JP6846303B2 - Grinding equipment and grinding method - Google Patents

Description

The present invention relates to a grinding apparatus and a grinding method used for grinding deposits deposited on the inner wall of a film forming chamber.

Silicon carbide (SiC), which is a semiconductor material, has a wider bandgap than Si (silicon), which is currently widely used as a device substrate. Therefore, a single crystal SiC substrate is used for power devices, high-frequency devices, and high temperature. Research is being conducted to manufacture operating devices and the like.

As a method for forming a single crystal film of silicon carbide, a chemical vapor deposition method (CVD method) is used to combine a C-containing gas (propane gas or the like) and a Si-containing gas (silane gas or the like). A method of growing a silicon carbide single crystal film by a chemical reaction and a method of growing a silicon carbide single crystal film using monomethylsilane as a raw material for a CVD method are known.

However, when the CVD method is used, silicon carbide also adheres to and accumulates on the inner wall of the reaction vessel. The silicon carbide fine particles (SiC deposits) deposited on the inner wall peel off and fall off, and fall and adhere to the growth surface of the silicon carbide thin film, which causes crystal growth to be inhibited or defects to occur. Therefore, it is necessary to periodically remove the SiC deposits deposited on the inner wall of the film forming chamber. Conventionally, when silicon carbide is deposited on the inner wall of the film forming chamber, the method of removing the SiC deposit is a method of scraping off with a tool during the stop period between the epitaxial growth steps, and the wall of the film forming chamber is regularly removed. The method of exchanging with is adopted.

Manual grinding of the deposited silicon carbide and replacement of the wall of the film forming chamber require an extremely long working time, and the film forming chamber is open to the atmosphere for a long period of time, resulting in a decrease in yield. There is concern that it will adversely affect productivity.

Therefore, as a method for removing the deposited silicon carbide deposits without opening the apparatus, there is a cleaning method for chemically removing the deposits, and a method using various etching gases has been proposed. (Patent Document 1). However, since the etching gas is highly reactive, there are problems such as damage to the members in the reaction vessel and residual gas components causing contamination.

JP-A-2014-154865

The present invention has been made in view of such circumstances, and removes the deposits deposited on the inner wall of the film forming chamber in a short time without using an etching gas and without opening the film forming chamber. It is an object of the present invention to provide a grinding device and a grinding method that enable the above.

In order to solve the above problems, the present invention employs the following means.

(1) The grinding apparatus according to one aspect of the present invention is a grinding member composed of a susceptor for a substrate to be deposited, which is arranged in a film forming chamber, a flat plate-shaped base portion, and a convex portion formed on the surface thereof. A transport means for transporting the grinding member so as to be mounted on the susceptor, and a rotating means for rotating the susceptor around a central axis, and one main surface of the base portion is the susceptor. When the susceptor and the grinding member are viewed in a plan view in a state where the grinding member is placed on the susceptor so as to face the grinding member, the outermost peripheral portion of the grinding member is outside the outermost peripheral portion of the susceptor. It is in.

(2) In the grinding apparatus according to (1), it is preferable that one or more convex portions are formed on the outer peripheral portion of at least one main surface of the base portion.

(3) In the grinding apparatus according to any one of (1) or (2), it is preferable that one or more of the convex portions are formed on the side surface of the base portion.

(4) In the grinding apparatus according to any one of (1) to (3), the convex portion is formed on a portion other than the outer peripheral portion on the other main surface of the base portion. Is preferable.

(5) In the grinding apparatus according to any one of (1) to (4), the convex portion formed on the outer peripheral portion of one main surface of the base portion and the other main surface of the base portion. It is preferable that at least one of the formed convex portion and the convex portion formed on the side surface of the base portion is arranged without a gap along the outer peripheral portion of the base portion.

(6) In the grinding apparatus according to any one of (1) to (5), a driving means for driving the susceptor or the side wall of the film forming chamber in a direction parallel to the central axis of the susceptor is provided. It is preferable to have more.

(7) In the grinding apparatus according to any one of (1) to (6), it is preferable that the grinding member has a structure extending parallel to the main surface of the base portion.

