Wafer carrier disk for epitaxial growth

Abstract

The utility model provides a kind of wafer bearing disc for epitaxial growth, including bearing disc ontology and coating graphite block group, the coating graphite block group is spliced by multiple sub-graphite blocks, the middle part of bearing disc ontology is recessed with graphite block mounting groove, multiple the sub-graphite blocks are spliced in the graphite block mounting groove to form multiple sub-graphite block partitions, the sub-graphite block partition is composed of at least one sub-graphite block, the sub-graphite block partition can be set to have different thickness, and thereby to change the temperature field distribution of wafer bearing disc surface area, to control the temperature of wafer each area point directly, to control the impurity doping concentration and epitaxial layer thickness of epitaxial wafer area, improve the electrical performance, yield and reliability of the device prepared.

Description

Technical Field

[0001] This utility model relates to the field of semiconductor manufacturing technology, and in particular to a wafer carrier disk for epitaxial growth. Background Technology

[0002] Silicon carbide (SiC) is the third-generation wide-bandgap semiconductor material developed after silicon (Si) and gallium arsenide (GaAs). Due to its excellent physical properties such as high critical breakdown field strength, high thermal conductivity, and high saturated electron drift velocity, it has extremely high application value in high-temperature, high-voltage, high-frequency, and high-power power electronic devices. Compared with traditional silicon devices, SiC devices have lower power loss, higher voltage withstand capability, better heat dissipation, and superior high-frequency performance.

[0003] The fabrication of high-performance silicon carbide (SiC) devices primarily relies on the homoepitaxial growth of a high-quality SiC thin film on a SiC substrate. The quality of the epitaxial layer, including defect density, thickness, and uniformity of doping concentration, directly determines the electrical performance, yield, and reliability of the device.

[0004] Silicon carbide epitaxial growth is typically carried out in specialized SiC epitaxial furnaces, with the main heating methods being induction heating and resistance heating. Induction heating: A high-frequency alternating electric field is generated by an radio frequency power supply, forming an alternating magnetic field within the reaction chamber. This magnetic field acts on conductive components such as graphite, inducing a current that generates heat due to resistance, thus achieving heating. Resistance heating: Utilizes the Joule heat (Q=I) generated when current flows through a resistive material (such as a metal resistance wire or graphite resistive body). 2 Rt) transfers heat to the object being heated through heat conduction, heat convection, or heat radiation.

[0005] In both heating methods, temperature field distribution is a key factor affecting the quality of epitaxial wafers, directly influencing core parameters such as growth rate, uniformity, and defect density. The graphite support pads and rings are closely related to heat generation and conduction, and are crucial factors affecting temperature field distribution, doping efficiency, wafer appearance, and growth rate.

[0006] With the continuous growth of market demand for silicon carbide power devices, the industry's requirements for product quality are becoming increasingly stringent. Existing graphite carrier disks and rings have gradually revealed bottlenecks in large-scale production, making it difficult to meet the demands of higher quality standards. Therefore, designing and developing new graphite carrier disks and rings has become an urgent need to improve the quality of silicon carbide epitaxial wafers. Utility Model Content

[0007] Therefore, in response to at least one of the above problems, this utility model provides a wafer carrier disk for epitaxial growth.

[0008] This utility model is achieved using the following solution: This invention proposes a wafer carrier disk for epitaxial growth, including a carrier disk body and a coated graphite block assembly. The coated graphite block assembly is composed of multiple sub-graphite blocks. A graphite block mounting groove is recessed in the middle of the carrier disk body. Multiple sub-graphite blocks are assembled in the graphite block mounting groove to form multiple sub-graphite block partitions. Each sub-graphite block partition consists of at least one sub-graphite block. The sub-graphite block partitions can be set to have different thicknesses, thereby changing the temperature field distribution of the wafer carrier disk surface area.

[0009] In one embodiment, the sub-graphite blocks have different thicknesses, such that the sub-graphite block partitions have different thicknesses.

[0010] In one embodiment, the number of sub-graphite blocks contained in the sub-graphite block partition is not the same, thereby making the sub-graphite block partition have different thicknesses.

