.

[0002]

2. Description of the Related Art FIG. 4 is a sectional view showing a schematic structure of a vertical furnace used in a semiconductor manufacturing process. Conventionally, in oxidation, diffusion and annealing of impurities in a semiconductor manufacturing process, and film formation of a nitride film, polysilicon or doped polysilicon by the LP-CVD method, a vertical furnace as shown in FIG. 4 is generally used. It is used.

As shown in FIG. 4, a vertical furnace 500 is provided with an inner tube 2 and an outer tube 4, and in a processing chamber 6 inside the inner tube 2, for example, L
The substrate 14 is subjected to predetermined processing such as film formation by the P-CVD method or the like.

A heater 12 is mounted on the outer side of the outer tube 4. The heater 12 is controlled so that the temperature of the substrate 14 reaches a predetermined temperature. Further, the processing gas is introduced into the processing chamber 6 from the gas introduction port 8 to the lower side, and is heated by the heater 12 while rising upward, and is decomposed on the surface of the substrate 14 by the reaction of formation and film formation. The formation takes place. The reaction-completed gas and the unreacted gas pass between the inner tube 2 and the outer tube 4 and are exhausted from the gas exhaust port 6.

FIG. 5 is a perspective view showing a schematic structure of a conventional vertical furnace boat 400. As shown in FIG. 5, the vertical furnace boat 400 is configured to support the plurality of substrates 14 by the plurality of columns 40.

FIG. 6 is a view showing a state in which the substrate is supported in the vertical furnace boat, and FIG. 6 (a) is a top view in the case of cutting in the DD ′ direction of FIG. Figure 6 (b)
6 shows a sectional view taken along the line EE ′ of FIG. As shown in FIG. 6B, the column 40 is provided with support pieces 42 in a shelf shape so that a plurality of substrates can be horizontally supported. The substrate 14 has the structure shown in FIGS.
As shown in (b), a plurality of supporting pieces 42 are supported vertically and in parallel with the columns 40 of the vertical furnace boat 400 so as to come into contact with the supporting pieces 42 at several positions.

The substrate 14 is usually a vertical furnace boat 400.
Then, a plurality of sheets are supported in parallel at a predetermined interval and inserted into the processing chamber 6. The thin film is formed on the substrate 14 by causing the gas supplied onto the substrate 14 in the processing chamber 6 to undergo decomposition and generation reactions by thermal energy from the heater. Therefore, in order to make the film thickness of the film formed on the substrate 14 uniform, it is necessary to make the amount and temperature of the supplied gas and the temperature in the processing chamber 6 uniform.

[0008]

By the way, as shown in FIG. 5, the substrate 14 is attached to the vertical furnace boat 400 by one or two.
It is possible to put 00 sheets. That is, the column 40 needs to be able to bear the weight of the substrate 14 even when 200 substrates are placed. Therefore, the pillar needs to have a certain thickness, and the heat capacity of the pillar becomes large. Therefore, even if the temperature in the processing chamber is controlled to be uniform by a heater or the like, the temperature of the substrate becomes high in the vicinity of the support piece on which the substrate is supported,
The temperature of the entire substrate becomes uneven.

As shown by the arrow in FIG. 4, the gas is supplied from the lower part of the processing chamber 6 and moves upward,
It moves horizontally to the surface of the substrate 14. That is, the gas is supplied to the substrate by diffusion from the outer periphery of the substrate. However, as described above, since the support pillars that support the substrate have a certain thickness, when the gas flows, the support pillars act as a barrier and the gas flow is disturbed, so that the gas cannot be evenly distributed on the substrate surface. Therefore, the gas supplied to the substrate surface becomes non-uniform, and the film thickness formed on the substrate becomes non-uniform.

The decomposition and generation reaction of gas for forming a thin film occurs not only on the surface of the substrate but also on the surface of the pillar. In other words, the reaction of gas occurs on the surface of the pillar,
The amount of gas supplied to the substrate is reduced near the pillar. Therefore, the thin film formed on the substrate tends to be thin near the pillar.

