A chip carrier disk

Abstract

A wafer carrier (10), wherein the bottom of a groove of the wafer carrier (10) is divided into a first area (S1) close to the center (C) of the wafer carrier and a second area (S2) far from the center (C) of the wafer carrier by a first dividing line (L1) passing through the center (O) of the groove, the bottom of the groove comprising a groove bottom surface and a protruding structure (210) formed on the groove bottom surface, the surface of the protruding structure (210) being a curved surface, the vertex (H) of the curved surface being located in the second area (S2) of the groove bottom, and the average height of the protruding structure located in the second area (S2) being higher than the average height of the protruding structure located in the first area. The design structure of the bottom of the groove of the wafer carrier (10) can better match the warping in the epitaxial process of the active area of ​​a III-V nitride wafer, so that the temperature field distribution is more uniform, thereby improving the wavelength uniformity of the light-emitting epitaxial wafer.

Description

Technical Field

[0001] The invention relates to semiconductor manufacturing equipment, in particular to a wafer carrier for MOCVD. Background Art

[0002] Graphite disk is a very important accessory in MOCVD equipment. Currently, the commonly used graphite disks are round with some grooves on them. These grooves are used to place the substrate and then grow the epitaxial layer on the substrate. The graphite disk is made of high-purity graphite and coated with SiC coating on the surface. During the epitaxial growth process, the graphite disk containing the substrate is radiated and heated by heating wire in the MOCVD reaction chamber.

[0003] Figure 1 FIG. 1 is a schematic diagram of an existing wafer carrier. The wafer carrier 10 includes three grooves 20 , in which a wafer 30 is placed. Figure 2 Shown Figure 1 The structural diagram at the A-A' section in the figure shows that the bottom of the groove is generally flat, convex, or concave. For GaN on silicon technology, stress engineering technology is required to grow the buffer layer. When growing the active area, the epitaxial wafer is convexly warped. Therefore, for the light-emitting structure of GaN on silicon, convex grooves are generally used. However, the following problems may occur when using the convex groove: when the chip 30 is placed in the groove 20, due to the high-speed rotation of the chip carrier 10 during the growth of the chip 30, the chip 30 in the groove 20 is affected by the centrifugal force and will move the chip 30 away from the center C of the chip carrier. The convex structure at the bottom of the groove will make the gap between the part of the chip 30 away from the center C of the chip carrier 10 and the bottom of the chip carrier 10 relatively large, that is, the distance difference between the chip 30 and the bottom of the groove 20 is large, resulting in obvious uneven heating during the growth of the chip 30, which affects the quality of the chip 30. In addition, the wavelength of the III-V nitride light-emitting chip 30 is more sensitive to temperature, which can easily cause large differences in wavelength within the chip 30, which will greatly increase the time and cost and reduce the yield of subsequent chip manufacturing and sorting work.

[0004] Based on the above, it is necessary to provide a wafer carrier structure for use in MOCVD equipment that can effectively improve the uniformity of wafer epitaxial heating. Summary of the invention

[0005] The purpose of the present invention is to provide a wafer carrier that adjusts the shape of the bottom of the groove to effectively improve the uniformity of wafer epitaxial heating, improve the quality and epitaxy of III-V nitride epitaxial growth, and the wavelength uniformity within the optoelectronic epitaxial wafer.

[0006] The present invention provides a wafer carrier, comprising at least one groove, wherein the groove comprises:

[0007] A groove bottom, wherein the groove bottom is divided into a first area close to the center of the wafer carrier and a second area far from the center of the wafer carrier by a first dividing line passing through the center of the groove, the groove bottom includes a groove bottom surface and a protruding structure formed on the groove bottom surface, the point at which the edge of the protruding structure is closest to the center of the wafer carrier is a first edge point, and the point at which the edge of the protruding structure is farthest from the center of the wafer carrier is a second edge point;

[0008] The average height of the protruding structures located in the second area is higher than the average height of the protruding structures located in the first area.

