JP2022095138A - Susceptor, substrate processing device, and substrate processing method - Google Patents

Abstract

To provide a susceptor, a substrate processing device, and a substrate processing method which can prevent a decrease in work efficiency due to a lid material, can stably and continuously hold a substrate, and do not easily generate an undeposited region on the outer peripheral portion of the substrate.SOLUTION: A susceptor 100 that includes a substrate mounting portion 101 on which a substrate 1 is mounted on a flat surface portion 101a and the diameter of the outer periphery of the flat surface portion is equal to or larger than the outer diameter of the substrate, and a peripheral portion 102 composed of a wall portion 102a extending vertically from the outer peripheral edge of the flat surface portion and an upper surface 102b extending horizontally from the upper end of the wall portion toward the outside of the flat surface portion, and a ring-shaped eaves 103 is provided at the upper end of the wall portion 102a of the peripheral edge 102 so as to horizontally project from the upper surface 102b toward the inside of the flat surface, and the vertical length between the flat surface portion side end portion 103b and the flat surface portion 101a of the ring-shaped eaves is greater than the thickness of the substrate.SELECTED DRAWING: Figure 1

Description

The present invention relates to a susceptor, a substrate processing apparatus and a substrate processing method, and uses, for example, a substrate processing apparatus capable of forming an epitaxial film of silicon carbide (SiC), a susceptor capable of being provided in the substrate processing apparatus, and the susceptor. Regarding improvement of substrate processing method.

Silicon carbide (SiC) is a compound semiconductor material composed of silicon (Si) and carbon (C). Not only is SiC superior in insulation breakdown electric field strength 10 times that of Si and bandgap 3 times that of Si, but also p-type and n-type control required for device fabrication is possible over a wide range. , Is expected as a material for power devices that exceeds the limit of Si.

Further, since silicon carbide can obtain a high withstand voltage even with a thinner thickness, it is characterized in that a semiconductor having a small ON resistance and a low loss can be obtained by making it thin.

In a film forming apparatus such as an epitaxial growth apparatus used in the epitaxial growth technique for silicon carbide, for example, a wafer is placed inside a film forming chamber held at normal pressure or reduced pressure. Then, while heating the wafer, when a gas as a raw material for film formation (hereinafter, may be abbreviated as "raw material gas") is supplied to the film forming chamber, a thermal decomposition reaction of the raw material gas occurs on the surface of the wafer. A hydrogen reduction reaction occurs and an epitaxial film is formed on the wafer (for example, Patent Document 1). Further, in order to stably produce an epitaxial wafer with a high yield, it is necessary to bring new raw material gases into contact with the surface of the uniformly heated wafer one after another to improve the rate of vapor phase growth. Therefore, the wafer is epitaxially grown while being rotated at high speed.

By the way, when an epitaxial film is formed on a wafer by using the SiC epitaxial growth apparatus 1000 shown in FIG. 8, conventionally, after the substrate (for example, a wafer) 1 is housed in the substrate mounting portion 11 of the susceptor 10, the film forming chamber 1100 The susceptor 10 is placed on the upper end of the cylindrical rotary stage 1400 provided in the above. Therefore, not only the SiC film was formed on the wafer, but also the SiC film was deposited on the front surface of the susceptor 10 holding the wafer. The susceptor in which the SiC film is deposited on the front surface may be deformed due to the difference in the coefficient of thermal expansion between the front surface portion and the back surface portion on which the SiC film is not deposited. When this deformation occurs, the wafer cannot be stably held and cannot rotate at high speed.

Further, by repeating the epitaxial film formation process of SiC in the apparatus, SiC continues to be formed and deposited on the front surface of the susceptor 10, which is shown in FIG. 9 in the surface of the substrate mounting portion 11 of the susceptor 10. Protrusions or steps made of silicon carbide 400 may be formed. Then, the susceptor 10 cannot stably hold the housed substrate (wafer) 1 due to the generated step or protrusion, and the wafer is detached from the susceptor 10 due to the rotation of the susceptor 10 at the time of film formation. If the wafer is detached from the susceptor 10, the wafer may be damaged or the damaged wafer may remain in the film forming chamber, which contributes to particles at the time of film formation.

Hereinafter, the SiC epitaxial film forming process will be specifically described. First, the wafer to be filmed is housed in the substrate mounting portion of the susceptor, and the susceptor containing the wafer is the upper end of the rotary stage in the film forming chamber in the epitaxial growth apparatus. It is placed in. Then, at the time of film formation, the susceptor placed on the upper end of the rotating stage is rotated, and the raw material gas is sprayed onto the wafer to grow epitaxially, and the film formation proceeds.

When the film forming process is repeated, SiC is deposited in addition to the wafer due to the influence of the reaction of the raw material gas. In particular, there is a large amount of SiC deposited on the front surface of the susceptor, and as the deposition progresses, the deposited SiC in the surface of the substrate mounting portion where the wafer is housed becomes a step, which can stably hold the wafer. It can be difficult. During film formation by epitaxial growth, it is necessary to rotate the wafer and then spray the raw material gas in order to perform stable film formation. For this reason, if the wafer becomes an unstable holding state due to the influence of the step generated on the substrate mounting portion of the susceptor, the wafer may pop out from the susceptor by rotating the susceptor, and as a result of the popping out, the wafer may be damaged. It may end up.

Therefore, it is ideal to suppress the adhesion of SiC to the susceptor, but it is structurally difficult to control the supply of the raw material gas only to the wafer because the wafer is held by the susceptor. Further, although it is conceivable to change the temperature of only the susceptor to suppress the adhesion of SiC, it is difficult to suppress the influence of heat conduction on the susceptor, and in reality, it is difficult to prevent the film formation on the susceptor.