As described above, in order to form a uniform thin film on the substrate, it is necessary to make the temperature in the substrate and the processing chamber and the amount of gas supplied to the substrate uniform. However, due to the influence of the pillars in the processing chamber, the temperature of the substrate surface varies, and the amount of gas supplied to the substrate becomes non-uniform. Therefore, the present invention proposes to form a uniform thin film while suppressing the influence of the columns of the vertical furnace boat on the temperature of the substrate and the amount of gas supplied to the substrate.

[0012]

A vertical furnace boat according to the present invention is a vertical furnace boat used in a processing chamber of a vertical furnace for subjecting a substrate to a predetermined process. A support plate that supports the support plate, and a column that supports the support plate,
A plurality of the support plates are arranged in parallel, and the columns are arranged so as to be perpendicular to the plurality of support plates.

Further, in the vertical furnace boat of the present invention, the support plate includes a plurality of support pins for mounting and supporting the substrate.

Further, in the vertical furnace boat of the present invention, the outer periphery of the support plate is circular.

In the vertical furnace boat according to the present invention, the substrate is placed on the support plate so that the center of the substrate to be placed and the center of the support plate are aligned with each other.

Further, in the boat for vertical furnace according to the present invention, the support plate is larger than the substrate on which the support plate is placed.

Further, in the vertical furnace boat of the present invention, the support plate has a through hole smaller than the substrate on which it is mounted.

In the vertical furnace boat of the present invention, the through hole is circular.

Further, in the boat for vertical furnace according to the present invention, the support plate has a through hole larger than the outer circumference of the substrate, and the through hole has a plurality of protrusions for supporting the substrate to be placed. It is a thing.

Further, in the boat for vertical furnace according to the present invention, the support column supports the support plate inside the outer periphery of the support plate.

Further, in the boat for vertical furnace according to the present invention, when the substrate is placed on the support plate, the columns are arranged so as to have a predetermined distance from the substrate.

[0022]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. In the drawings, the same or corresponding parts are designated by the same reference numerals, and the description thereof will be omitted or simplified.

Embodiment 1. 1 is a sectional view showing a schematic configuration of a vertical furnace used in Embodiment 1 of the present invention. In FIG. 1, reference numeral 100 indicates a vertical furnace boat, and reference numeral 200 indicates a vertical furnace.

Reference numeral 2 is an inner tube, and reference numeral 4 is
An outer tube, reference numeral 6 indicates a processing chamber. Both the inner tube 2 and the outer tube 4 are made of quartz or SiC. The processing chamber 6 is a portion for performing a predetermined processing on the substrate inside the inner tube 4.

Reference numeral 8 indicates a gas inlet, and reference numeral 10 indicates a gas outlet. The gas inlet 8 penetrates both the outer tube 4 and the inner tube 2 to allow gas to flow into the lower portion of the processing chamber 6. The gas discharge port 10 penetrates the outer tube 4 and discharges gas from the lower portion between the inner tube 2 and the outer tube 4.

Reference numeral 12 indicates a heater. Heater 1
Reference numeral 2 is a spirally wound heater wire such as a Kanthal wire, which is mounted outside the outer tube 4. The heater is 400 to 12 inside the processing chamber.
It can be controlled to a predetermined temperature of 00 ° C.

A vertical furnace 20 including an inner tube 2, an outer tube 4, a processing chamber 6, a gas inlet 8, a gas outlet 10, a heater 12 and a vertical furnace boat 100.
0 is configured.

FIG. 2 is a diagram showing a schematic structure of a vertical furnace boat 100 used in the first embodiment of the present invention, and FIG. 2 (a) is a sectional view taken along the line AA 'in FIG. 2B is a cross-sectional view taken along the line BB ′ of FIG. 2A.

In FIGS. 2A and 2B, reference numeral 14 indicates a substrate. However, in FIG. 2A, for the sake of explanation, only the outer peripheral line of the substrate 14 is shown and the inside is seen through.