[0009] As an optional technical solution, the groove further includes a groove side portion, and the edge of the protruding structure is connected to the groove side portion.

[0010] As an optional technical solution, the first dividing line is a straight line, and the first dividing line is perpendicular to a first center line passing through the center of the wafer carrier plate and the center of the groove.

[0011] As an optional technical solution, the first dividing line is an arc with the center of the wafer carrier as the center and the distance from the center of the wafer carrier to the center of the groove as the radius.

[0012] As an optional technical solution, the surface of the protruding structure is a curved surface, the curved surface has a vertex, and the projection of the vertex on the horizontal plane is located in the second area of ​​the bottom of the groove.

[0013] As an optional technical solution, the projection of the vertex on the horizontal plane is located on a first center line, and the first center line passes through the center of the wafer carrier and the center of the groove.

[0014] As an optional technical solution, the curved surface of the protruding structure is composed of countless curves starting from the vertex to the edge of the protruding structure, and the curvature radius of each of the countless curves is a fixed value, wherein the curvature radius of the countless curves gradually decreases from the first edge point along the edge of the protruding structure to the second edge point.

[0015] As an optional technical solution, the curved surface of the protruding structure is composed of countless curves passing through the vertex and with both ends located at the edge of the protruding structure, one end of each of the curves close to the center of the chip carrier is a first end, and one end of each of the curves away from the center of the chip carrier is a second end, wherein the radius of curvature of each of the curves gradually decreases from the first end to the second end.

[0016] As an optional technical solution, the height of the edge of the protruding structure gradually increases from the first edge point along the edge of the protruding structure to the second edge point.

[0017] As an optional technical solution, on the curved surface of the protruding structure, the tangent slope of the curve from the second edge point to the vertex is a positive value, and the tangent slope of the curve from the vertex to the first edge point changes from zero to a negative value.

[0018] Compared with the prior art, the present invention has the following technical effects:

[0019] The bottom of the groove of the wafer carrier of the present invention is divided into a first area close to the center of the wafer carrier and a second area away from the center of the wafer carrier by a first dividing line passing through the center of the groove. The bottom of the groove includes a groove bottom surface and a protruding structure formed on the groove bottom surface. The surface of the protruding structure is a curved surface, and the vertex of the curved surface is located in the second area of ​​the bottom of the groove. Therefore, the average height of the protruding structure located in the second area is higher than the average height of the protruding structure located in the first area. The design structure of the bottom of the groove of the wafer carrier can better match the problem of a large gap between the wafer and the bottom of the groove caused by centrifugal force and the protruding structure of the III-V group nitride wafer, so that the wafer under the centrifugal force of the rotation of the wafer carrier always maintains a reasonable gap with the wafer carrier, reducing the influence of centrifugal force on the growth of the wafer, ensuring the stability of temperature and airflow, and making the temperature field distribution more uniform, thereby improving the quality of the epitaxial layer wafer, improving the wavelength uniformity of the light-emitting epitaxial wafer, and improving the yield, and has a wide application prospect in the field of semiconductor manufacturing equipment design and manufacturing.

[0020] In order to make the above and other purposes, features and advantages of the present application more obvious and understandable, preferred embodiments are specifically listed below and described in detail with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 Shown is a schematic diagram of a conventional wafer carrier;

[0022] Figure 2 Shown Figure 1 Schematic diagram of the structure at the A-A' section;

[0023] Figure 3 FIG. 1 is a schematic top view of a wafer carrier in an embodiment of the present application;

[0024] Figure 4a FIG. 1 is a schematic diagram showing the position of the first dividing line at the bottom of the groove in an embodiment of the present invention;

[0025] Figure 4b FIG. 1 is a schematic diagram showing the position of the first dividing line at the bottom of the groove according to another embodiment of the present invention;

[0026] Figure 5 Shown is a schematic structural diagram of a single groove in one embodiment of the present invention;

[0027] Figure 6 Shown is a schematic structural diagram of a single groove in another embodiment of the present invention;

