JP2011165697A - Vapor phase epitaxy device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a vapor phase epitaxy device capable of inhibiting heat transfer from a wafer to a storage part when the wafer moves and comes into contact with the storage part of a wafer holder. <P>SOLUTION: In the vapor phase epitaxy device 1, the storage part 21 formed on a surface side of the wafer holder 7 for holding the wafer 5 is a recess dented in a thickness direction of the wafer holder 7, comprises a bottom 25 and a side face 27 extending in a thickness direction from an outer periphery of the bottom 25, and has a protrusion 23 provided on the side face 27. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a vapor phase growth apparatus. More particularly, the present invention relates to a vapor phase growth apparatus having a wafer holder that reduces thermal shrinkage of a wafer.

  Conventionally, a silicon wafer or the like is heat-treated at a high temperature in a compound production line or is processed in a gas atmosphere, and a thin film such as GaN is uniformly grown on the surface of the silicon wafer or the like (for example, patents). Reference 1). In these processes, a wafer holder formed of a material having high thermal conductivity and holding a silicon wafer is used.

JP 2004-55595 A

  However, in Patent Document 1, in the process of rotating or transporting the wafer holder, the wafer moves and the outer peripheral surface of the wafer contacts the side surface of the pocket (accommodating portion) of the wafer holder, and heat is transferred from the contact portion to the wafer holder. As a result of the movement, a phenomenon called so-called thermal shrinkage occurs in which the temperature of the contact portion of the wafer decreases. Due to the heat sink, the wafer has uneven heating, and the film thickness distribution of the thin film formed on the surface of the wafer is not uniform, which may lead to a decrease in wafer yield.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a vapor phase growth apparatus that can suppress heat transfer from a wafer to a housing portion when the wafer comes into contact with a side surface of the housing portion of the wafer holder.

  In order to solve the above-described problems, the present invention has the following features.

  A first feature of the present invention is a vapor phase growth apparatus (vapor phase growth apparatus 1) that includes a wafer holder (wafer holder 7) that holds a wafer (wafer 5) and heats the wafer to form a growth film on the wafer. The wafer holder is formed with an accommodating portion (accommodating portion 21) for accommodating the wafer, and the accommodating portion extends from the bottom surface (bottom surface 25) and the outer peripheral edge of the bottom surface in the thickness direction of the wafer holder. The side surface includes a side surface (side surface 27), and three or more projections (projections 23) are provided on the side surface, and the three or more projections are moved when the wafer moves toward the side surface of the housing portion. The gist is that the protrusion is arranged at a position where the wafer can come into contact with at least one of the above.

  Accordingly, even when the wafer holder is transported or rotated to move the wafer toward the side surface of the accommodating portion, the contact area can be minimized because the wafer hits the protrusion. For this reason, heat transfer from the wafer to the wafer holder can be suppressed to prevent heat shrinkage, so that the thickness of the growth film formed on the surface of the wafer becomes uniform and the yield of the wafer is improved. When the number of the protrusions is one, the outer peripheral surface of the wafer comes into contact with the side surface when the wafer moves toward the side surface on which the protrusion is not provided. When there are two protrusions, the outer peripheral surface of the wafer may come into contact with the side surface between the two protrusions. Accordingly, at least three or more protrusions are provided, and are arranged at a position where the wafer can come into contact with at least one of the protrusions when the wafer 5 moves toward the side surface of the housing portion.

  The gist of the second feature of the present invention is that the tip (tip 31) of the projection (projection 23) is formed in an arc shape.

  The third feature of the present invention is summarized in that the tip portion (tip portion 31) of the projection (projection 23) has a radius of curvature of 0.5 mm or more in plan view.

  In the fourth feature of the present invention, the circumferential end portion (circumferential end portion 33) of the projection connecting the projection (projection 23) and the side surface (side surface 27) of the accommodating portion (accommodating portion 21) is: The gist is that it is formed in an arc shape and the radius of curvature of the circumferential end is 10 mm or more in plan view.

  In the fifth feature of the present invention, the tip (tip 31) of the projection (projection 23) is formed to have the same protruding length from the side surface in the thickness direction of the wafer holder. It is a summary.