Reference numeral 22 indicates a support, and reference numeral 24 indicates a support plate. Both the column 22 and the support plate 24 are made of quartz or SiC. The outer periphery 24 of the support plate has a circular shape, and four columns 22 are provided near the outer periphery of the support plate 24 at equal intervals to support the support plate 24. Post 22
Each vertically penetrates the 200 support plates 24,
The support plate 24 is supported inside each support plate 24. Further, the support column 22 is arranged at a position away from the outer peripheral portion of the substrate 14 placed on each support plate 24 by a distance d. In this embodiment, the distance d is larger than the diameter of the support column 22. That's it. Therefore, when the substrate 14 is placed on the support plate 24, the substrate 14 and the support column 22 can be provided with a sufficient distance.

Reference numeral 26 indicates a through hole. Through hole 26
Is a part where the support plate 24 is hollowed out, and has a circular shape concentric with the support plate 24. Therefore, the support plate 24 has a donut shape. Support plate 24 for substrate 14
The outer circumference circle has a large diameter and the through hole 26 has a small diameter.

Reference numeral 28 indicates a support pin. Support pin 2
8 is made of quartz or SiC. The support pins 28 are provided when the substrate 14 is placed on each support plate 24.
Four pieces are evenly provided so as to project in a portion in contact with the substrate 14. The support pins 28 support the substrate 14 in a state of point contact from the back surface in the state shown in FIG. 2B.

It should be noted that the vertical furnace boat 1 includes the columns 22, the 200 support plates 24, the through holes 26, and the support pins 28.
00 is configured. The vertical furnace boat 100 is used by inserting it into the vertical furnace 200 as described above.

Next, the vertical furnace boat 100 and the vertical furnace 2
The operation of 00 will be described below. First, the substrate 14 is loaded into the vertical furnace boat 100. By mounting the substrate 14 on the support pins 28 of each support plate 24, each support plate 24 horizontally supports the substrate 14. by this,
The substrate 14 is loaded into the vertical furnace boat 100. The vertical furnace boat 100 is provided with 200 supporting plates 24, and one substrate can be loaded on each supporting plate 24, up to a total of 200 substrates at once. Therefore, the required number of substrates may be placed on each support plate 24 as needed.

On the other hand, a processing gas is introduced into the vertical furnace 200 through the gas inlet port 8, and the heater 12 heats the gas to a predetermined temperature and causes the gas to flow into the processing chamber 6 so that the inside of the processing chamber 6 is filled. Fill with processing gas. At the same time, the inside of the processing chamber 6 is warmed by the heater 12, and the inside of the processing chamber 6 is heated to 4
The temperature is controlled to a predetermined temperature of 00 to 1200 ° C.

In this state, the vertical furnace boat 100 on which the substrate 14 is placed is inserted into the processing chamber 6. Even after the vertical furnace boat 100 is inserted, the processing chamber 6 is continuously filled with the processing gas through the gas introduction port 8. The processing gas supplied from the gas inlet 8 to the lower part of the processing chamber 6 moves upward while being heated from the outside by the heater 12, as indicated by the arrow in FIG. And flows from the outer circumference of the substrate 14 to the surface of the substrate. On the surface of the substrate 14, the gas thus supplied reacts to form a thin film. The reacted gas and unreacted gas are exhausted from the gas exhaust port 10.

In this way, the column 2 having a large heat capacity
It is possible to perform the treatment in a state in which 2 is separated from the substrate to some extent. Therefore, even if the gas reacts on the surface of the support column 22, the influence on the gas supply amount to the substrate 14 can be reduced, so that the film formed on the substrate near the support column 24 is prevented from becoming thin. be able to.

At the same time, since the column 22 and the substrate 14 are sufficiently separated from each other, even if the gas flow is obstructed by the column 22, the influence on the substrate 14 is small. Therefore, the gas can be supplied to the substrate 14 uniformly to some extent, and a uniform thin film can be formed.

Further, since the column 22 having a large heat capacity and the substrate can be separated from each other, it is possible to suppress variation in temperature near the substrate 14 and to form a uniform thin film.

In the first embodiment, the substrate 14 is supported from the back surface by the support pins 28 in a point contact state. Therefore, the support plate 24 having a specific heat different from that of the substrate 14
Alternatively, the support pins 28 can prevent the temperature of the substrate 14 from varying, and can form a uniform thin film.