[0011] In one embodiment, the sub-graphite block is rectangular, and the sub-graphite block is partitioned in a rectangular checkerboard pattern.

[0012] In one embodiment, a support ring is provided on the bearing disk body, and the support ring is arranged around the periphery of the graphite block mounting groove.

[0013] In one embodiment, the wafer carrier disk further includes a coated graphite ring. The carrier disk body has an outer peripheral edge on the outer periphery of the support ring. The support ring is higher than the outer peripheral edge, and the outer peripheral edge and the support ring are used to position and install the coated graphite ring. The upper surface of the coated graphite ring is higher than the upper surface of the support ring.

[0014] In one embodiment, a positioning and mating structure consisting of a boss and a groove is provided on the contact surfaces of the bearing disk body and the coated graphite ring.

[0015] In one embodiment, the upper surface of the outer peripheral edge of the bearing disk body is recessed with a positioning groove, and the lower surface of the coated graphite ring is protruded with a positioning pin. The positioning pin can be slidably inserted into the positioning groove and cooperate with each other for positioning.

[0016] In one embodiment, the outer edge of the coated graphite ring extends axially downward with an annular flange, which can be fitted onto the outside of the support disk body.

[0017] In one embodiment, the inner side of the coated graphite ring is provided with a limiting portion, and the support ring is provided with a limiting fitting portion that cooperates with it.

[0018] The technical solution provided by this utility model has the following technical effects: 1. This utility model provides a wafer carrier disk for epitaxial growth, including a carrier disk body and a coated graphite block assembly. The coated graphite block assembly is composed of multiple sub-graphite blocks spliced ​​together. A graphite block mounting groove is recessed in the middle of the carrier disk body. Multiple sub-graphite blocks are spliced ​​in the graphite block mounting groove to form multiple sub-graphite block partitions. Each sub-graphite block partition consists of at least one sub-graphite block. The sub-graphite block partitions can be set to have different thicknesses, thereby changing the temperature field distribution of the wafer carrier disk surface area. This allows for direct temperature control of various points on the wafer, thereby controlling the impurity doping concentration and epitaxial layer thickness in the epitaxial wafer area, and improving the electrical performance, yield, and reliability of the fabricated device.

[0019] 2. The wafer carrier also includes a coated graphite ring. The upper surface of the coated graphite ring is higher than the upper surface of the support ring. The design of the support ring and the coated graphite ring can prevent the wafer from directly contacting the graphite carrier, reduce the friction between the wafer and the graphite carrier, reduce the probability of graphite powder being deposited on the back side of the wafer after volatilization, and at the same time effectively block the source gas, reduce the probability of source gas entering the back side of the wafer, and reduce the occurrence of deposition.

[0020] 3. A positioning and mating structure with bosses and grooves is provided on the contact surfaces of the carrier disk body and the coated graphite ring, so that the carrier disk body and the coated graphite ring are positioned, avoiding relative rotational motion between the coated graphite ring and the carrier disk body. This reduces the impact of particulate matter generated by relative friction between the carrier disk body and the coated graphite ring on the downfall defects on the wafer front side, thereby improving wafer yield. Attached Figure Description

[0021] Figure 1 This is a perspective view of the chip carrier disk according to an embodiment of the present invention; Figure 2 This is an exploded view of the wafer carrier disk in this embodiment; Figure 3 This is a full cross-sectional view of the wafer carrier disk in this embodiment. Figure 4 yes Figure 3 Enlarged view of point A in the middle; Figure 5 This is a perspective view of the carrier disk body in this embodiment; Figure 6 This is a perspective view of the coated graphite ring of this embodiment; Figure 7 yes Figure 6 Enlarged view of point B in the middle. Detailed Implementation

[0022] To further illustrate the various embodiments, the present invention provides accompanying drawings. These drawings are part of the disclosure of the present invention and are mainly used to illustrate the embodiments, and can be used in conjunction with the relevant descriptions in the specification to explain the operating principles of the embodiments. With reference to these drawings, those skilled in the art should be able to understand other possible implementations and the advantages of the present invention. Components in the drawings are not drawn to scale, and similar component symbols are generally used to represent similar components.

[0023] The present invention will now be further described in conjunction with the accompanying drawings and specific embodiments.