  The sixth feature of the present invention is summarized in that the protrusion (protrusion 23) is arranged point-symmetrically with respect to the center of the accommodating portion (accommodating portion 21).

  The gist of the seventh feature of the present invention is that the distance between adjacent projections of the projections (projections 23) is substantially constant.

  The eighth feature of the present invention is summarized in that the wafer holder (wafer holder 7) is made of silicon carbide.

  According to the vapor phase growth apparatus according to the present invention, when the wafer moves and contacts the side surface of the housing part of the wafer holder, heat transfer from the wafer to the housing part can be suppressed.

1 is a schematic cross-sectional view of a vapor phase growth apparatus according to an embodiment of the present invention. It is a perspective view of a wafer holder concerning an embodiment of the present invention. It is the top view to which the accommodating part of FIG. 2 was expanded. It is sectional drawing by the AA line of FIG. It is a perspective view which shows the protrusion of the accommodating part by embodiment of this invention. FIG. 6 is a plan view of FIG. 5.

  Hereinafter, details of a vapor phase growth apparatus according to an embodiment of the present invention will be described with reference to the drawings. Specifically, (1) the overall configuration of the vapor phase growth apparatus, (2) the detailed configuration of the wafer holder, (3) the detailed configuration of the protrusion, (4) the operational effects, and (5) other embodiments will be described.

  However, it should be noted that the drawings are schematic, and the thicknesses and ratios of the material layers are different from actual ones. Therefore, specific thicknesses and dimensions should be determined in consideration of the following description. Moreover, the part from which the relationship and ratio of a mutual dimension differ also in between drawings is contained.

(1) Overall Configuration of Vapor Deposition Apparatus 1 First, the overall configuration of the vapor deposition apparatus 1 according to the present embodiment will be described with reference to FIG.

   FIG. 1 is a schematic cross-sectional view of a vapor phase growth apparatus 1 according to an embodiment of the present invention.

   The vapor phase growth apparatus 1 is disposed on the upper side of the growth chamber 3, a growth chamber 3 that can be sealed, a wafer holder 7 that is disposed inside the growth chamber 3 and has a housing portion (pocket) that holds the wafer 5, and A gas supply means 11 for supplying a mixed gas 9 of a source gas and a carrier gas toward the wafer 5, a heating means 13 for heating the wafer 5, a wafer holder support 15 on which the wafer holder 7 is placed, the wafer holder 7 and Rotating means 17 for rotating the wafer holder support 15 and exhaust means 19 disposed below the growth chamber 3 and exhausting an exhaust gas 18 containing a source gas and a carrier gas are provided.

   Since the wafer holder 7 is mounted on the wafer holder support 15, the wafer holder 7 can be rotated together with the wafer holder support 15 by operating the rotating means 17. When the mixed gas 9 is supplied to the inside of the growth chamber 3 by the gas supply means 11 while rotating the wafer holder 7 and heating the wafer 5 via the wafer holder 7 by the heating means 13 as described above, A thin film grows.

(2) Detailed Configuration of Wafer Holder 7 Next, the detailed configuration of the wafer holder 7 will be described with reference to FIG.
FIG. 2 is a perspective view of the wafer holder 7 according to the embodiment of the present invention.

   The wafer holder 7 is formed in a substantially disk shape in plan view, and a plurality of accommodating portions (pockets) 21 are provided on the surface side thereof. The accommodating portion 21 is formed in a recess that is recessed in the thickness direction of the wafer holder 7, and the wafer 5 is accommodated in the accommodating portion 21. The wafer holder 7 is preferably formed of a material having high thermal conductivity such as silicon carbide.

(3) Detailed structure of protrusion Next, the detailed structure of the protrusion 23 provided in the accommodating part 21 of the wafer holder 7 is demonstrated using FIGS.

  3 is an enlarged plan view of the accommodating portion 21 of FIG. 2, FIG. 4 is a cross-sectional view taken along line AA of FIG. 3, and FIG. 5 is a perspective view showing the protrusion 23 of the accommodating portion 21 according to the embodiment of the present invention. 6 is a plan view of FIG.