(8) The grinding method according to one aspect of the present invention is the grinding method using the grinding device according to any one of (1) to (7) above, and is before the film forming process on the substrate is performed. Alternatively, later, using the transport means, the step of mounting the grinding member on the susceptor, and using the rotating means, the susceptor or the side wall of the film forming chamber is rotated around the central axis of the susceptor. It has a process of making it.

(9) In the grinding method according to (8) above, the grinding method further includes a step of driving the susceptor or the side wall of the film forming chamber in a direction parallel to the central axis of the susceptor by using a driving means. It is preferable to have.

According to the grinding device and the grinding method of the present invention, by rotating the grinding member together with the susceptor, the convex portion formed on the outer peripheral portion of the grinding member is made to collide with the deposit deposited on the inner wall of the film forming chamber, and the convex portion is formed. This deposit can be ground by utilizing the rotational force generated in the part. Therefore, it is not necessary to manually grind the sediment and replace the wall of the film forming chamber, which requires an extremely long working time, and as a result, it is not necessary to open the film forming chamber to the atmosphere for a long period of time. It is possible to avoid the occurrence of productivity problems such as a decrease in yield.

It is a vertical sectional view of the film forming apparatus provided with the grinding apparatus which concerns on one Embodiment of this invention. It is a top view and a side view which show the structural example of the grinding member which the grinding apparatus of FIG. 1 has (a)-(f). (A) to (d) are a top view and a side view showing another configuration example of a grinding member included in the grinding apparatus of FIG. 1. It is a side view of the grinding member which the grinding apparatus of FIG. 1 has.

Hereinafter, the present invention will be described in detail with reference to the drawings as appropriate. In the drawings used in the following description, in order to make the features of the present invention easy to understand, the featured portions may be enlarged for convenience, and the dimensional ratios of each component may differ from the actual ones. There is. Further, the materials, dimensions, etc. exemplified in the following description are examples, and the present invention is not limited thereto, and can be appropriately modified and carried out within the range in which the effects of the present invention are exhibited. ..

[Structure of grinding equipment]
FIG. 1 is a vertical cross-sectional view of the film forming apparatus 10 provided with the grinding apparatus 100 according to the embodiment of the present invention, and is a deposit (depot) D of silicon carbide or the like generated by the film forming process or the like. However, it shows a state of being deposited on the inner wall 11a of the film forming chamber 11. The grinding apparatus 100 rotates the susceptor 101 for the substrate to be deposited, the grinding member 102, the conveying means 103 for transporting the grinding member 102, and the susceptor 101 around the central axis 101c arranged in the film forming chamber 11. It has a rotating means 104 to be made to rotate.

In the present invention, the susceptor means a member that supports a substrate when forming a film. The susceptor of the present invention may be a member that directly contacts and supports the substrate, or may be a member that supports the member that directly contacts the substrate, such as when the substrate is placed on a pedestal and transported.

The grinding member 102 may have a strength that does not damage at least when it comes into contact with a deposit (SiC deposit or the like) D deposited on the inner wall of the film forming chamber 11. The deposit D is mainly composed of silicon carbide, but it is formed by precipitating and solidifying fine polycrystals, and has a property of being fragile to mechanical impact. Silicon carbide itself is a substance with high hardness, but even if it has a hardness lower than that, it can be used as long as it is strong enough not to be damaged by mechanical impact on the deposition of the CVD method having the above-mentioned properties. is there. In addition, it is desirable to have high purity so that even if it is partially worn, it does not become a source of pollution. Examples of such a material include TaC-coated carbon, SiC-coated carbon, NbC-coated carbon, WC-coated carbon, TaC, SiC, NbC, WC, other metal carbides, diamond, SiO _{2, and the} like.

The grinding member 102 is composed of a flat plate-shaped (preferably disk-shaped) base portion (base material) 102A and a convex portion (projection portion) 102B formed on the surface thereof. The area of the main surface of the base 102A is larger than the area of the substrate mounting surface 101a of the susceptor 101. The size of the convex portion 102B is not particularly limited, but it is assumed that the tip portion thereof extends at least to a position in contact with the deposit D.

