Wafer carrier for epitaxial growth and method of using the same

Abstract

The present invention discloses a wafer carrier for epitaxial growth and a method for using the same, comprising a carrier body, a ring part and a support part, wherein the carrier body comprises a first part and a second part, wherein the diameter of the first part is smaller than the diameter of the second part; the ring part comprises a circular bottom and a step part arranged above the bottom, wherein the bottom penetrates the outer wall of the first part, and a side of the bottom facing the step part is flush with the top of the first part for carrying the wafer, and a suspended part is formed between the other side of the bottom facing away from the step part and the top of the second part; the support part is embedded in the suspended part to reduce the temperature of the ring part during the wafer epitaxy process. The present invention has the following advantages: the part between the carrier body and the ring part uses gas or thermal resistance material to increase thermal resistance and reduce heat conduction capacity so as to reduce the overall temperature of the ring part during the growth process, thereby increasing the thickness and composition uniformity of the epitaxial layer, reducing particle defects on the wafer and thus increasing the production yield of the epitaxial wafer.

Description

Technical Field

[0001] The present invention relates to the field of semiconductor manufacturing technology, and in particular to a wafer carrier for epitaxial growth and a method of using the same. Background Art

[0002] The description in this section merely provides background information related to the present disclosure and does not constitute prior art.

[0003] The wafer carrier used in the existing epitaxial reaction chamber is as follows Figure 1 As shown. In epitaxial growth equipment, graphite wafer carriers are necessary. They conduct heat and carry semiconductor wafers (substrates) in the epitaxial growth process, and maintain the uniformity of semiconductor deposition through rotation during the growth process. At present, the graphite wafer carriers provided by mainstream epitaxial equipment manufacturers are basically the same in structure. They all use a shallow groove designed on the graphite plate base according to the size and shape of the wafer to load the wafer. This design is relatively simple and reasonable in terms of manufacturing and maintenance. In order to reduce the risk of the wafer being thrown out by the rotating graphite wafer carrier, the depth of the wafer groove is deliberately designed to be deeper than the thickness of the wafer, so that the top of the wafer is lower than the height of the wafer carrier. This design leads to several problems in the demand for growing high-uniform epitaxial wafers: 1. Since the edge of the wafer is at the height of the wafer carrier, the height difference of this step causes gas turbulence in the wafer edge area, which easily increases the reaction time of the wafer edge area, resulting in poor thickness and composition uniformity in the epitaxial wafer edge area; 2. Because the wafer carrier is heated by the epitaxial growth equipment heating system, heat is transferred to various areas of the graphite wafer carrier including the edge of the carrier. The semiconductor deposits deposited on the wafer carrier ring provide energy for the decomposition of the semiconductor deposits due to the high temperature environment, and then the decomposed materials are brought to the edge of the wafer, resulting in poor thickness and composition uniformity in the edge area.

[0004] It should be noted that the above introduction to the technical background is only for the purpose of providing a clear and complete description of the technical solutions of the present invention and facilitating the understanding of those skilled in the art. It cannot be considered that the above technical solutions are well known to those skilled in the art simply because they are described in the background technology section of the present invention. Summary of the invention

[0005] The technical problem to be solved by the present invention is to provide a wafer carrier for epitaxial growth and a method of using the same in response to the deficiencies in the prior art. The height of the step portion in the ring is made to match the thickness of the wafer used, thereby eliminating the problem of epitaxial non-uniformity and by-product particles caused by growth gas turbulence due to the height difference between the wafer and the carrier; the thermal resistance is increased and the heat conduction capacity is reduced to reduce the overall temperature of the ring during the growth process, thereby improving the thickness and composition uniformity of the epitaxial product.

[0006] The embodiment of the present application discloses a wafer carrier for epitaxial growth, comprising:

[0007] A carrier plate body, the carrier plate body comprising a first portion and a second portion, the diameter of the first portion is smaller than the diameter of the second portion, and the first portion and the second portion form a step-shaped structure;

[0008] A ring portion, the ring portion comprising a circular bottom and a step portion arranged above the bottom, the bottom penetrating the outer wall of the first portion, and a side of the bottom facing the step portion is flush with the top of the first portion for carrying a wafer, and a suspended portion is formed between the other side of the bottom away from the step portion and the top of the second portion;

[0009] A support portion is embedded in the suspended portion to reduce the temperature of the ring portion during the epitaxial growth of the wafer.