In this embodiment, the vertical furnace 200 generally used for forming a thin film by the LP-CVD method.
The vertical furnace boat 100 was used for the above. However, the vertical furnace boat 100 is not limited to such a vertical furnace, and may be used for other vertical furnaces.

Further, in this embodiment, the vertical furnace boat 100 is provided with 200 support plates 24 so that up to 200 substrates can be loaded at one time. However, the present invention is not limited to this, and an appropriate number of support plates may be provided in consideration of the strength of the column, the processing efficiency, and the like.

Further, in this embodiment, the support column 22 is
The size of the support plate 24 is determined so that the outer periphery of the substrate 14 and the distance d that is equal to or larger than the diameter of the support column 22 can be determined.
2 was placed. This is to prevent the amount of gas supplied to the substrate 14 from becoming non-uniform due to the support 22 serving as a barrier as described above. But not necessarily
It is not limited to those having a distance equal to or larger than the diameter of the column 22.

Further, in this embodiment, the support column 22 is arranged so as to be supported inside the support plate 24. This is to make the overall shape of the vertical furnace boat 100 into a symmetrical shape such as a cylinder so as to evenly affect the temperature and the gas flow by the columns, and to supply the amount of gas to the substrate and the temperature of the substrate. This is to measure the homogenization of. However, it is not limited to this,
The support pillar may support the substrate from the outside of the support plate.

Further, in this embodiment, as described above, four columns 22 and four support pins 28 are provided. This is because the struts 22 have a symmetrical shape.
Or a reaction with a gas that occurs on the surface of the support plate 24,
This is to make the barrier against the gas flow uniform, and thereby to make the temperature of the substrate 14 and the amount of gas supplied to the substrate uniform. However, if the temperature of the substrate and the amount of gas supplied to the substrate can be made uniform in consideration of the force required to support the support plate and the substrate, the number of columns and support pins is four. It is not limited to individual pieces.

Further, in this embodiment, the support column 22, the support plate 24, and the support pin 24 are made of quartz, SiC or the like, but the present invention is not limited to this.

Further, in this embodiment, the support plate 24
In order to facilitate loading and unloading of the substrate 14, a circular plate was formed into a donut shape in which concentric circles were hollowed out. But,
It is not necessarily limited to this shape.

Embodiment 2. FIG. 3 is a view showing a conceptual configuration of a vertical furnace boat used in Embodiment 3 of the present invention, and FIG. 3 (a) is a top view when cut along the line AA ′ in FIG. FIG. 3B shows a sectional view taken along the line CC ′ of FIG. In FIG. 3, reference numeral 300
Shows a vertical furnace boat used in the second embodiment. Further, in the second embodiment, the vertical furnace is the same as in the first embodiment.
Use the same one used in.

Reference numeral 30 indicates a through hole, and reference numeral 32 indicates a protruding portion. The through hole 30 is a portion where the support plate 24 is hollowed out. Further, the reference numeral 30 has a substantially circular shape which is concentric with the support plate 24, but the projecting portions 32 are provided at four positions. The diameter of the through hole 30 is larger than the diameter of the substrate,
When the substrate 14 is placed, the substrate contacts and is supported only by the protrusion 32. Further, the protrusion 32 is provided with a support pin 28, and
The substrate is supported in a state like the point contact shown in (b).
Since the other parts are the same as those in the first embodiment, the description thereof will be omitted.

By doing so, the area of the supporting plate 24 near the substrate 14 having a specific heat different from that of the substrate can be reduced. Therefore, the support plate 24 can prevent the supply amount of gas to the substrate and the temperature in the vicinity of the substrate from becoming non-uniform, and a more uniform thin film can be formed.

Here, the support plate 30 is provided with four protrusions 32. This is because the support plate 30 has a symmetrical shape so that the influence on the temperature of the substrate and the amount of gas supplied to the substrate is equalized. However, the number of protrusions is not limited to four as long as the force for supporting the substrate and the influence on the temperature of the substrate are taken into consideration.