Therefore, it is preferable to periodically remove the SiC adhering to the susceptor so that the wafer can be stably held, but the SiC is a very hard substance and the SiC adhering to the susceptor cannot be easily removed. .. Further, even if SiC is removed, a great deal of cost and time will be required. Therefore, it is not preferable to increase the frequency of removing SiC adhering to the susceptor.

Under such a technical background, the present inventor has a substrate holder capable of suppressing the formation and deposition of silicon carbide on a susceptor and stably and continuously holding a substrate (for example, a wafer). We have already proposed a substrate processing apparatus including a substrate holder and a substrate processing method using the substrate holder (see Patent Document 2).

That is, in the substrate holder capable of stably and continuously holding the substrate, as shown in FIG. 10, the substrate 1 to be processed is placed on the flat surface portion 11a, and the diameter of the outer periphery of the flat surface portion 11a is the substrate 1. A substrate mounting portion 11 having an outer diameter equal to or larger than that of the above, a wall portion 12a that surrounds the substrate mounting portion 11 and extends in the vertical direction from the outer peripheral end of the flat surface portion 11a, and the flat surface portion 11a from the upper end of the wall portion 12a. A susceptor 10 having a peripheral surface portion 12 composed of an upper surface portion 12b extending horizontally in the outward direction, and a susceptor mounted on the upper surface portion 12b of the peripheral edge portion 12 in the susceptor 10 and facing the flat surface portion 11a of the substrate mounting portion 11. It was characterized by including a lid material 20 provided with an opening 20a at a portion. In FIG. 10, reference numeral 30 indicates a fixing means such as a screw for fixing the lid material 20 to the susceptor 10.

When the substrate holder is placed on the upper end of the rotary stage 1400 of the SiC epitaxial growth apparatus 1000 shown in FIG. 11 and the SiC epitaxial film formation treatment is performed, the SiC film formation on the susceptor 10 is performed by the action of the lid material 20. Since the deposition is suppressed, the substrate 1 can be stably and continuously held, and the life of the susceptor 10 can be extended without the need for SiC removal work, so that the susceptor 10 can be used repeatedly. It will be possible. Therefore, it has an effect of being able to provide a substrate holder, a substrate processing apparatus, and a substrate processing method capable of stably forming a film by epitaxial growth of SiC at low cost and for a long period of time. In FIG. 11, reference numeral 12c indicates a plurality of protrusions provided on the back surface side of the substrate mounting portion 11 of the susceptor 10, and the protrusions are respectively locked to the inner wall surface of the cylinder of the rotary stage 1400. The substrate holder is fixedly placed on the upper end of the rotary stage 1400.

Japanese Unexamined Patent Publication No. 2018-046149 Japanese Patent Application No. 2019-230377

However, as a result of continuous research and improvement by the present inventor, it has been found that there is room for further improvement in the substrate holder according to Patent Document 2 in which the lid material 20 is attached to the susceptor 10.

That is, in the substrate holder, as shown in FIG. 10, the lid material 20 is installed so as to cover the outer peripheral portion of the upper surface of the substrate 1, so that the flow of the raw material gas supplied from the upper side of the substrate 1 is a lid. It was confirmed that the raw material gas was difficult to reach the outer peripheral portion of the substrate 1 due to being blocked by the material 20, and an undeposited region having a width of 1 mm or more may be formed on the outer peripheral portion of the substrate 1. Further, in the above-mentioned substrate holder, it is necessary to mount (accommodate) the substrate 1 on the substrate mounting portion 11 of the susceptor 10 and then attach the lid material 20 by using a fixing means 30 such as a screw. Since it is necessary to remove the lid material 20 from the susceptor 10 after the epitaxial film formation process, it has been confirmed that the work efficiency is lowered.

The present invention has been made by paying attention to such a problem, and the problems thereof are the problem of the susceptor according to Patent Document 1 (the problem that the SiC film is easily deposited on the front surface of the susceptor) and the problem. , A susceptor, a substrate processing apparatus, and a substrate processing method for solving the problem of the substrate holder according to Patent Document 2 composed of the susceptor and the lid material (the problem that an undeposited region is likely to occur and the work efficiency is lowered). To provide.

That is, the first invention according to the present invention is
A substrate mounting portion on which the substrate to be processed is mounted on a flat surface portion and the diameter of the outer periphery of the flat surface portion is equal to or larger than the outer diameter of the substrate, and a substrate mounting portion surrounding the substrate mounting portion and perpendicular to the outer peripheral edge of the flat surface portion. In a susceptor having a peripheral edge portion composed of a wall portion extending in a direction and an upper surface extending horizontally from the upper end of the wall portion toward the outside of the flat surface portion.
A ring-shaped eaves portion is provided at the upper end of the wall portion of the peripheral edge portion so as to horizontally project from the upper surface of the peripheral edge portion toward the inside of the flat surface portion, and the diameter of the opening in the ring-shaped eaves portion is equal to or larger than the outer diameter of the substrate. Moreover, the length in the vertical direction between the flat portion side end portion of the ring-shaped eaves portion and the flat surface portion is larger than the thickness of the substrate.