[0010] Furthermore, the materials used to make the wafer carrier plate for epitaxial growth, the carrier plate body and the ring portion include but are not limited to graphite, graphite-coated silicon carbide and silicon carbide.

[0011] Furthermore, in the above-mentioned wafer carrier for epitaxial growth, the height of the step portion is consistent with the thickness of the wafer.

[0012] Furthermore, in the above-mentioned wafer carrier for epitaxial growth, the supporting portion includes a plurality of supporting seats, and the plurality of supporting seats are arranged in a circular array in the suspended portion with the first portion as the center.

[0013] Furthermore, in the above-mentioned wafer carrier plate for epitaxial growth, a distance is provided between the support seat and the outer wall of the first part and the outer wall of the second part in the axial direction, and the manufacturing materials of the carrier plate body, the ring part and the support part include but are not limited to graphite, graphite-coated silicon carbide and silicon carbide.

[0014] Furthermore, in the above-mentioned wafer carrier plate for epitaxial growth, one end face of the support seat is kept in contact with the outer wall of the first part, and the other end face is on the same axial plane with the outer wall of the second part. The materials for making the carrier plate body and the ring part include but are not limited to graphite, graphite-coated silicon carbide and silicon carbide, and the materials for making the support part include but are not limited to graphite, graphite-coated silicon carbide, silicon carbide, quartz, sapphire or other thermal resistance materials.

[0015] Furthermore, in the above-mentioned wafer carrier plate for epitaxial growth, the supporting part is an annular supporting seat, the inner wall of the supporting seat is in contact with the outer wall of the first part, and the outer wall of the supporting seat is spaced apart from the outer wall of the second part in the axial direction, and the suspended part uses gas as thermal resistance material.

[0016] Furthermore, in the above-mentioned wafer carrier plate for epitaxial growth, the supporting part is an annular supporting seat, the inner wall of the supporting seat is in contact with the outer wall of the first part, and the outer wall of the supporting seat is on the same axial plane as the outer wall of the second part, and the supporting seat is made of thermal resistance material.

[0017] The embodiment of the present application also discloses a method for using the wafer carrier for epitaxial growth, comprising the following steps:

[0018] Providing the above-mentioned wafer carrier for epitaxial growth;

[0019] Use a vacuum pen to suck the wafer and place it into the wafer carrier, or use a robotic arm to place the wafer and the ring part onto the support part;

[0020] Sending the wafer carrier carrying the wafer into an epitaxial furnace for growth;

[0021] After the epitaxial growth is completed, the wafer is adsorbed by a vacuum pen, or the wafer is taken out by a robotic arm.

[0022] In summary, the above structure adopted in the embodiment of the present invention has the following advantages:

[0023] 1. The wafer carrier for epitaxial growth described in the present invention has support parts of different shapes made around the ring part of the carrier body. The material can be but not limited to graphite, graphite-coated silicon carbide, silicon carbide, etc., so that the ring part does not completely contact the top of the carrier body. The thermal resistance material between the carrier body and the ring part can be but not limited to gas, quartz, sapphire, etc., which has high thermal resistance. Increasing the thermal resistance reduces the heat conduction capacity and thus reduces the overall temperature of the ring part during the growth process, improves the thickness and composition uniformity of the epitaxial product, and also reduces the particle defects on the wafer, thereby increasing the production yield of the epitaxial wafer;

[0024] 2. The wafer carrier for epitaxial growth described in the present invention has a step portion in the ring portion whose height is adapted to the thickness of the wafer (substrate) used, thereby eliminating the problem of epitaxial non-uniformity and by-product particles caused by growth gas turbulence due to the height difference between the wafer and the carrier.

[0025] To further understand the features and technical contents of the present invention, please refer to the following detailed description and drawings of the present invention. However, the drawings provided are only for reference and description and are not intended to limit the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the embodiments of this specification or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in this specification. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0027] Figure 1 It is a structural schematic diagram of an existing wafer carrier in the background technology of this application;

[0028] Figure 2 is a top view of a wafer carrier for epitaxial growth in an embodiment of the present application;

[0029] Figure 3 yes Figure 2 A cross-sectional schematic diagram of

[0030] Figure 4 and Figure 5 It is a schematic diagram of the structure between the wafer carrier plate and the support seat in the first embodiment of the present application;

[0031] Figure 6 and Figure 7 It is a schematic diagram of the structure between the wafer carrier and the support base in the second embodiment of the present application;

[0032] Figure 8 and Fig. 9 It is a schematic diagram of the structure between the wafer carrier plate and the support seat in the third embodiment of the present application;

[0033] Fig.10 and Fig.11 It is a schematic diagram of the structure between the wafer carrier plate and the support base in the fourth embodiment of the present application.