[0028] Figure 7 Shown is a schematic structural diagram of a single groove in another embodiment of the present invention;

[0029] Figure 8 Shown is a schematic structural diagram of a single groove in yet another embodiment of the present invention;

[0030] To facilitate understanding of the present invention, all reference numerals appearing in the present invention are listed below:

[0031] Wafer carrier 10 Wafer carrier center C

[0032] Groove 20 Groove center O

[0033] First edge point O1 Second edge point O2

[0034] Protrusion structure 210 First region S1

[0035] Curves k1, k2, k3, k4 and k5 Second region S2

[0036] Curves O1O2, A1A2 and B1B2 First dividing line L1

[0037] Curvature radii r1, r2, r3, r4 and r5 First center line L2

[0038] Protruding structure vertex H DETAILED DESCRIPTION

[0039] The technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application.

[0040] Figure 3 FIG. 1 is a top view of a wafer carrier 10 in an embodiment of the present application. Figure 3 As shown, the wafer carrier 10 includes at least one groove 20. Figure 3The number of the grooves 20 is 3, which are arranged in order around the center C of the wafer carrier 10. However, the present application does not limit the number, size and distribution of the grooves 20 of the wafer carrier 10. Those skilled in the art should know that the number, size and arrangement of the grooves 20 can be flexibly set according to the size of the wafer 30. The bottom of the groove 20 is divided into a first area S1 close to the center C of the wafer carrier and a second area S2 far from the center C of the wafer carrier by the first dividing line L1. The bottom of the groove includes a groove bottom surface and a protruding structure 210 formed on the groove bottom surface, the point where the edge of the protruding structure 210 is closest to the center C of the wafer carrier is the first edge point, and the point where the edge of the protruding structure 210 is farthest from the center C of the wafer carrier is the second edge point. The average height of the protruding structure 210 located in the second area S2 is higher than the average height of the protruding structure 210 located in the first area S1.

[0041] Due to the centrifugal force of the rotation of the wafer carrier 10, the wafer 30 will be moved in the direction away from the center C of the wafer carrier, and the protruding structure at the bottom of the groove will make the gap between the portion of the wafer 30 away from the center C of the wafer carrier 10 and the bottom of the wafer carrier 10 relatively large, that is, resulting in a large difference in the distance between the wafer and the bottom of the groove 20. The present invention adjusts the height of the protruding structure 210 at the bottom of the groove to appropriately increase the height of the portion of the protruding structure away from the center C of the wafer carrier, so that the wafer 30 affected by the centrifugal force of the rotation of the wafer carrier always maintains a reasonable gap with the groove 20 of the wafer carrier 10, thereby reducing the influence of centrifugal force on wafer growth, ensuring the stability of temperature and airflow, and making the temperature field distribution more uniform, thereby improving the quality of the epitaxial layer wafer.

[0042] Figure 4a as well as Figure 4b FIG. 1 is a schematic diagram of the position of the first dividing line at the bottom of the groove 20 in an embodiment of the present invention. Figure 4a As shown, the first dividing line L1 is a straight line, and the first dividing line L1 is perpendicular to the first center line L2 passing through the center C of the wafer carrier and the center O of the groove. The first area S1 and the second area S2 are equal in area, wherein the first area S1 is close to the center C of the wafer carrier, and the second area S2 is far from the center C of the wafer carrier. In another embodiment, as shown in 4b, the first dividing line L1 is an arc with the center C of the wafer carrier as the center and the distance from the center C of the wafer carrier to the center O of the groove as the radius, and the arc-shaped first dividing line L1 divides the bottom of the groove into two parts with unequal areas, and the first area S1 and the second area S2 are unequal in area, wherein the first area S1 is close to the center C of the wafer carrier, and the second area S2 is far from the center C of the wafer carrier.

