Tray for epitaxy and epitaxy equipment
By designing a liftable support column on the epitaxial pallet, the thermal conductivity at the ends is the same as or close to that of the pallet body, the problem of uneven epitaxial layer thickness is solved and a more uniform epitaxial layer thickness is achieved.
Patent Information
- Application Number
- CN202411890807.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-20
- Publication Date
- 2025-04-15
AI Technical Summary
In the prior art, the thickness of the epitaxial layer cannot be uniform, resulting in a change in thickness from the center to the surroundings, affecting the implementation of subsequent processes.
An epitaxial pallet is designed, including a pallet body and a liftable support column. The thermal conductivity at the end of the support column is the same as or close to the thermal conductivity of the pallet body to ensure that the overall thermal environment of the pallet body is consistent.
Through this design, the temperature of the supporting column position is avoided to be lower than the perimeter, and the epitaxial layer thickness is prevented from deviating at the supporting column position, thereby improving the uniformity of the epitaxial layer thickness.
Smart Images
Figure CN119824529A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the field of semiconductor equipment, and in particular to an epitaxial tray and an epitaxial equipment. Background Art
[0002] Silicon epitaxy refers to the process of growing homogeneous epitaxial layers on a silicon substrate. This process is usually carried out at high temperature through a gas phase chemical reaction, using a polished silicon single crystal as a substrate. By controlling the growth conditions, an epitaxial layer with good crystal quality and consistent thickness can be obtained. Silicon epitaxial materials are important basic materials used in the manufacture of various silicon integrated circuits and discrete devices, especially in large-diameter silicon integrated circuit chip production lines, where silicon epitaxy is a commonly used starting material.
[0003] However, in the prior art, we have found that the thickness of the epitaxial layer cannot be uniform, and there will be a thickness change from the center to the periphery, which will affect the implementation of subsequent processes. Therefore, how to obtain an epitaxial layer with uniform thickness is a problem that the prior art needs to solve. Summary of the invention
[0004] The technical problem to be solved by the present invention is to provide an epitaxial tray and an epitaxial device, which can improve the uniformity of the thickness of the epitaxial layer.
[0005] In order to solve the above problems, the present invention provides an epitaxial tray, including: a tray body; a plurality of support columns, which are liftably arranged in the through holes of the tray body to support wafers, and the thermal conductivity of the ends of the support columns is the same as or close to the thermal conductivity of the tray body.
[0006] Optionally, the tray is made of graphite coated with SiC, and the end material of the support column is SiC.
[0007] Optionally, the end of the support column is flat.
[0008] Optionally, there are three support columns, which are arranged in the tray body in a triangular support manner.
[0009] Optionally, the thermal conductivity of the end of the support column is greater than the thermal conductivity of the column body of the support column.
[0010] In order to solve the above problems, the present invention provides an epitaxial device, including: a tray for placing wafers; a heater for heating the wafers from the top and bottom of the tray by thermal radiation; the tray includes: a tray body; a plurality of support columns, the support columns are liftably arranged in the tray body, for supporting the wafers, and the thermal conductivity of the ends of the support columns is the same as or close to the thermal conductivity of the tray body.
[0011] Optionally, the tray is made of graphite coated with SiC, and the end material of the support column is SiC.
[0012] Optionally, the end of the support column is flat.
[0013] Optionally, there are three support columns, which are arranged in the through holes of the tray body in a triangular support manner.
[0014] Optionally, the thermal conductivity of the end of the support column is greater than the thermal conductivity of the column body of the support column.
[0015] The present invention sets the thermal conductivity of the end of the support column to be the same as or close to the thermal conductivity of the tray body, so that during the heating process, the thermal environment of the entire tray body is the same, and no thickness deviation occurs at the position of the support column. BRIEF DESCRIPTION OF THE DRAWINGS
[0016] Attached Figure 1 Shown is a schematic structural diagram of a specific implementation of the epitaxial device of the present invention.
[0017] Attached Figure 2 Shown is a top view of a tray of a specific embodiment of the epitaxial apparatus of the present invention. DETAILED DESCRIPTION
[0018] The specific implementation of the epitaxial tray and epitaxial equipment provided by the present invention will be described in detail below with reference to the accompanying drawings.
[0019] Attached Figure 1 The figure is a schematic structural diagram of a specific implementation mode of the epitaxial device of the present invention, which includes: a tray 10 and a heater 11.