Further, the second invention according to the present invention is
In the susceptor according to the first invention,
The difference between the diameter of the outer circumference of the flat surface portion and the outer diameter of the substrate is 1.0 mm to 1.4 mm.
The third invention is
In the susceptor according to the second invention,
The difference between the diameter of the opening in the ring-shaped eaves and the outer diameter of the substrate is 0.4 mm to 0.6 mm.
The fourth invention is
In the susceptor according to any one of the first invention to the third invention,
The ring-shaped eaves are characterized in that the thickness is 0.5 mm or less.
The fifth invention is
In the susceptor according to any one of the first to fourth inventions.
The length between the end of the ring-shaped eaves on the flat surface side and the upper surface of the substrate placed on the flat surface is 0.3 mm or less in the vertical direction.

Next, the sixth invention according to the present invention is
In the board processing equipment
The susceptor according to any one of the first to fifth inventions is provided.
The seventh invention is
In the substrate processing apparatus according to the sixth invention.
It is characterized by being a film forming apparatus that deposits a film on the above substrate by a chemical vapor deposition method.
The eighth invention is
In the substrate processing apparatus according to the seventh invention,
A cylindrical rotating stage on which a susceptor is placed is provided in the film forming chamber of the film forming apparatus, and a protrusion on the back surface side of the substrate mounting portion of the susceptor according to any one of the first to fifth inventions. The susceptor is fixed to the rotary stage by fitting the protrusion of the susceptor into the concave portion provided at the upper end of the cylindrical shape of the rotary stage.

Further, the ninth invention according to the present invention is
In the board processing method
The substrate holding step of holding the substrate in the susceptor according to any one of the first to fifth inventions,
After the substrate holding step, a processing step of processing the substrate while rotating the susceptor, and a processing step of processing the substrate.
Characterized by having
The tenth invention is
In the substrate processing method according to the ninth invention,
The processing step is characterized in that it is a film forming step of forming a film on the substrate.

According to the susceptor of the present invention
A ring-shaped eaves that horizontally project from the upper surface of the peripheral surface toward the inside of the flat surface is provided, and the action of the ring-shaped eaves suppresses the formation and deposition of silicon carbide on the susceptor, thus making the substrate stable. Since it is possible to continuously hold the susceptor and the life of the susceptor can be extended without the need for removing silicon carbide, the susceptor can be used repeatedly, and the substrate may pop out from the susceptor. It can be prevented by the action of the ring-shaped eaves.

Further, the length in the vertical direction between the flat portion side end portion of the ring-shaped eaves portion and the flat surface portion is larger than the thickness of the substrate, and the flow of the raw material gas supplied from the upper side of the substrate is caused by the ring-shaped eaves portion. Since it is not hindered, an undeposited region is not generated on the outer peripheral portion of the substrate, and further, since a lid material is not used as a constituent member, it is possible to prevent a decrease in work efficiency due to the lid material.

Therefore, it is possible to provide a susceptor, a substrate processing apparatus, and a substrate processing method capable of stably forming a film by epitaxial growth of silicon carbide at low cost and for a long period of time.

1 (a) is a structural cross-sectional view of the susceptor according to the present invention, and FIG. 1 (b) is a plan view of the susceptor. The schematic perspective view of the susceptor which concerns on the modification of this invention which has a plurality of substrate mounting parts. FIG. 3 (a) is a structural cross-sectional view of a susceptor according to a modified example of the present invention in which a protrusion is provided on the back surface side of the substrate mounting portion, and FIG. 3 (b) is a chemical vapor deposition method using the susceptor. FIG. 6 is a structural cross-sectional view of a film forming apparatus (epitaxial growth apparatus) for forming a film on a substrate. The explanatory view which shows the flow of the raw material gas supplied from the upper side of the substrate (wafer) placed on the susceptor which concerns on this invention. Explanatory drawing which shows the dimension of the susceptor which concerns on this invention. The graph which shows the number of times of the substrate popping out per cumulative film formation amount. The graph which shows the influence on the film thickness which the difference in the thickness of the lid material 20 of the substrate holder which concerns on Patent Document 2 has. FIG. 3 is a structural cross-sectional view of a film forming apparatus (epitaxial growth apparatus) for forming a film on a substrate by a chemical vapor deposition method using a susceptor according to a conventional example. Schematic cross-sectional view showing a state in which a substrate (wafer) is placed on a susceptor according to a conventional example to which silicon carbide is attached. FIG. 3 is a structural cross-sectional view of a substrate holder according to Patent Document 2 in which a lid material is attached to a susceptor. FIG. 3 is a structural cross-sectional view of a film forming apparatus (epitaxial growth apparatus) for forming a film on a substrate by a chemical vapor deposition method using a substrate holder according to Patent Document 2.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. However, the present invention is not limited to the embodiments.

1. 1. Suceptor As the susceptor according to the present invention, the susceptor 100 shown in FIG. 1 is exemplified, FIG. 1 (a) is a structural sectional view of the susceptor 100, and FIG. 1 (b) is a plan view of the susceptor 100.

First, as shown in FIG. 1A, the susceptor 100 is composed of a substrate mounting portion 101, a peripheral edge portion 102, and a ring-shaped eaves portion 103.

That is, the susceptor 100 according to the present invention includes a substrate mounting portion 101 on which the substrate 1 to be processed is mounted on the flat surface portion 101a and the diameter of the outer periphery of the flat surface portion 101a is equal to or larger than the outer diameter of the substrate 1. A peripheral edge portion 102 that surrounds the mounting portion 101 and is composed of a wall portion 102a that extends vertically from the outer peripheral end of the flat surface portion 101a and an upper surface 102b that extends horizontally from the upper end of the wall portion 102a toward the outside of the flat surface portion 101a. It is composed of a ring-shaped eaves 103 provided at the upper end of the wall portion 102a of the peripheral edge portion 102 and horizontally projecting from the upper surface 102b of the peripheral edge portion 102 toward the inside of the flat surface portion 101a.