[0043] like Figure 3As shown, the edge of the protruding structure 210 is connected to the side of the groove 20, and the surface of the protruding structure 210 is a curved surface, and the curved surface has a vertex H. Figure 3 The curve around the vertex H in the groove 20 in the top view can be regarded as a contour line. Figure 3 The isoheight line position distribution shows that the average height of the protrusion structure 210 in the second area S2 is higher than the average height of the protrusion structure 210 in the first area S1. The projection of the vertex H on the horizontal plane is located on the first center line L2 of the second area S2 of the groove bottom.

[0044] Figure 5 FIG. 2 is a schematic diagram of the structure of a single groove 20 in an embodiment. Figure 5 As shown, the projection of the vertex H on the horizontal plane is located on the first center line L2 of the second area S2 of the bottom of the groove. The curved surface of the protruding structure 210 is composed of countless curves starting from the vertex H to the edge of the protruding structure 210, and the curvature radius of each of the countless curves is a fixed value, wherein the curvature radius of the countless curves gradually decreases from the first edge point along the edge of the protruding structure 210 to the second edge point. Figure 5 Five curves k1-k5 are shown in the figure. The curvature radii of the five curves k1-k5 are r1, r2, r3, r4 and r5, respectively. They gradually decrease from the first edge point O1 close to the center C of the wafer carrier along the edge of the protruding structure 210 to the second edge point O2, that is, r5<r4<r3<r2<r1.

[0045] Figure 6 FIG. 2 is a schematic diagram of the structure of a single groove 20 according to another embodiment of the present invention. In the previous embodiment, it is mentioned that the surface of the protruding structure 210 is composed of countless curves passing through the vertex H. In comparison, in this embodiment, the curved surface of the protruding structure 210 can also be regarded as composed of countless curves passing through the vertex H and having both ends located at the edge of the protruding structure 210. Figure 6 In the example, three curves O1O2, A1A2 and B1B2 passing through the vertex H are drawn, and the projections of the numerous curves passing through the vertex H on the horizontal plane are straight lines. The end of each of the curves close to the center C of the wafer carrier is the first end, and the end of each of the curves away from the center C of the wafer carrier is the second end, wherein the radius of curvature of each of the curves gradually decreases from the first end to the second end. Specifically, as Figure 6The points O1, A1 and B1 are the first ends of the curves O1O2, A1A2 and B1B2, and the points O2, A2 and B2 are the second ends of the curves O1O2, A1A2 and B1B2. For the curves O1O2, A1A2 and B1B2, the radius of curvature of each curve changes from the first end to the second end, and the radius of curvature gradually decreases from the first end to the second end.

[0046] Figure 7 FIG. 2 is a schematic diagram of a cross-sectional structure of a groove 20 in another embodiment of the present invention. Figure 7 As shown, the edge height of the protruding structure 210 gradually increases from the first edge point O1 along the edge of the protruding structure 210 to the second edge point O2.

[0047] Figure 8 A schematic diagram of the cross-sectional structure of the groove 20 in another embodiment of the present invention is shown in FIG. Figure 8 As shown, on the curved surface of the protruding structure 210, the tangent slope of the curve from the second edge point O2 to the vertex H is a positive value, and the tangent slope of the curve from the vertex H to the first edge point O1 changes from zero to a negative value, that is, there is an inflection point in the curve from the vertex H to the first edge point O1, so that the tangent slope of the curve before the inflection point decreases, and the tangent slope of the curve after the inflection point increases. Among them, the meaning of the positive value of the tangent slope of the curve is that the curve is peak-shaped, and the meaning of the negative curvature is that the curve is valley-shaped.

[0048] In the above-mentioned embodiment of the present invention, the height distribution of the protruding structure 210 at the bottom of the groove is adjusted by adjusting the position of the vertex H of the protruding structure 210 and the curvature radius of the curved surface in different areas, so that the height of the portion of the protruding structure away from the center C of the wafer carrier is appropriately increased, so that the wafer 30 affected by the centrifugal force of the rotation of the wafer carrier always maintains a reasonable gap with the groove 20 between the wafer carriers 10, thereby reducing the influence of the centrifugal force on the growth of the wafer.