[0020] The tray 10 is used to place the wafer 13. The heater 11 includes an upper heater 11a and a lower lower heater 11b. The upper and lower heaters can be a combination of one or more, and in the present specific embodiment, a combination of multiple, and the wafer 13 is heated from the middle and the edge respectively. The upper heater 11a and the lower lower heater 11b heat the wafer 13 from the upper and lower parts of the tray 10 by thermal radiation. The material of the tray 10 is graphite coated SiC. The wafer 13 can be a wafer 13 of any common semiconductor material including silicon, germanium, silicon carbide, GaAs, and GaN. The epitaxial material on the surface can be a homogeneous epitaxial layer, or a heterogeneous epitaxial layer such as GaN, GaAs, and stressed silicon. The tray 10 can be rotating or stationary, and the upper heater 11a and the lower lower heater 11b can also be independently set to rotate synchronously with the tray 10 or remain relatively stationary.
[0021] The tray 10 includes a tray body 101 and a plurality of support columns 102. The support columns 102 are arranged in the tray body 101 in a liftable manner to support the wafer 13. Figure 2 1 is a top view of the tray 10. In this specific embodiment, there are three support columns 102, which are arranged in the tray body 101 in a triangular support manner. The support columns 102 are used for loading and unloading wafers 13. When the wafer 13 enters the epitaxial device and needs to be removed after growth, the support columns 102 are raised so that the robot can lift the wafer 13. During the epitaxial growth process, the support columns 102 are in a state of being lowered to the inside of the tray body 101. During the epitaxial growth process, the process of the heater 11 heating the wafer 13 is carried out by heat radiation from the tray body 101. Studies have found that if the support column 102 is made of ordinary quartz material, then the thermal conductivity of the graphite material of the tray 10 is too different, which will cause the temperature at the position of the support column 102 to be lower than the surrounding area, and then the thickness of the epitaxial layer at this position will deviate. Therefore, in this specific embodiment, the thermal conductivity of the end of the support column 102 is set to be the same as or close to the thermal conductivity of the tray body 101. In this way, during the heating process, the thermal environment of the tray body 101 as a whole is the same, and no thickness deviation will occur at the position of the support column 102. The close setting principle is that during the epitaxial process, the deviation of the thickness at this position from the thickness at other positions is within a tolerable range. For example, if the material of the tray 10 is graphite coated with SiC, the end material of the support column 102 is SiC. SiC can be obtained by carbonizing the surface of a quartz material, and is therefore a preferred embodiment.
[0022] Preferably, in this specific embodiment, the end of the support column 102 is a flat head. This setting can keep the heat radiation environment of the end consistent. Other shapes such as round heads will cause greater heat loss in the raised part and cause temperature deviation. The flat head can ensure that the temperature of all areas at the end of the support column 102 is consistent, so it is a preferred embodiment.
[0023] The above also provides a specific implementation of an epitaxial tray, including: a tray body and a plurality of support columns, wherein the support columns are liftably arranged in the through holes of the tray body for supporting wafers, and the thermal conductivity of the ends of the support columns is the same as or close to the thermal conductivity of the tray body.
[0024] The above is only a preferred embodiment of the present invention. It should be pointed out that ordinary technicians in this technical field can make several improvements and modifications without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.
Claims
1. An epitaxial tray, characterized in that: include: Tray body; A plurality of support columns are provided in a liftable manner in the through holes of the tray body for supporting the wafers, and the thermal conductivity of the ends of the support columns is the same as or close to the thermal conductivity of the tray body.
2. The tray for extension according to claim 1, characterized in that: The material of the tray is graphite coated with SiC, and the material of the end of the support column is SiC.
3. The tray for extension according to claim 1, characterized in that: The end of the support column is a flat head.
4. The tray for extension according to claim 1, characterized in that: There are three support columns, which are arranged in the tray body in a triangular support manner.
5. The tray for extension according to claim 1, characterized in that: The thermal conductivity of the end of the support column is greater than the thermal conductivity of the column body of the support column.
6. An epitaxial device comprising: A tray for placing wafers; A heater that heats the wafer from above and below the tray by means of thermal radiation; Characterized in that the tray comprises: Tray body; A plurality of support columns are liftably arranged in a tray body for supporting wafers, and the thermal conductivity of the ends of the support columns is the same as or close to the thermal conductivity of the tray body.
7. The epitaxial device according to claim 6, characterized in that: The material of the tray is graphite coated with SiC, and the material of the end of the support column is SiC.
8. The epitaxial device according to claim 6, characterized in that: The end of the support column is a flat head.
9. The epitaxial device according to claim 6, characterized in that: There are three support columns, which are arranged in the through hole of the tray body in a triangular support manner.
10. The epitaxial device according to claim 6, characterized in that: The thermal conductivity of the end of the support column is greater than the thermal conductivity of the column body of the support column.