The flat surface portion 101a of the substrate mounting portion 101 has a circular shape recessed from the upper surface portion 102b of the peripheral edge portion 102, and the upper surface portion 102b has a flat surface shape having a predetermined width. Further, the diameter of the opening 103a in the ring-shaped eaves 103 is set to be equal to or larger than the outer diameter of the substrate 1 so that the substrate 1 can be accommodated in the flat surface portion 101a of the substrate mounting portion 101, and has a ring shape. The vertical length between the flat surface portion 101a side end portion 103b of the eaves portion 103 and the flat surface portion 101a is such that the flow of the raw material gas supplied from the upper side of the substrate 1 is not obstructed by the ring-shaped eaves portion 103. Therefore, the thickness is set to be larger than the thickness of the substrate 1.

When the substrate 1 is placed on the flat surface portion 101a of the substrate mounting portion 101 and the susceptor 100 is rotated, the wall portion 102a of the peripheral edge portion 102 and the ring-shaped eaves portion 103 on the side surface of the substrate 1 become the substrate 1. It can play a role in preventing slippage and popping out.

Further, examples of the susceptor according to the present invention include a susceptor 200 having a plurality of substrate mounting portions 201 shown in FIG. 2, in addition to the susceptor 100 shown in FIG. It can be placed on the portion 201a. Similar to the susceptor 100, the susceptor 200 has a diameter of the outer circumference of the flat surface portion 201a equal to or larger than the outer diameter of the substrate, and the wall portion 202a extending in the vertical direction from the outer peripheral end of the flat surface portion 201a and the outer side of the flat surface portion 201a from the upper end of the wall portion 202a. It has a peripheral edge portion 202 including an upper surface portion 202b extending horizontally in the direction and a ring-shaped eaves portion (not shown). Further, the flat surface portion 201a of the substrate mounting portion 201 has a circular shape recessed from the upper surface portion 202b of the peripheral edge portion 202, and the upper surface portion 202b has a flat surface shape having a predetermined width. Further, as the susceptor according to the present invention, there is a susceptor 300 provided with a plurality of protrusions 304 on the back surface side of the substrate mounting portion 301 shown in FIG. 3 (a), and the rotary stage 1400 shown in FIG. 3 (b). The susceptor 300 may be fixed to the rotary stage 1400 by fitting the protrusion 304 into the recess 1401 provided at the upper end of the tubular shape. The number of protrusions 304 is preferably 3 or more so that the susceptor 300 is stably fixed to the rotary stage 1400.

As the susceptors 100, 200, and 300, for example, when used in a SiC epitaxial growth apparatus, a carbon susceptor can be used. Further, in the case of other uses, a susceptor made of a material suitable for each use can be used.

The substrate to be processed may be, for example, a disk-shaped wafer, but is not particularly limited, and may be a plate on which parts or the like for realizing some function can be arranged.

2. 2. Examples of Use of Suceptor 300 (1) Hereinafter, examples of use of Suceptor 300 will be described.

FIG. 3B is a structural cross-sectional view of a film forming apparatus (epitaxial growth apparatus 1000) for forming an epitaxial film of silicon carbide on the substrate 1 by a chemical vapor deposition method. In the epitaxial growth apparatus 1000, the box-shaped heat insulating material 1200 forming the film forming chamber 1100, the raw material gas introduction port 1300 for introducing the raw material gas into the film forming chamber 1100, and the substrate 1 are mounted on the flat surface portion of the substrate mounting portion 301. A rotary stage 1400 for holding and rotating the placed susceptor 300 is provided, and the protrusion 304 of the substrate holder 300 is fitted into the recess 1401 provided at the upper end of the cylinder of the rotary stage 1400 to fit the susceptor 300. Is fixed to the rotary stage 1400.

The procedure for growing an epitaxial film on the substrate 1 using the epitaxial growth device 1000 will be described. For example, in the film formation chamber 1100 of the epitaxial growth device 1000, the substrate 1 is placed on the flat surface portion of the substrate mounting portion 301 in the susceptor 300. Will be done. Alternatively, the susceptor 300 on which the substrate 1 is placed is set in the film forming chamber 1100 of the epitaxial growth apparatus 1000. After that, the temperature in the film forming chamber 1100 is raised to a designated temperature. After the temperature rises, the susceptor 300 on which the substrate 1 is placed is rotated by the rotation stage 1400 as shown by the arrow A, and is introduced into the film forming chamber 1100 from the raw material gas introduction port 1300 in the direction indicated by the arrow B. A film can be formed by spraying the gas onto the substrate 1.

FIG. 4 is an explanatory diagram showing the flow of the raw material gas supplied from the upper side of the substrate 1 mounted on the susceptor 300. When the epitaxial film is grown on the substrate 1, the raw material gas is blown from the upper side of the substrate 1 onto the front surface 1a of the substrate 1. As a result, film formation proceeds due to the reaction on the front surface 1a of the substrate 1, but the raw material gas is affected by the centrifugal force due to the rotation of the substrate 1, and the entire front surface 1a of the substrate 1 is affected. Can be distributed to.