[0024] like Figures 1-7 As shown, this embodiment provides a wafer carrier disk 1 for epitaxial growth, including a carrier disk body 10, a coated graphite block assembly 20, and a coated graphite ring 30. A graphite block mounting groove 11 is recessed in the middle of the carrier disk body 10, and the coated graphite block assembly 20 is installed in the graphite block mounting groove 11. The coated graphite block group 20 is composed of multiple sub-graphite blocks 21a and 21b. The multiple sub-graphite blocks 21a and 21b are spliced ​​in the graphite block mounting groove 11 of the carrier disk body 10 to form multiple sub-graphite block partitions 23a and 23b. Sub-graphite block partitions 23a and 23b can be composed of at least one sub-graphite block 21a and 21b. Sub-graphite block partitions 23a and 23b can have the same or different thicknesses. When the sub-graphite block partitions 23a and 23b are set to have different thicknesses, the temperature field distribution of the disk surface area of ​​the wafer carrier disk 1 can be changed, thereby directly controlling the temperature of each point in the wafer, thereby controlling the impurity doping concentration and epitaxial layer thickness in the epitaxial wafer area, and improving the electrical performance, yield and reliability of the fabricated device.

[0025] The thicknesses of the sub-graphite blocks 21a and 21b can be different, so that the sub-graphite block partitions 23a and 23b have different thicknesses; or, the number of sub-graphite blocks 21a and 21b contained in the sub-graphite block partitions 23a and 23b can be different, and different numbers of sub-graphite blocks 21a and 21b are stacked so that the sub-graphite block partitions 23a and 23b have different thicknesses.

[0026] In this embodiment, the sub-graphite blocks 21a and 21b are designed as rectangular blocks, and the sub-graphite block partitions 23a and 23b are distributed in a rectangular checkerboard pattern, which can achieve more precise temperature control. In other embodiments, the sub-graphite blocks can also be ring-shaped, cubic, polyhedral, etc.

[0027] During silicon carbide epitaxial growth, graphite powder volatilization and the entry of source gas into the back side of the wafer can both cause deposition on the back side, resulting in poor appearance of the epitaxial wafer. Therefore, in this embodiment, a support ring 12 is also provided on the carrier disk body 10, and the support ring 12 is arranged around the periphery of the graphite block mounting groove 11. The carrier disk body 10 has an outer peripheral edge 13 on the outer periphery side of the support ring 12. The support ring 12 is higher than the outer peripheral edge 13 of the carrier disk body 10, and the outer peripheral edge 13 and the support ring 12 can be used to position and install the coated graphite ring 30. The upper surface of the coated graphite ring 30 is higher than the upper surface of the support ring 12. The design of the support ring 12 and the coated graphite ring 30 can prevent the wafer from directly contacting the graphite carrier disk, reduce the friction between the wafer and the graphite carrier disk, reduce the probability of graphite powder being deposited on the back side of the wafer after volatilization, and at the same time, effectively block the source gas, reduce the probability of the source gas entering the back side of the wafer, and reduce deposition.

[0028] In this embodiment, an annular flange 31 extends axially downward from the outer edge of the coated graphite ring 30. The annular flange 31 can be fitted onto the outer side of the carrier disk body 10. The annular flange 31 can position the coated graphite ring 30 on the carrier disk body 10, thereby improving the stability of the installation between the coated graphite ring 30 and the carrier disk body 10. The annular flange 31 can also further block the source gas, reducing the probability of the source gas entering the back side of the wafer and reducing the occurrence of deposition.

[0029] During the growth process, the carrier disk body 10, the coated graphite ring 30, and the wafer on the carrier disk all need to rotate at a uniform speed. If relative rotation occurs between the coated graphite ring 30 and the carrier disk body 10 during rotation, particles generated by friction between them may fall onto the wafer substrate surface, causing defects. The design of the support ring 12 can mitigate this situation. Furthermore, in this embodiment, a positioning and mating structure with bosses and grooves is provided on the contact surfaces of the carrier disk body 10 and the coated graphite ring 30, so that the carrier disk body 10 and the coated graphite ring 30 are positioned, avoiding relative rotation between the coated graphite ring 30 and the carrier disk body 10. This reduces the impact of particles generated by relative friction between the carrier disk body 10 and the coated graphite ring 30 on wafer downfall defects, thereby improving wafer yield.