[0034] The figure markings of the above drawings are: 1. wafer carrier; 2. wafer; 3. carrier body; 31. first part; 32. second part; 4. ring part; 41. bottom; 42. step part; 5. suspended part; 6. supporting part. DETAILED DESCRIPTION

[0035] In order to enable those skilled in the art to better understand the technical solutions in this specification, the technical solutions in the embodiments of this specification will be clearly and completely described below in conjunction with the drawings in the embodiments of this specification. Obviously, the described embodiments are only part of the embodiments of this specification, not all of the embodiments. Based on the embodiments in this specification, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of this specification.

[0036] The following is an explanation of the embodiments of the present invention through specific embodiments. Those skilled in the art can understand the advantages and effects of the present invention from the contents disclosed in this specification. The present invention can be implemented or applied through other different specific embodiments, and the details in this specification can also be modified and changed in various ways based on different viewpoints and applications without departing from the concept of the present invention. In addition, the drawings of the present invention are only simple schematic illustrations and are not depicted according to actual sizes. It is stated in advance. The following embodiments will further explain the relevant technical contents of the present invention in detail, but the disclosed contents are not intended to limit the scope of protection of the present invention.

[0037] It should be understood that, although the terms "first", "second", "third", etc. may be used herein to describe various components or signals, these components or signals should not be limited by these terms. These terms are mainly used to distinguish one component from another component, or one signal from another signal. In addition, the term "or" used herein may include any one or more combinations of the associated listed items depending on the actual situation.

[0038] Reference Figures 1 to 11 As shown, the embodiment of the present application discloses a wafer carrier for epitaxial growth, comprising:

[0039] The carrier plate body 3 includes a first portion 31 and a second portion 32, wherein the diameter of the first portion 31 is smaller than the diameter of the second portion 32, and the first portion 31 and the second portion 32 form a step-shaped structure;

[0040] The ring portion 4 includes a circular bottom 41 and a step portion 42 arranged above the bottom 41, the bottom 41 penetrates the outer wall of the first portion 31, and one side of the bottom 41 facing the step portion 42 is flush with the top of the first portion 31 for carrying the wafer 2, and a suspended portion 5 is formed between the other side of the bottom 41 away from the step portion 42 and the top of the second portion 32;

[0041] The supporting portion 6 is embedded in the suspended portion 5 to reduce the temperature of the ring portion 4 during the epitaxial growth of the wafer 2 .

[0042] Specifically, in this embodiment, the materials used to make the carrier plate body 3 and the ring portion 4 include, but are not limited to, graphite, graphite-coated silicon carbide, and silicon carbide.

[0043] Specifically, in this embodiment, the height of the step portion 42 is consistent with the thickness of the wafer 2. In the process of manufacturing the ring portion 4, the height of the step portion 42 matches the thickness of the semiconductor wafer 2 (substrate) used by the user, the mainstream eight-inch silicon substrate is 1150μm, and the six-inch silicon substrate is 1000μm, which can reduce the thickness and composition uniformity problems caused by the gas turbulence between the height difference between the edge of the wafer 2 and the step portion 42, reduce the particle problems caused by the turbulence, and thus improve the production yield of the epitaxial wafer 2 due to the thickness, composition uniformity and particle defects.

[0044] Epitaxial growth refers to growing a single crystal layer with certain requirements and the same crystal orientation as the substrate on a single crystal substrate, just like the original crystal is extended outward for a certain period of time. The new single crystal layer grown epitaxially can be different from the substrate in terms of conductivity type, resistivity, etc., and multi-layer single crystals of different thicknesses and requirements can also be grown, thereby greatly improving the flexibility of device design and the performance of the device.