In the flow of the raw material gas from the center of the front surface 1a of the substrate 1 to the end 1b of the substrate 1, the raw material gas that reaches the end 1b of the substrate 1 by the action of the ring-shaped eaves 303 in the susceptor 300 is the susceptor 300. It reaches the wall portion 302a. The flow of the raw material gas is blocked by the wall portion 302a, so that convection occurs in the vicinity of the end portion 1b of the substrate 1, and this convection causes variations in the film thickness distribution of the epitaxial film in the front surface 1a of the substrate 1. It may contribute to the cause. Therefore, it is preferable that the front surface 1a of the substrate 1 and the upper surface 302b of the susceptor 300 are on the same plane without a step so as not to cause this convection, but the rotation of the susceptor 300 can prevent the substrate 1 from popping out. You also need to. Therefore, the length in the vertical direction between the flat surface portion 301a side end portion 303b and the flat surface portion 301a of the ring-shaped eaves portion 303 is set to be larger than the thickness of the substrate 1 as described above.

By setting in this way, it is possible to suppress abnormal film formation without obstructing the natural flow of the raw material gas sprayed on the substrate 1, and to prevent the film formation from being biased on the film formation target surface of the substrate 1. It is possible to suppress and maintain a stable film formation. Further, by preventing or suppressing the invasion of the raw material gas into the side surface of the mounted substrate 1 during the film forming process, the adhesion or accumulation of silicon carbide on the substrate mounting portion 301 or the wall portion 302a is prevented or suppressed. can do.

FIG. 9 shows a schematic cross-sectional view of a state in which the substrate 1 is placed on the susceptor 10 to which the silicon carbide 400 is attached by repeatedly performing the film forming process by the epitaxial growth apparatus 1000.

By repeating the film forming process, silicon carbide 400 adheres to and accumulates on the substrate mounting portion 11 and the wall portion of the susceptor 10, which is important for holding the substrate 1 and the substrate mounting portion 11 and the wall. The above-mentioned silicon carbide 400 causes protrusions and steps in the portion. When such protrusions or steps occur, even if the substrate 1 is mounted on the substrate mounting portion 11, the substrate 1 becomes unstable due to a gap between the substrate mounting portion 11 and the substrate 1 or the like. It will be placed. If the susceptor is rotated in the film forming chamber 1100 in this state, the susceptor 10 may not be able to firmly hold the substrate 1, and the substrate 1 may fly from the susceptor. In this case, the substrate 1 may be damaged due to a collision with the inner wall of the film forming chamber 1100 or the like. Further, since the film formation cannot be controlled on the flying substrate 1, a desired epitaxial film cannot be grown. And, as described above, since it takes a lot of cost and time to remove the silicon carbide 400 adhering to the susceptor 10, it is not preferable to increase the frequency of maintenance for removing the silicon carbide 400.

However, the above problem can be solved by using the above susceptors 100, 200, and 300.

That is, in the case of the susceptors 100, 200, and 300 having a ring-shaped eaves, the presence of the ring-shaped eaves allows the raw material gas to pass through the side surface of the substrate 1 to silicon carbide on the substrate mounting portion 301 and the wall portion 302a. It is possible to avoid the harmful effects of adhering. Therefore, even if the susceptor 300 is used repeatedly, the substrate 1 can be stably and firmly held, and the substrate 1 can be prevented from flying. Therefore, in all the substrates 1 installed in the epitaxial growth apparatus 1000. The yield can be increased by being able to form an epitaxial film.

Further, since silicon carbide does not easily adhere to the substrate mounting portion 301 and the wall portion 302a, the susceptor 300 can be used repeatedly with a longer life. In addition, the number of maintenances for removing the silicon carbide 400 is reduced, or maintenance is not required, so that the cost for film formation can be suppressed. Therefore, stable film formation by epitaxial growth of silicon carbide can be performed inexpensively and for a long period of time.

By the way, in the susceptor 300, as shown in FIG. 3A, a plurality of protrusions 304 are provided on the back surface side of the substrate mounting portion 301, and these protrusions 304 are shown in FIG. 3B. It has a structure fitted to a recess 1401 provided at the upper end of the cylinder of the rotary stage 1400. When such a structure is adopted, the susceptor 300 is firmly attached to the cylindrical upper end portion of the rotary stage 1400 as compared with the structure of FIG. 11 in which the protrusion 12c of the susceptor 20 is locked to the cylindrical inner wall surface of the rotary stage 1400. Since it is fixedly mounted, it has an advantage that the protrusion of the susceptor 300 and the protrusion of the substrate 1 from the susceptor 300 can be reliably prevented.

(2) Dimensions of the susceptor Dimension d1 (distance between the outer peripheral edge of the flat surface portion and the outer peripheral edge of the substrate 1 mounted in the center of the flat surface portion) and dimension d2 (ring-shaped eaves portion 103) of the susceptor 100 exemplified in FIG. Distance between the open end and the outer peripheral edge of the substrate 1 placed in the center of the flat surface), dimension d3 (thickness of the ring-shaped eaves 103), and dimension d4 (flat side of the ring-shaped eaves 103). The vertical distance between the upper surface of the substrate 1 placed on the end portion and the flat surface portion) will be described below.

(2-1) Dimension d1
As described above, the diameter of the outer periphery of the flat surface portion in the substrate mounting portion 101 is set to be equal to or larger than the outer diameter of the substrate 1, but the dimension d1 shown in FIG. It is preferable to set the distance) from 0.5 mm to 0.7 mm, that is, the difference between the diameter of the outer circumference of the flat surface portion and the outer diameter of the substrate 1 to 1.0 mm to 1.4 mm.

When set in this way, the ring-shaped eaves 103 reliably prevent the substrate 1 from popping out, so that there is an advantage that the lid material of the substrate holder according to Patent Document 2 can be omitted.