[0030] In this embodiment, a positioning groove 14 is recessed on the upper surface of the outer peripheral edge 13 of the bearing disk body 10, and a positioning pin 32 is protruded on the lower surface of the coated graphite ring 30. The positioning pin 32 can be slidably inserted into the positioning groove 14 and cooperate with each other for positioning, so that a positioning is formed between the bearing disk body 10 and the coated graphite ring 30. There can be at least two positioning pins 32 and positioning grooves 14. In this embodiment, four positioning pins 32 and four positioning grooves 14 are shown.

[0031] The inner side of the coated graphite ring 30 is provided with a limiting part 33, and the support ring 12 is provided with a limiting mating part 121 that cooperates with it. The limiting part 33 can limit the installation of the coated graphite ring 30 on the bearing plate body 10 in the circumferential direction, making the assembly between the two more convenient and making it easier to align the positioning pin 32 with the positioning groove 14 to form a mating positioning.

[0032] The wafer carrier 1 provided in this embodiment is described using the example of placing a 6-inch wafer. However, it is not limited to this. It can also be adjusted to place wafers of 4-inch, 8-inch, 12-inch and above as needed. That is, the wafer carrier 1 provided in this embodiment does not limit the size of the wafers placed on it.

[0033] Although the present invention has been specifically shown and described in conjunction with preferred embodiments, those skilled in the art should understand that various changes in form and detail may be made to the present invention without departing from the spirit and scope of the present invention as defined in the appended claims, and all such changes shall be within the scope of protection of the present invention.

Claims

1. A wafer carrier disk for epitaxial growth comprising a carrier disk body, characterized by, It also includes a coated graphite block group, which is composed of multiple sub-graphite blocks spliced ​​together. A graphite block mounting groove is recessed in the middle of the carrier disk body. Multiple sub-graphite blocks are spliced ​​in the graphite block mounting groove to form multiple sub-graphite block partitions. Each sub-graphite block partition consists of at least one sub-graphite block. The sub-graphite block partitions can be set to have different thicknesses, thereby changing the temperature field distribution of the wafer carrier disk surface area.

2. The wafer boat of claim 1, wherein: The sub-graphite blocks have different thicknesses, so that the sub-graphite block partitions have different thicknesses.

3. The wafer boat of claim 1, wherein: The number of sub-graphite blocks contained in the sub-graphite block partitions is not the same, thus making the sub-graphite block partitions have different thicknesses.

4. The wafer carrier disk according to claim 1, characterized in that: The sub-graphite blocks are rectangular blocks, and the sub-graphite blocks are divided into sections in a rectangular checkerboard pattern.

5. The wafer carrier disk according to claim 1, characterized in that: The support ring is provided on the bearing plate body and is arranged around the periphery of the graphite block mounting groove.

6. The wafer carrier disk according to claim 5, characterized in that: The wafer carrier disk also includes a coated graphite ring. The carrier disk body has an outer peripheral edge on the outer periphery of the support ring. The support ring is higher than the outer peripheral edge, and the outer peripheral edge and the support ring are used to position and install the coated graphite ring. The upper surface of the coated graphite ring is higher than the upper surface of the support ring.

7. The wafer carrier disk according to claim 6, characterized in that: The contact surfaces of the bearing disk body and the coated graphite ring are provided with a positioning and mating structure consisting of a boss and a groove.

8. The wafer carrier disk according to claim 7, characterized in that: The upper surface of the outer peripheral edge of the bearing disk body is recessed with a positioning groove, and the lower surface of the coated graphite ring is protruded with a positioning pin. The positioning pin can be slidably inserted into the positioning groove and cooperate with each other for positioning.

9. The wafer carrier disk according to claim 6, characterized in that: The outer edge of the coated graphite ring extends axially downward with an annular flange, which can be fitted onto the outside of the bearing disk body.

10. The wafer carrier disk according to claim 6, characterized in that: The inner side of the coated graphite ring is provided with a limiting part, and the support ring is provided with a limiting mating part that cooperates with it.

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