[0045] With the above structure, the wafer carrier 1 includes a carrier body 3, a ring 4 and a support 6. The ring 4 carries the circular edge of the wafer (substrate), and the manufacturing material can be but not limited to graphite, graphite-coated silicon carbide and silicon carbide. The height of the step portion of the ring 4 is adapted to the thickness of the wafer 2 (substrate). The carrier body 3 mainly carries the ring 4 and the wafer 2 and has the effect of conducting heat energy. The manufacturing material can be but not limited to graphite, graphite-coated silicon carbide and silicon carbide. In order to make a thermal resistance material between the ring 4 and the carrier body 3 to create a low-temperature ring effect, the support 6 of different shapes is made in the surrounding area of ​​the carrier body 3 carrying the ring 4. The manufacturing material can be but not limited to graphite, graphite-coated silicon carbide, silicon carbide, etc. The purpose is to prevent the ring 4 from being completely in contact with the top of the carrier body 3. The thermal resistance material between the carrier body 3 and the ring 4 can be but not limited to gas, quartz, sapphire, etc. High thermal resistance materials, increase thermal resistance, reduce heat conduction capacity, and thus reduce the overall temperature of the ring 4 during the growth process.

[0046] The height of the step portion 42 in the ring portion 4 is made to adapt to the thickness of the wafer 2 (substrate) used, thereby eliminating the problem of epitaxial non-uniformity and by-product particles caused by the turbulence of the growth gas due to the height difference between the wafer 2 and the carrier plate. By utilizing the design of the support portion 6, the local temperature of the ring portion 4 is reduced during the epitaxial growth process of the wafer 2, which can avoid the problem of uneven edge area of ​​the wafer 2 caused by the decomposition of the semiconductor material originally deposited on the ring portion 4 after excessive temperature; improve the thickness and composition uniformity of the epitaxial product, and also reduce the particle defects on the wafer 2, thereby increasing the production yield of the epitaxial wafer.

[0047] The embodiment of the present application also discloses a method for using the wafer carrier 1 for epitaxial growth, comprising the following steps:

[0048] Providing the above-mentioned wafer carrier 1 for epitaxial growth;

[0049] Use a vacuum pen to suck the wafer 2 and place it into the wafer carrier 1, or use a robot arm to place the wafer 2 and the ring 4 onto the support 6;

[0050] The wafer carrier 1 carrying the wafer 2 is sent into an epitaxial furnace for growth;

[0051] After the epitaxial growth is completed, the wafer 2 is sucked by a vacuum pen, or the wafer 2 is taken out by a robot arm.

[0052] The present invention is described in detail below through other specific embodiments:

[0053] Embodiment 1

[0054] Reference Figure 4 and Figure 5 In this embodiment, the support portion 6 includes a plurality of support seats, and the plurality of support seats are arranged in a circular array in the suspended portion 5 with the first portion 31 as the center.

[0055] Specifically, in this embodiment, a distance is provided between the support seat and the outer wall of the first part 31 and the outer wall of the second part 32 in the axial direction, and the manufacturing materials of the supporting plate body 3, the ring part 4 and the supporting part 6 include but are not limited to graphite, graphite-coated silicon carbide and silicon carbide.

[0056] Embodiment 2

[0057] Reference Figure 6 and Figure 7 In the present embodiment, one end face of the support seat is in contact with the outer wall of the first part 31, and the other end face is on the same axial plane with the outer wall of the second part 32. The materials for making the carrier plate body 3 and the ring part 4 include but are not limited to graphite, graphite-coated silicon carbide and silicon carbide. The materials for making the support part 6 include but are not limited to graphite, graphite-coated silicon carbide, silicon carbide, quartz, sapphire or other thermal resistance materials.

[0058] Embodiment 3

[0059] Reference Figure 8 and Fig. 9 In this embodiment, the support portion 6 is an annular support seat, the inner wall of the support seat is in contact with the outer wall of the first part 31, and the outer wall of the support seat is spaced apart from the outer wall of the second part 32 in the axial direction. The suspended portion 5 uses gas as a thermal resistance material, and the ring portion 4 only contacts the heat source of the annular support seat for conduction. The suspended portion 5 uses gas as a thermal resistance material to reduce the temperature of the ring portion during epitaxial growth.

[0060] Embodiment 4

[0061] Reference Fig.10 and Fig.11 In the present embodiment, the support portion 6 is an annular support seat, the inner wall of the support seat is in contact with the outer wall of the first portion 31, and the outer wall of the support seat is on the same axial plane as the outer wall of the second portion 32. The support seat is made of thermal resistance material, and the carrier plate body has a graphic support seat to support the ring portion 4. The ring portion 4 only contacts the heat source of the graphic support seat. The support seat made of thermal resistance material conducts a relatively low heat source to the ring portion, thereby reducing the temperature of the ring portion during the epitaxial growth process.