  As shown in FIGS. 3 and 4, each accommodating portion 21 is formed in a substantially circular shape in plan view, and is formed in a concave portion that is recessed in the thickness direction of the wafer holder 7. Specifically, the accommodating portion 21 includes a bottom surface 25 having a substantially circular shape in plan view and a side surface 27 extending from the outer peripheral edge of the bottom surface 25 to the surface side. The bottom surface 25 is below the upper surface 29 (on the wafer holder 7). It is formed so as to be recessed in the thickness direction).

  Further, as shown in FIG. 3, the protrusions 23 are arranged at five locations along the circumferential direction of the side surface 27 of the housing portion 21. It is necessary to provide three or more protrusions 23 in total, and it is preferable that the protrusions 23 be arranged symmetrically with respect to the center of the housing portion 21 in plan view. When there is one protrusion 23, the outer peripheral surface of the wafer 5 comes into contact with the side surface 27 when the wafer 5 moves toward the side surface 27 on the side where the protrusion 23 is not provided. When there are two protrusions 23, the outer peripheral surface of the wafer 5 may come into contact with the side surface 27 between the two protrusions 23 and 23. Accordingly, at least three protrusions 23 are provided, and the protrusions 23 are disposed at positions where the wafer 5 can come into contact with at least one of the protrusions 23 when the wafer 5 moves toward the side surface 27 of the housing portion 21. For example, when the diameter of the wafer 5 is 50 mm, the protrusions 23 are preferably arranged at 6 or more locations, when the diameter is 100 mm, the projections 23 are arranged at 5 locations or more, and when the diameter is 200 mm, the projections 23 are preferably arranged at 3 locations or more.

  Moreover, it is preferable that the space | interval (distance) along the circumferential direction of the side surface 27 between the adjacent protrusions 23 is substantially constant. Here, “substantially constant” means that all the intervals between adjacent protrusions 23 are measured, and the difference between the maximum value and the minimum value of these intervals is 3% with respect to the total length along the circumferential direction of the side surface 27. It means the following.

  Further, as shown in FIG. 4, the tip end portion 31 of the protrusion 23 has the same protruding length from the side surface 27 in the thickness direction of the wafer holder 7. That is, the tip end portion 31 of the protrusion 23 has the same protruding length that protrudes radially inward from the side surface 27 from the lower end to the upper end in the height direction of the side surface 27 of the housing portion 21. The protrusion 23 protrudes from the side surface 27 of the housing portion 21 toward the center of the housing portion 21, but the end edge of the tip portion 31 extends at right angles to the bottom surface 25 of the housing portion 21 in a side view. .

  FIG. 5 is a perspective view showing the protrusion 23 of the accommodating portion 21 according to the embodiment of the present invention, and FIG. 6 is a plan view of FIG.

  The front end portion 31 of the protrusion 23 is formed in an arc shape that protrudes toward the inside of the housing portion 21 in a plan view. The curvature radius of the front end portion 31 is set to R1, and the curvature radius R1 is preferably 0.5 mm or more.

  On the other hand, the protrusion 23 and the side surface 27 of the housing portion 21 are connected via a circumferential end 33 of the protrusion 23. The circumferential end 33 is formed in an arc shape that is recessed outward in the diameter in plan view. The curvature radius of the circumferential end 33 is set to R2, and the curvature radius R2 is preferably 10 mm or more.

(4) Operational Effects The operational effects according to the present invention will be described below.

  The vapor phase growth apparatus 1 according to this embodiment includes a wafer holder 7 that holds a wafer 5, and is a vapor phase growth apparatus 1 that heats the wafer 5 to form a growth film on the wafer 5. An accommodating portion 31 for accommodating the wafer 5 is formed. The accommodating portion 31 includes a bottom surface 25 and a side surface 27 extending from the outer peripheral edge of the bottom surface 25 in the thickness direction of the wafer holder 7. The protrusion 23 is arranged at a position where the wafer 5 can come into contact with at least one of the three or more protrusions 23 when the wafer 5 moves toward the side surface 27 of the accommodating portion 31. Yes.

  Accordingly, even when the wafer holder 7 is transported or rotated to move the wafer 5 toward the side surface 27 of the housing portion 21, the contact area can be minimized because the wafer 5 hits the protrusion 23. For this reason, heat transfer from the wafer 5 to the wafer holder 7 can be suppressed to prevent heat shrinkage, the film thickness formed on the wafer 5 becomes uniform, and the yield of the wafer 5 is improved.