(2-2) Dimension d2
As described above, the opening diameter of the ring-shaped eaves 103 is set to be equal to or larger than the outer diameter of the substrate 1, but the dimension d2 shown in FIG. The distance between the outer peripheral edge of the substrate 1) is 0.2 mm to 0.3 mm, that is, the difference between the diameter of the opening in the ring-shaped eaves 103 and the outer diameter of the substrate 1 is 0.4 mm to 0.6 mm. It is preferable to set to.

When set in this way, the work of mounting and taking out the substrate 1 on the substrate mounting portion 101 of the susceptor 100 becomes easy, so that there is an advantage that the work efficiency is improved.

(2-3) Dimension d3 and Dimension d4
For the vertical dimension setting in the substrate 1 and the susceptor 100, the thickness of the ring-shaped eaves 103 is 0.5 mm or less, and between the flat end side end of the ring-shaped eaves 103 and the upper surface of the substrate 1 placed on the flat surface. It is preferable to set the vertical distance in the above to 0.3 mm or less.

When set in this way, abnormal film formation can be suppressed without obstructing the natural flow of the raw material gas sprayed on the substrate 1, so that the film formation target surface of the substrate 1 is stably suppressed from being biased. It has the advantage of being able to maintain a good film formation. Further, since the raw material gas can be prevented or suppressed from entering the side surface of the mounted substrate 1 during the film forming process, it is possible to prevent or suppress the adhesion or deposition of silicon carbide on the substrate mounting portion 101 or the wall portion. Has advantages.

(3) Although an example of using the susceptor in the silicon carbide epitaxial growth device 1000 has been mainly given, other uses can be considered as the susceptor according to the present invention. The susceptor according to the present invention is useful when the substrate is rotated for processing. For example, a film forming apparatus for rotating the substrate to form a polycrystalline film of silicon carbide, and a predetermined treatment liquid on the surface to be coated of the substrate. The susceptor can also be used for a spin coater for spin-coating a substrate, a substrate cleaning device having a mechanism for removing the cleaning liquid by rotating the substrate after cleaning the surface to be cleaned with the cleaning liquid, and the like.

3. 3. Substrate processing apparatus Next, an example of the substrate processing apparatus according to the present invention will be described.

The substrate processing apparatus according to the present invention includes the above-mentioned susceptor according to the present invention.

The substrate processing apparatus is not particularly limited as long as it includes a susceptor. For example, a film forming apparatus for forming a film on a substrate by a chemical vapor deposition method may be used. Specifically, the epitaxial growth apparatus 1000 shown in FIG. 3B as a film forming apparatus is made of silicon carbide. An epitaxial film can be formed on the substrate of.

Further, since the susceptor according to the present invention is useful when the substrate is rotated for processing, the substrate processing apparatus according to the present invention is a spin coater that spin-coats a predetermined treatment liquid on the surface to be coated with the substrate. There may be. As yet another embodiment, the substrate cleaning device may be provided with a mechanism for removing the cleaning liquid by rotating the substrate after cleaning the surface to be cleaned of the substrate with the cleaning liquid.

4. Substrate processing method Next, an example of the substrate processing method according to the present invention will be described.

The substrate processing method according to the present invention includes a substrate holding step of holding the substrate in the susceptor according to the present invention, and a processing step of processing the substrate while rotating the susceptor after the substrate holding step.

The processing step may be a film forming step of forming a film on the substrate.

As a substrate processing method according to the present invention, a substrate processing method for growing an epitaxial film on the substrate 1 using the epitaxial growth apparatus 1000 will be described as an example.

(1) Substrate holding step As a substrate holding step, for example, the substrate 1 is placed on the substrate mounting portion 301 of the susceptor 300 in the film forming chamber 1100 of the epitaxial growth apparatus 1000, or the outside of the film forming chamber 1100. In the present invention, there is a step of mounting the substrate 1 on the substrate mounting portion 301 of the susceptor 300. In this case, the susceptor 300 is set in the film forming chamber 1100 of the epitaxial growth apparatus 1000 after the substrate holding step.

(2) Treatment step As the treatment step, for example, in the case of the film formation step, the temperature in the film formation chamber 1100 shown in FIG. 3B is raised to a designated temperature after the substrate holding step. After the temperature rises, the susceptor 300 on which the substrate 1 is placed is rotated by the rotation stage 1400 as shown by the arrow A, and the raw material is introduced into the film forming chamber 1100 from the raw material gas introduction port 1300 in the direction indicated by the arrow B. By blowing the gas onto the substrate 1, the film forming process can be performed.

The treatment step is not limited to the film forming step, and for example, when a spin coater is used, it may be a step of spin-coating a predetermined treatment liquid on the surface to be coated of the substrate 1. As yet another aspect, when a substrate cleaning device is used, the step may be a step of cleaning the surface to be cleaned of the substrate 1 with the cleaning liquid and then rotating the substrate to remove the cleaning liquid.

(3) Other Steps The substrate processing method according to the present invention may include further steps in addition to the substrate holding step and the processing step. For example, a curing step for cleaning the substrate 1 to be treated, a determination step for determining whether or not the substrate has been sufficiently treated after the treatment step, and the like can be mentioned.

Hereinafter, examples of the present invention will be specifically described. However, the present invention is not limited to these examples.