[0052]

As described above, according to the present invention, the substrate is supported by the supporting plate. Therefore, as compared with a case in which the substrate is supported by a support piece directly provided on the support, the support can suppress the influence of the support on the temperature of the substrate and the amount of gas supplied to the substrate, and can form a uniform thin film. .

Further, in the present invention, the support plate has a circular outer periphery, the center of the circular support plate and the center of the substrate are arranged at the same position, and the support plate is protruded from the inside of the support plate. For those that have pillars so that they do not exist, the shape inside the processing chamber can be made symmetrical,
It is possible to equalize the influence of the support plate and the support on the temperature of the substrate and the amount of gas supplied to the substrate. Therefore, the temperature of the substrate and the amount of gas supplied to the substrate can be kept constant to form a more uniform thin film.

Further, in the present invention, in the case where the substrate is supported by the support pins, the contact area between the substrate and the support plate having a different specific heat can be made small.
Variations in the temperature of the substrate and the amount of gas supplied to the substrate can be suppressed, and a uniform thin film can be formed.

In the present invention, the support plate has a diameter larger than that of the substrate, and the support plate can be placed on the support plate with a space between the support column and the support plate. The influence on the temperature and the amount of gas supplied to the substrate can be reduced, and a more uniform thin film can be formed.

In the case where the substrate is supported by the protruding portion protruding into the through hole, the area of the supporting plate having a specific heat different from that of the substrate can be reduced, so that variations in the temperature of the substrate and the amount of gas supplied to the substrate can be prevented. It can be suppressed and a uniform thin film can be formed.

Further, in the present invention, with respect to the support plate having the through holes, the substrate can be easily attached and detached.

[Brief description of drawings]

FIG. 1 is a sectional view showing a schematic configuration of a vertical furnace used in a first embodiment of the present invention.

FIG. 2 is a diagram showing a schematic configuration of a vertical furnace boat used in the first embodiment of the present invention.

FIG. 3 is a diagram showing a conceptual configuration of a vertical furnace boat used in a third embodiment of the present invention.

FIG. 4 is a cross-sectional view showing a schematic configuration of a known vertical furnace used in a semiconductor manufacturing process.

5 is a perspective view showing a schematic configuration of a conventional vertical furnace boat 400. FIG.

FIG. 6 is a diagram showing a state in which a substrate is supported in a vertical furnace boat.

[Explanation of symbols]

100, 300, 400 Vertical furnace boats 200, 500 Vertical furnace 2 Inner tube 4 outer tube 6 processing room 8 gas inlets 10 gas outlet 12 heater 14 board 22 props 24 Support plate 26 through holes 28 Support pins 30 through holes 32 protrusion 40 props 42 Support piece

Claims (10)

[Claims] 1. A boat for a vertical furnace used in a processing chamber of a vertical furnace for subjecting a substrate to a predetermined process, comprising: a support plate for mounting and supporting the substrate; and a column for supporting the support plate. A plurality of the support plates are arranged in parallel, and the columns are arranged so as to be perpendicular to the plurality of support plates. 2. The boat for a vertical furnace according to claim 1, wherein the support plate includes a plurality of support pins for mounting and supporting a substrate. 3. The boat for a vertical furnace according to claim 1, wherein an outer periphery of the support plate has a circular shape. 4. The substrate is placed on the support plate so that the center of the substrate to be placed and the center of the support plate are aligned with each other. The vertical furnace boat described in. 5. The boat for a vertical furnace according to claim 1, wherein the support plate is larger than a substrate on which the support plate is placed. 6. The boat for a vertical furnace according to claim 1, wherein the support plate has a through hole smaller than a substrate on which the support plate is placed. 7. The boat for a vertical furnace according to claim 6, wherein the through hole has a circular shape. 8. The support plate has a through hole larger than the outer circumference of the substrate, and the through hole has a plurality of protrusions for supporting the substrate to be placed. 5. The vertical furnace boat according to any one of 5 above. 9. The boat for a vertical furnace according to claim 1, wherein the support column supports the support plate inside the outer periphery of the support plate. 10. The support according to claim 1, wherein the support column is arranged so as to have a predetermined distance from the substrate when the substrate is placed on the support plate. Vertical furnace boat.