The convex portion 102B may have a shape that protrudes vertically with respect to the surface of the base portion 102A, a shape that protrudes diagonally, or a shape that has a bent portion and a curved portion. .. Further, the convex portion 102B may have either a shape having a constant cross-sectional area in the longitudinal direction (prism, cylinder, etc.) or a shape in which the cross-sectional area increases or decreases (pyramid, cone, truncated cone, truncated cone, etc.). ..

In the state where the grinding device 100 is operated, that is, when the grinding member 102 is rotated together with the susceptor 101, the grinding member 102 is placed on the susceptor 101 so that one main surface of the base 102A faces the susceptor 101. Placed. When the susceptor 101 and the grinding member 102 are viewed in a plan view in this state, the outermost peripheral portion of the grinding member 102 is outside the outermost peripheral portion of the susceptor. That is, in the same plan view, the grinding member 102 is larger than the susceptor 101.

Further, it is preferable that the grinding member 102 has a structure that is parallel to the main surface of the base portion 102A and radially spreads in a direction away from the center of rotation so that the radius of gyration becomes large in the operating state. With such a structure, for example, the radius of gyration is reduced during transportation of the grinding member 102 so as not to abut (contact) with the deposit D, and the radius of gyration is increased during rotation to form the deposit D. It can be in a state of contact. In this case, since the sediment D is not ground during transportation, it is possible to prevent the ground sediment D from reattaching to the transport arm. Examples of the structure for radially expanding the grinding member 102 include a structure utilizing the property that the rotating convex portion 102B expands in the direction away from the center of rotation due to inertia.

The method of transporting the grinding member 102 by the transporting means 103 is not particularly limited, but as shown in FIG. 1, for example, while supporting the central portion of the main surface of the base portion 102A from below by the transporting arm 103A. , A method in which the arm 103A is bent, expanded / contracted, rotated, or the like can be mentioned. When this method is used, for example, as shown in FIG. 1, it is preferable that a recess 101A through which the arm 103A passes is formed on the surface of the susceptor 101 (the surface on which the grinding member 102 is placed).

The film forming chamber 11 is provided with a carry-in entrance (not shown) for carrying the substrate or the pedestal on which the substrate is placed into the growth space in the film forming space. A substrate transfer mechanism (not shown) for transporting the substrate or the pedestal on which the substrate is placed onto the susceptor 101 is provided. The substrate transfer mechanism and the carry-in inlet may be used as a transfer means for the grinding member. Further, the transfer means 103 may be provided separately from the transfer mechanism of the substrate.

When supporting the base 102A during transportation of the grinding member 102 by sandwiching the outer peripheral portion of the base 102A from both sides in the thickness direction, it is not necessary to provide the recess 101A, so that the grinding member 102 has a wider surface. The grinding member 102 can be more strongly fixed to the susceptor 101.

The rotation method of the susceptor 101 and the grinding member 102 by the rotating means 104 is also not particularly limited, but for example, as shown in FIG. 1, a rod-shaped member 104A attached to the lower side of the central portion of the susceptor 101 is used. A method of rotating around the central axis 101c can be mentioned.

The film forming apparatus 10 is provided with a mechanism for rotating the substrate or the susceptor 101 in order to rotate the pedestal on which the substrate is placed. This susceptor rotation mechanism may be used as the rotation means 104. Further, another rotating mechanism may be used as the rotating means 104 by providing another concentric rotating shaft.

In order to transmit the rotational force of the susceptor 101 to the grinding member 102 without waste, it is preferable that the grinding member 102 is strongly fixed to the susceptor 101. Therefore, it is preferable that the grinding member 102 has a weight that does not slip at the contact portion, or the contact portion with the susceptor 101 has a rough surface. Alternatively, there is also a method in which a concavo-convex structure is provided at the opposite positions of the grinding member 102 and the susceptor 101 to fit (fit) each other. Further, as a fixing method, the base portion 102A of the grinding member may be attracted to the susceptor 101 by using an electrostatic chuck.