[Details of evaluation]
When the substrate 1 is placed on the susceptor 300 [see FIG. 3 (a)] according to the present invention using the epitaxial growth apparatus 1000 shown in FIGS. 3 (b) and 8 and the epitaxial growth film is formed into a film. The presence or absence of protrusion of the substrate 1 and the influence on the film thickness of the epitaxial growth film were evaluated in the case where the substrate 1 was placed on the conventional susceptor 10 (see FIG. 8) and the epitaxial growth film was formed.

In the evaluation, the only difference is whether the susceptor 300 according to the present invention is used or the conventional susceptor 10 is used, and the substrate 1, the composition and mixing ratio of the raw material gas, the flow rate and spraying time of the raw material gas, and the substrate 1 The film formation was repeated under the same film formation conditions such as the rotation speed of the above.

<Evaluation of protrusion of substrate 1>
The film formation process on the substrate 1 was repeated by the epitaxial growth apparatus 1000, and the number of times the substrate 1 popped out per the cumulative film formation amount was evaluated.

As the substrate 1, a silicon carbide single crystal wafer having a diameter of 152.4 mm (6 inches) and a thickness of 0.5 mm was used.

The conventional susceptor 10 (see FIG. 8) is made of carbon and has a diameter of 163 mm, a diameter of the flat surface portion 11a of the substrate mounting portion 11 of 153 mm, a width of the peripheral portion 12 of 5 mm, a thickness of the substrate mounting portion 11 of 2 mm, and a wall. The height of the portion 12a was set to 0.5 mm according to the thickness of the substrate 1.

Further, the susceptor 300 [see FIG. 3A] according to the present invention is made of carbon and has a diameter of 163 mm, a flat surface portion 301a in the substrate mounting portion 301 having a diameter of 153 mm, a peripheral portion 302 having a width of 5 mm, and a substrate mounting portion. The thickness of 301 is 2 mm, the height of the wall portion 302a is 0.8 mm (thickness of substrate 1 0.5 mm + 0.3 mm of the above dimension d4), and the thickness of the ring-shaped eaves 303 is 0.5 mm (see the above dimension d3). ), The distance between the outer peripheral end of the flat surface portion 301a and the outer peripheral end of the substrate 1 placed in the center of the flat surface portion 301a is 0.6 mm (see the above dimension d1), and the open end portion of the ring-shaped eaves portion 303. The distance from the outer peripheral edge of the substrate 1 placed in the center of the flat surface portion 301a was set to 0.3 mm (see the above dimension d2).

Further, in the film forming process, the susceptor 300 and the conventional susceptor 10 according to the present invention were repeatedly used from the beginning until the end of the test without replacement.

The results are shown in FIG. In FIG. 6, the horizontal axis is the cumulative film formation amount of the epitaxial growth film formed, the white graph is the case where the susceptor 300 according to the present invention is used, and the black-painted graph is the case where the conventional susceptor 10 is used. be. Further, the item "100 μm" indicates the number of times the substrate 1 is popped out during the period from the first film forming process to the cumulative film forming amount of 100 μm. The item "300 μm" indicates the number of times the substrate 1 pops out while the cumulative film formation amount is from 100 μm to 300 μm. The same applies to the items of 500 μm to 1500 μm, and the film formation treatment was performed 10 times for each item.

From the results shown in FIG. 6, when the conventional susceptor 10 is used, the substrate 1 does not pop out up to the item where the cumulative film formation amount is 300 μm, but the cumulative film formation amount exceeds 500 μm and the substrate 1 suddenly appears. It was found that the frequency of pop-outs increased. After each film formation process, the state of the susceptor 10 from which the substrate 1 had popped out was confirmed. As a result, silicon carbide gradually adhered to the flat surface portion 11a surface and the wall portion 12a of the substrate mounting portion 11, and the cumulative film formation amount. When it exceeded 500 μm, it was confirmed that the adhered silicon carbide had grown into steps and protrusions, and it was clear that these steps and protrusions caused the substrate 1 to pop out.

On the other hand, when the susceptor 300 according to the present invention was used, the substrate 1 did not pop out even once from the start of the film forming process to the state where the cumulative film forming amount was 1500 μm. In particular, due to the presence of the ring-shaped eaves 303, silicon carbide hardly adhered to the substrate mounting portion 301 and the wall portion 302a of the susceptor 300. Further, even when silicon carbide adheres to the substrate mounting portion 301 or the wall portion 302a and a step or protrusion is generated at the final stage of the repeated film forming process, the presence of the ring-shaped eaves portion 303 causes the substrate 1 to be present. Was able to prevent the popping out.

<Evaluation of the effect of the lid material 20 on the substrate holder of Patent Document 2 on the film thickness>
Here, the susceptor 300 [see FIG. 3A] according to the present invention and the substrate holder (see FIG. 10) according to Patent Document 2 to which the lid material 20 is attached to the susceptor 10 are used, and the thickness is large. The lid materials 20 different from 0.5 mm to 2.0 mm were prepared, and the epitaxial growth film was formed once as each substrate holder, and the epitaxial growth film was formed on the substrate 1.

Then, the film thickness of the obtained epitaxial growth film was measured and compared with the average value of the film thickness of the epitaxial growth film when the susceptor 300 according to the present invention and the substrate holder according to Patent Document 2 were used, and the film thickness was biased. Was evaluated.

(1) When the substrate holder according to Patent Document 2 is used The results are shown in FIG. In the graph of FIG. 7, the thickness of the lid material 20 is taken as the horizontal axis, and the average value of the film thickness of the epitaxial growth film when the susceptor 10 (conventional susceptor 10) is used without using the lid material 20 for 0 mm is shown. Shown as 100%.