  Since the tip portion 31 of the projection 23 is formed in an arc shape, it is possible to suppress the impact force received from the tip portion 31 of the projection 23 when the wafer 5 comes into contact with the tip portion 31 of the projection 23. That is, if the tip 31 of the protrusion 23 is sharpened, the wafer 5 may be chipped or cracked by an impact at the time of contact.

  Since the distal end portion 31 of the projection 23 has a curvature radius in a preferable range of 0.5 mm or more in plan view, when the wafer 5 comes into contact with the distal end portion 31 of the projection 23, the distal end portion 31 of the projection 23. The impact force received from can be further suppressed.

  Since the circumferential end 33 of the projection 23 that connects the projection 23 and the side surface 27 of the housing portion 31 is formed in an arc shape, and the radius of curvature R2 of the circumferential end 33 is 10 mm or more in plan view, The rigidity of the protrusion 23 can be increased.

  The tip portion 31 of the protrusion 23 is formed to have the same protruding length from the side surface 27 in the thickness direction of the wafer holder 7. For this reason, even when the thickness of the wafer 5 is different, the outer peripheral surface of the wafer 5 comes into reliable contact with the tip 31 of the protrusion 23 when the wafer 5 moves.

  Since the protrusions 23 are arranged point-symmetrically with respect to the center of the accommodating portion 31, the protrusions 23 come into contact with the protrusions 23 even if the wafer 5 moves in any direction.

  Of the protrusions 23, the distance between the adjacent protrusions 23 and 23 is substantially constant, so that the wafer 5 can reliably contact the protrusions 23 in any direction.

  Wafer holder 7 is made of silicon carbide. Since this silicon carbide has a high thermal conductivity, a thin film can be uniformly and quickly formed on the surface of the wafer 5.

(5) Other Embodiments It should not be understood that the description and drawings that constitute part of the disclosure of the above-described embodiments limit the present invention. From this disclosure, various alternative embodiments, examples and operational techniques will be apparent to those skilled in the art.

  In the wafer holder 7 according to the present embodiment, five protrusions 23 are arranged at substantially equal intervals along the circumferential direction of the accommodating portion 21. However, the present invention is not limited to this, and six or more protrusions 23 may be arranged.

  As described above, the present invention naturally includes various embodiments that are not described herein. Therefore, the technical scope of the present invention is defined only by the invention specifying matters according to the scope of claims reasonable from the above description.

DESCRIPTION OF SYMBOLS 1 Vapor growth apparatus 5 Wafer 7 Wafer holder 21 Holding part 23 Protrusion 25 Bottom face 27 Side face 31 Tip part 33 Circumferential edge part

Claims (8)

A vapor phase growth apparatus comprising a wafer holder for holding a wafer and heating the wafer to form a growth film on the wafer,
The wafer holder is formed with an accommodating portion for accommodating the wafer,
The accommodating portion includes a bottom surface and a side surface extending in the thickness direction of the wafer holder from an outer peripheral edge of the bottom surface,
Three or more protrusions are provided on the side surface,
Vapor phase growth characterized in that, when the wafer moves toward the side surface of the housing portion, the protrusion is disposed at a position where the wafer can come into contact with at least one of the three or more protrusions. apparatus.   The vapor phase growth apparatus according to claim 1, wherein a tip portion of the protrusion is formed in an arc shape.   The vapor phase growth apparatus according to claim 2, wherein the tip of the protrusion has a radius of curvature of 0.5 mm or more in plan view.   A circumferential end portion of the projection connecting the projection and the side surface of the housing portion is formed in an arc shape, and a radius of curvature of the circumferential end portion is 10 mm or more in plan view. The vapor phase growth apparatus according to any one of claims 1 to 3.   5. The gas phase according to claim 1, wherein the tip of the protrusion has the same protruding length from the side surface in the thickness direction of the wafer holder. Growth equipment.   The vapor phase growth apparatus according to claim 1, wherein the protrusions are arranged point-symmetrically with respect to the center of the accommodating portion.   7. The vapor phase growth apparatus according to claim 1, wherein a distance between adjacent ones of the protrusions is substantially constant.   The vapor phase growth apparatus according to claim 1, wherein the wafer holder is made of silicon carbide.

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