It is preferable that the grinding apparatus 100 further has a driving means (not shown) for driving the side wall of the susceptor 101 or the film forming chamber 11 in a direction substantially parallel to the central axis 101c of the susceptor (approximately vertical direction). .. In this case, the rotated convex portion 102B can be brought into contact (collision) with the deposit D deposited on the ceiling portion 11b and the floor portion 11c of the film forming chamber, and the entire inner wall of the film forming chamber 11 can be brought into contact with (collision). , It becomes possible to grind the deposit D.

The film forming apparatus 10 is provided with a susceptor elevating mechanism that raises and lowers the substrate or the pedestal on which the substrate is placed for transportation. This susceptor elevating mechanism may be used as the driving means. Further, in order to change the movable range, another elevating mechanism may be provided as the driving means.

The convex portion 102B is a portion that comes into contact with the deposit D in the rotational operation state of the grinding member 102. It is preferable that one or more convex portions 102B are formed on the outer peripheral portion of at least one main surface of the base portion 102A. In FIG. 1, the convex portion 102B projects from the outer peripheral portions of both main surfaces of the base portion 102A, but the configuration of the convex portion 102B is not limited to this example. A configuration example of the convex portion 102B is shown in FIGS.

2 (a) to 2 (f) show a shape (upper side) in which one main surface side of the grinding member 102 is viewed in a plan view, and a cross-sectional shape (lower side) passing through the convex portion 102B of the grinding member 102, respectively. It is a figure. Here, one main surface of the grinding member 102 may be either a main surface on the side (one side) facing the susceptor 101 or a main surface on the opposite side (the other side).

The convex portion 102B is formed on one or both of the main surface of the base 102A facing the susceptor 101 and the main surface on the opposite side, as shown in FIG. 2A, at only one outer peripheral portion. Alternatively, it may be formed at a plurality of locations as shown in FIG. 2 (b). When formed at a plurality of locations, the convex portions 102B are arranged at equal intervals along the outer circumference of the base portion 102A from the viewpoint of evenly distributing the mass of the convex portions 102B and maintaining the rotation surface (rotation direction) of the grinding member 102. It is preferable to be.

Further, the convex portion 102B may have a shape with a sharp tip (pyramid, cone, etc.) as shown in FIG. 2C, or a shape that becomes thinner as it approaches the tip (pyramid, truncated cone, etc.). Etc.).

When the convex portions 102B are formed at a plurality of positions, they may be arranged without gaps to form a continuous wall (ring) as shown in FIG. 2 (d). The shape of the wall is not particularly limited, but for example, it may have a uniform thickness, or the thickness may change in the height direction.

When the grinding device 100 has the driving means described above, the convex portion 102B has a main surface (the other main surface) on the side of the base 102A that does not face the susceptor 101, as shown in FIG. 2 (e). In the above, it is preferable that the film is formed not only on the outer peripheral portion but also on a portion other than the outer peripheral portion (central portion, intermediate portion). In this case, by driving the grinding member 102 or the side wall of the film forming chamber 11 to a position where the convex portion 102B abuts on the deposit D deposited on the ceiling portion 11b, the deposit D of the ceiling portion 11b is further driven. It is possible to grind in a wide range. Further, since the deposit D ground from the ceiling portion 11b will fall on the base portion 102A, it can be collected while being placed on the base portion 102A by using the transport means 103.

Further, when the grinding device 100 has the same driving means, the convex portion 102B has an outer peripheral portion and a portion (central portion) in contact with the susceptor 101 on the main surface of the base portion 102A on the side facing the susceptor 101. It is preferable that it is also formed in the removed portion (intermediate portion). In this case, by driving the grinding member 102 or the side wall of the film forming chamber 11 to a position where the convex portion 102B abuts on the deposit D deposited on the floor portion 11c, the deposit D deposited on the floor portion 11c. Can be ground in a wider range.