Then, when the average value of this film thickness is compared with the film thickness of the thickest portion of the epitaxial growth film formed by using the lid material 20, the case where the film thickness is 1.2 times thicker is obtained. The case where the film thickness was 120% and 1.4 times thick was plotted as 140%.

When the substrate holder according to Patent Document 2 is used, if the thickness of the lid material 20 is 1 mm or less, the thickness of the epitaxial growth film formed as shown in the graph of FIG. 7 is substantially uniform, and the lid material is substantially uniform. It was possible to obtain a film having the same film thickness as when 20 was not used. When the substrate holder according to Patent Document 2 is used, if the thickness of the lid material 20 is 1 mm or less, the lid material 20 does not obstruct the natural flow of the raw material gas, and it is almost the same as the state without the lid material 20. It points to that.

(2) When the susceptor 300 according to the present invention On the other hand, when the susceptor 300 according to the present invention is used, the raw material gas is not blocked by the ring-shaped eaves 303 from the flow of the raw material gas supplied from the upper side. Since it is easy to reach the outer peripheral portion of the substrate 1, it was confirmed that the thickness of the formed epitaxial growth film is almost uniform if the above-mentioned dimensions d1 to d4 are set.

According to the present invention, it is possible to prevent a decrease in work efficiency due to the lid material, suppress the film formation / deposition of silicon carbide on the susceptor, prevent the substrate from popping out from the susceptor, and to the outer peripheral portion of the substrate. Since the raw material gas can be evenly reached, it has industrial applicability as a susceptor capable of stably forming a film by epitaxial growth of silicon carbide at low cost and for a long period of time.

1 Board 1a Front surface 1b End 10 Suceptor 11 Board mounting part 11a Flat part 12 Peripheral part 12a Wall part 12b Top surface 12c Protrusion part 20 Lid material 20a Opening part 30 Fixing means 100 Sucepter 101 Board mounting part 101a Flat part 102 Peripheral part 102a Wall part 102b Top surface 103 Ring-shaped eaves part 103a Opening part 103b Flat part side end 200 Suceptor 201 Board mounting part 201a Flat part 202 Peripheral part 202a Wall part 202b Top surface 300 Suceptor 301 Board mounting part 301a Flat part 302 Peripheral part 302a Wall part 302b Top surface 303 Ring-shaped eaves 303a Opening part 303b Flat part side end part 304 Projection part 400 Silicon carbide 1000 Emetic growth device 1100 Formation chamber 1200 Insulation material 1300 Raw material gas introduction port 1400 Rotating stage 1401 Recessed d1 Flat surface Distance between the outer peripheral edge of the portion and the outer peripheral edge of the substrate placed in the center of the flat surface d2 Distance between the open end of the ring-shaped eaves and the outer peripheral edge of the substrate mounted in the center of the flat surface d3 Thickness of the ring-shaped eaves d4 Vertical distance between the flat surface side end of the ring-shaped eaves and the upper surface of the substrate mounted on the flat surface A Arrow B Arrow

Claims (10)

A substrate mounting portion on which the substrate to be processed is mounted on a flat surface portion and the diameter of the outer periphery of the flat surface portion is equal to or larger than the outer diameter of the substrate, and a substrate mounting portion surrounding the substrate mounting portion and perpendicular to the outer peripheral edge of the flat surface portion. In a susceptor having a peripheral edge portion composed of a wall portion extending in a direction and an upper surface extending horizontally from the upper end of the wall portion toward the outside of the flat surface portion.
A ring-shaped eaves portion is provided at the upper end of the wall portion of the peripheral edge portion so as to horizontally project from the upper surface of the peripheral edge portion toward the inside of the flat surface portion, and the diameter of the opening in the ring-shaped eaves portion is equal to or larger than the outer diameter of the substrate. The susceptor is characterized in that the length in the vertical direction between the flat portion side end portion of the ring-shaped eaves portion and the flat surface portion is larger than the thickness of the substrate. The susceptor according to claim 1, wherein the difference between the diameter of the outer periphery of the flat surface portion and the outer diameter of the substrate is 1.0 mm to 1.4 mm. The susceptor according to any one of claims 1 to 2, wherein the difference between the diameter of the opening in the ring-shaped eaves and the outer diameter of the substrate is 0.4 mm to 0.6 mm. The susceptor according to any one of claims 1 to 3, wherein the ring-shaped eaves have a thickness of 0.5 mm or less. Any one of claims 1 to 4, wherein the length in the vertical direction between the flat surface side end of the ring-shaped eaves and the upper surface of the substrate placed on the flat surface is 0.3 mm or less. The described susceptor. A substrate processing apparatus comprising the susceptor according to any one of claims 1 to 5. The substrate processing apparatus according to claim 6, further comprising a film forming apparatus for forming a film on the substrate by a chemical vapor deposition method. A cylindrical rotating stage on which a susceptor is placed is provided in the film forming chamber of the film forming apparatus, and a protrusion is provided on the back surface side of the substrate mounting portion of the susceptor according to any one of claims 1 to 5. The substrate processing apparatus according to claim 7, wherein the susceptor is fixed to the rotary stage by fitting the protrusion of the susceptor into the concave portion provided at the upper end of the cylindrical shape of the rotary stage. A substrate holding step of holding the substrate in the susceptor according to any one of claims 1 to 5.
After the substrate holding step, a processing step of processing the substrate while rotating the susceptor, and a processing step of processing the substrate.
A substrate processing method comprising. The substrate processing method according to claim 9, wherein the processing step is a film forming step of forming a film on the substrate.

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