[0049] In summary, the bottom of the groove of the wafer carrier of the present invention is divided into a first area close to the center of the wafer carrier and a second area away from the center of the wafer carrier by a first dividing line passing through the center of the groove. The bottom of the groove includes a bottom surface of the groove and a protruding structure formed on the bottom surface of the groove. The surface of the protruding structure is a curved surface, and the vertex of the curved surface is located in the second area of ​​the bottom of the groove. Therefore, the average height of the protruding structure located in the second area is higher than the average height of the protruding structure located in the first area. The design structure of the bottom of the groove of the wafer carrier can better match the warping of the III-V nitride wafer, so that the wafer under the centrifugal force of the rotation of the wafer carrier always maintains a reasonable gap with the wafer carrier, reduces the influence of the centrifugal force on the growth of the wafer, ensures the stability of temperature and airflow, and makes the temperature field distribution more uniform, thereby improving the quality of the epitaxial layer wafer, improving the wavelength uniformity of the light-emitting epitaxial wafer, and improving the yield. It has broad application prospects in the field of semiconductor manufacturing equipment design and manufacturing.

[0050] In the present application, the material of the wafer carrier may be graphite. However, the present application does not impose any particular limitation on the material of the wafer carrier, and those skilled in the art know that other materials may be selected according to design requirements.

[0051] The above description is only the preferred embodiment of the present application and is not intended to limit the present application. For those skilled in the art, the present application may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A wafer carrier, comprising at least one groove, characterized in that: The groove comprises: A groove bottom, wherein the groove bottom is divided into a first area close to the center of the wafer carrier and a second area far from the center of the wafer carrier by a first dividing line passing through the center of the groove, the groove bottom includes a groove bottom surface and a protruding structure formed on the groove bottom surface, the point at which the edge of the protruding structure is closest to the center of the wafer carrier is a first edge point, and the point at which the edge of the protruding structure is farthest from the center of the wafer carrier is a second edge point; The surface of the protruding structure is a curved surface having a vertex, the projection of the vertex on the horizontal plane is located in the second area at the bottom of the groove, and the average height of the protruding structure located in the second area is higher than the average height of the protruding structure located in the first area.

2. The wafer carrier according to claim 1, characterized in that: The groove further includes a groove side portion, and the edge of the protruding structure is connected to the groove side portion.

3. The wafer carrier according to claim 1, characterized in that: The first dividing line is a straight line, and the first dividing line is perpendicular to a first center line passing through the center of the wafer carrier and the center of the groove.

4. The wafer carrier according to claim 1, characterized in that: The first dividing line is an arc with the center of the wafer carrier as the center and the distance from the center of the wafer carrier to the center of the groove as the radius.

5. The wafer carrier according to claim 1, characterized in that: The projection of the vertex on the horizontal plane is located on a first center line, and the first center line passes through the center of the wafer carrier and the center of the groove.

6. The wafer carrier according to claim 5, characterized in that: The curved surface of the protruding structure is composed of countless curves starting from the vertex to the edge of the protruding structure, and the curvature radius of each of the countless curves is a fixed value, wherein the curvature radius of the countless curves gradually decreases from the first edge point along the edge of the protruding structure to the second edge point.

7. The wafer carrier according to claim 5, characterized in that: The curved surface of the protruding structure is composed of countless curves passing through the vertex and with both ends located at the edge of the protruding structure, wherein the end of each curve close to the center of the chip carrier is the first end, and the end of each curve away from the center of the chip carrier is the second end, wherein the radius of curvature of each curve gradually decreases from the first end to the second end.

8. The wafer carrier according to claim 5, characterized in that: The height of the edge of the protruding structure gradually increases from the first edge point along the edge of the protruding structure to the second edge point.

9. The wafer carrier according to claim 5, characterized in that: On the curved surface of the protruding structure, the tangent slope of the curve from the second edge point to the vertex is a positive value, and the tangent slope of the curve from the vertex to the first edge point changes from zero to a negative value.

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