[0062] The contents disclosed above are only preferred feasible embodiments of the present invention, and are not intended to limit the scope of the present invention. Therefore, all equivalent technical changes made using the contents of the present invention's specification and drawings are included in the scope of the present invention.

[0063] The various embodiments in this specification are described in a progressive manner, and the same or similar parts between the various embodiments can be referred to each other, and each embodiment focuses on the differences from other embodiments. The present application can be used in many general or special computer system environments or configurations. For example: personal computers, server computers, handheld devices or portable devices, tablet devices, multi-processor systems, microprocessor-based systems, set-top boxes, programmable electronic devices, network PCs, minicomputers, mainframe computers, distributed computing environments including any of the above systems or devices, etc.

[0064] Although the present application has been described through embodiments, those skilled in the art will appreciate that there are many modifications and changes to the present application without departing from the spirit of the present application. It is intended that the attached embodiments include these modifications and changes without departing from the present application.

Claims

1. A wafer carrier for epitaxial growth, characterized in that: include: A carrier plate body, the carrier plate body comprising a first portion and a second portion, the diameter of the first portion is smaller than the diameter of the second portion, and the first portion and the second portion form a step-shaped structure; A ring portion, the ring portion comprising a circular bottom and a step portion arranged above the bottom, the bottom penetrating the outer wall of the first portion, and a side of the bottom facing the step portion is flush with the top of the first portion for carrying a wafer, and a suspended portion is formed between the other side of the bottom away from the step portion and the top of the second portion; A support portion is embedded in the suspended portion to reduce the temperature of the ring portion during the epitaxial growth of the wafer.

2. The wafer carrier for epitaxial growth according to claim 1, characterized in that: The materials used to make the carrier plate body and the ring include, but are not limited to, graphite, graphite-coated silicon carbide, and silicon carbide.

3. The wafer carrier for epitaxial growth according to claim 1, characterized in that: The height of the step portion is consistent with the thickness of the wafer.

4. The wafer carrier for epitaxial growth according to claim 1, characterized in that: The support portion includes a plurality of support seats, and the plurality of support seats are arranged in a circular array in the suspended portion with the first portion as the center.

5. The wafer carrier for epitaxial growth according to claim 4, characterized in that: The support seat is spaced apart from the outer wall of the first part and the outer wall of the second part in the axial direction. The materials used to make the carrier plate body, the ring part and the support part include but are not limited to graphite, graphite-coated silicon carbide and silicon carbide.

6. The wafer carrier for epitaxial growth according to claim 4, characterized in that: One end face of the support seat is in contact with the outer wall of the first part, and the other end face is on the same axial plane as the outer wall of the second part. The materials for making the carrier plate body and the ring part include but are not limited to graphite, graphite-coated silicon carbide and silicon carbide, and the materials for making the support part include but are not limited to graphite, graphite-coated silicon carbide, silicon carbide, quartz, sapphire or other thermal resistance materials.

7. The wafer carrier for epitaxial growth according to claim 1, characterized in that: The support portion is an annular support seat, the inner wall of the support seat is in close contact with the outer wall of the first portion, and the outer wall of the support seat is spaced apart from the outer wall of the second portion in the axial direction, and the suspended portion uses gas as a thermal resistance material.

8. The wafer carrier for epitaxial growth according to claim 1, characterized in that: The support portion is an annular support seat, the inner wall of the support seat is in contact with the outer wall of the first part, and the outer wall of the support seat is on the same axial plane as the outer wall of the second part, and the support seat is made of thermal resistance material.

9. A method for using a wafer carrier for epitaxial growth according to any one of claims 1 to 8, characterized in that: The following steps are involved: Providing a wafer carrier for epitaxial growth according to any one of claims 1 to 8; Use a vacuum pen to suck the wafer and place it into the wafer carrier, or use a robotic arm to place the wafer and the ring part onto the support part; Sending the wafer carrier carrying the wafer into an epitaxial furnace for growth; After the epitaxial growth is completed, the wafer is adsorbed by a vacuum pen, or the wafer is taken out by a robotic arm.

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