In order to evenly grind the deposit D of the ceiling portion 11b and the floor portion 11c, it is formed on each main surface of the base portion 102A from the viewpoint of evenly contacting the convex portion 102B with the deposited deposit D. The convex portions 102B to be formed are preferably randomly distributed as shown in FIG. 2 (f). From the same viewpoint, for example, if the convex portions 102B are distributed so as to form a screw, the convex portions 102B will surely come into contact with all the deposits D of the ceiling portion 11b and the floor portion 11c. , More preferred.

Further, it is preferable that one or more convex portions 102B are formed on the side surface of the base portion 102A, and for example, as shown in FIG. 3A, the convex portions 102B may be formed only at one position on the side surface of the base portion 102A. , As shown in FIG. 3 (b), it may be formed at a plurality of places. When the convex portions 102B are formed at a plurality of locations on the side surface, it is preferable that the convex portions 102B are arranged at equal intervals along the outer circumference of the base portion 102A from the same viewpoint as in the case of FIG. 2B. Further, as shown in FIG. 3C, the convex portion 102B may have a sharp tip. When the convex portions 102B are formed at a plurality of locations on the side surface, they may be arranged without gaps to form a continuous wall shape (annular ring) as shown in FIG. 3 (d).

FIG. 4 is a cross-sectional view when the grinding member 102 is cut in the thickness direction of the base portion 102A, and shows an example in which the above-described configurations are combined. As shown in FIG. 4, the convex portion 102B may be formed on both the main surface and the side surface of the base _{portion 102A except for the portion 102A 1 that abuts on the susceptor 101.}

The convex portion 102B may be branched in a plurality of directions. FIG. 4 shows an example _{in which the convex portion 102B 1} formed on the outer peripheral portion of the base portion 102A is branched. When the convex portion 102B ₁ is branched, the grinding effect of the deposit D can be enhanced by increasing the portion that comes into contact with the deposit portion D.

[How to grind deposits]
Each step of the method of grinding the deposit D using the grinding device 100 according to the present embodiment will be described.

(First step)
First, the grinding member 102 is placed on the susceptor 101 by using the transport means 103 in a state where the film formation process on the substrate has not been performed (before and after the film formation process, etc.), and a fitting method of an uneven structure or the like is performed. The grinding member 102 is fixed using.

(Second step)
Next, the rotating means 104 is used to rotate the side wall of the susceptor 101 or the film forming chamber 11 around the central axis 101c of the susceptor. The rotation speed at this time is preferably such that a rotational force required for removing the deposit D is generated, specifically, about 5 to 1000 rpm. It is preferable that the rotation speed is gradually increased from low speed. At this time, it is preferable to control the rotation speed while monitoring the load of the rotation drive motor. In addition, rotation in the opposite direction can be combined as appropriate.

(Third step)
Further, when the grinding device 100 is provided with a driving means, the side wall of the susceptor 101 or the film forming chamber 11 is driven along a direction substantially parallel to the central axis 101c of the susceptor.

By going through the first step and the second step, or the first step to the third step, the deposit D deposited on the inner wall surface 11a of the film forming chamber can be ground.

As described above, according to the grinding apparatus 100 and the grinding method according to the present embodiment, by rotating the grinding member 102 together with the susceptor 101, the convex portion 102B formed on the outer peripheral portion of the grinding member 102 is formed in the film forming chamber. The deposit D can be ground by colliding with the deposit D deposited on the inner wall of 11 and utilizing the rotational force generated in the convex portion 102B. Therefore, it is not necessary to manually grind the deposit D and replace the wall of the film forming chamber 11 which requires an extremely long working time, and as a result, it is necessary to open the film forming chamber 11 to the atmosphere for a long period of time. Therefore, it is possible to avoid the occurrence of productivity problems such as a decrease in yield.

The present invention can be widely used as an effective means for cleaning a film forming apparatus required in any film forming process.

10 ... Film formation device 11 ... Film formation chamber 11a ... Inner wall 11b of the film formation chamber ... Ceiling portion 11c ... Floor portion 100 ... Grinding device 101 ... Suceptor 101c ... Central axis 102 of the susceptor ... Grinding member 102A ... Base 102A ₁ ... Part 102B in contact with the susceptor 102B ... Convex portion 102B ₁ ... Convex portion 103 formed on the outer peripheral portion ... 103A ... Arm 104 ... Rotating means 104A ... Rod-shaped member D ... Sediment

Claims (12)

A susceptor for the substrate to be filmed, which is arranged in the film forming chamber,
A grinding member composed of a flat plate-shaped base and a convex portion formed on the surface thereof,
A transport means for transporting the grinding member so as to be mounted on the susceptor, and
It has a rotating means for rotating the susceptor around a central axis.
In a state where the grinding member is placed on the susceptor so that one main surface of the base faces the susceptor.
When viewed from the susceptor and the grinding member, the outermost peripheral portion of the grinding member, Ri outside near the outermost portion of the susceptor,
One or more convex portions are formed on the outer peripheral portion of at least one main surface of the base portion.
One or more convex portions are formed on the side surface of the base portion.
The convex portion is formed on a portion other than the outer peripheral portion on the other main surface of the base portion.
At least one of a convex portion formed on the outer peripheral portion of one main surface of the base portion, a convex portion formed on the other main surface of the base portion, and a convex portion formed on the side surface of the base portion is provided. Sort without gaps along the outer periphery of the base, grinding apparatus characterized that you have been continuous annular wall formation. The grinding apparatus according to claim 1, further comprising a driving means for driving the susceptor or the side wall of the film forming chamber in a direction parallel to the central axis of the susceptor. The grinding member, the grinding apparatus of any crab according to claim 1 or 2, characterized in that it has a structure extending in parallel with the main surface of the base. A susceptor for the substrate to be filmed, which is arranged in the film forming chamber,
A grinding member composed of a flat plate-shaped base and a convex portion formed on the surface thereof,
A transport means for transporting the grinding member so as to be mounted on the susceptor, and
It has a rotating means for rotating the susceptor around a central axis.
In a state where the grinding member is placed on the susceptor so that one main surface of the base faces the susceptor.
When the susceptor and the grinding member are viewed in a plan view, the outermost peripheral portion of the grinding member is outside the outermost peripheral portion of the susceptor.
A grinding apparatus characterized in that the grinding member has a structure that is parallel to the main surface of the base portion and radially spreads in a direction away from the center of rotation so that the radius of gyration becomes large in an operating state. The grinding apparatus according to claim 4 , wherein one or more convex portions are formed on the outer peripheral portion of at least one main surface of the base portion. The convex portion is, the grinding apparatus according to claim 4 or 5, characterized in that it is formed one or more sides of the base. The grinding apparatus according to any one of claims 4 to 6 , wherein the convex portion is formed on a portion other than the outer peripheral portion on the other main surface of the base portion. At least one of a convex portion formed on the outer peripheral portion of one main surface of the base portion, a convex portion formed on the other main surface of the base portion, and a convex portion formed on the side surface of the base portion is provided. The grinding apparatus according to any one of claims 4 to 7 , wherein the grinding apparatus is arranged without a gap along the outer peripheral portion of the base portion. The aspect according to any one of claims 4 to 8 , further comprising a driving means for driving the susceptor or the side wall of the film forming chamber in a direction parallel to the central axis of the susceptor. Grinding device. A plurality of the convex portions are formed on a portion other than the outer peripheral portion on the other main surface of the base portion, and in a state of rotating together with the grinding member, in the entire region facing the portion other than the outer peripheral portion. The grinding apparatus according to any one of claims 1 to 9, wherein any one of the plurality of convex portions is distributed so as to overlap with each other. A grinding method using the grinding apparatus according to any one of claims 1 to 10.
The step of placing the grinding member on the susceptor using the conveying means, and
A grinding method comprising the step of rotating the susceptor or the side wall of the film forming chamber around the central axis of the susceptor by using the rotating means. The grinding method according to claim 11 , further comprising a step of driving the susceptor or the side wall of the film forming chamber in a direction parallel to the central axis of the susceptor by using a driving means. ..

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