A graphite large plate applied to horizontal epitaxial cavity gas floating tail gas outlet guide channel

Abstract

The utility model belongs to the technical field of semiconductor epitaxial growth equipment, disclose a kind of graphite large tray applied to horizontal epitaxial cavity has air float tail gas flow out guide channel, including graphite large tray body, graphite large tray body is equipped with rotating pedestal disc, the rotating pedestal disc is used to place the graphite small tray of loading silicon carbide substrate, graphite large tray body inside is equipped with air float tail gas flow out guide channel, the inlet of air float tail gas flow out guide channel is connected with air float blowout hole, the outlet of air float tail gas flow out guide channel is connected with the tail gas end negative pressure extraction device of epitaxial cavity.The utility model increases air float tail gas flow out guide channel, so that air float gas is extracted from epitaxial cavity by tail gas end negative pressure after completing air float function and before being combined with growth source gas, reduce the accumulation situation of particulate matter in channel in air float gas, reduce the influence of air float gas on epitaxial wafer surface sweeping, while effectively improve the edge roughness of epitaxial wafer, and improve concentration uniformity and surface yield.

Description

Technical Field

[0001] This utility model belongs to the technical field of semiconductor epitaxial growth equipment, specifically relating to a graphite disk with an air-floating tail gas outflow guide channel applied to a horizontal epitaxial cavity. Background Technology

[0002] In the field of silicon carbide epitaxial growth, machines using air-float driven rotating base disks have become the mainstream equipment due to their high efficiency and stability. The core component of these machines is a large graphite disk on which a smaller graphite disk holds the silicon carbide substrate. Airflow released through air-float blowholes propels the rotating base disk, ensuring full contact between the substrate and the growth source gas for epitaxial growth. However, in actual operation, the air-float mechanism has significant technical bottlenecks. After the air-float airflow drives the base disk to rotate, a large amount of airflow overflows upwards from around the large graphite disk, mixing with the growth source gas and disrupting the uniformity of airflow distribution within the reaction chamber. This directly leads to a significant increase in roughness at the edge of the epitaxial wafer due to airflow disturbance, making it difficult to achieve the required thickness uniformity and severely impacting product performance. Simultaneously, the upward-flowing airflow carries particulate impurities from the reaction chamber, sweeping them onto the surface of the epitaxial wafer, causing surface defects and significantly reducing product yield. Given the extremely high quality requirements for silicon carbide epitaxial wafers, the existing graphite disk structure can no longer meet the needs of industrial development. It is necessary to optimize and improve the existing air flotation drive method and related structures to reduce the adverse effects of airflow on the silicon carbide epitaxial growth process and improve the quality and yield of epitaxial wafers. Utility Model Content

[0003] The purpose of this invention is to overcome the shortcomings of the existing technology and provide a graphite disk with an air flotation tail gas outflow guide channel applied to a horizontal epitaxial cavity. By improving the internal structure of the graphite disk and adjusting the disposal method of the air flotation gas after completing the air flotation function, the air flotation tail gas and the growth source gas are combined to avoid adverse effects on the quality of the epitaxial wafer.

[0004] To achieve the above objectives, the technical solution adopted by this utility model to solve its technical problems is as follows: a graphite disk with an air-floating tail gas outflow guide channel applied to a horizontal epitaxial cavity, comprising a graphite disk body, a rotating base disk on the graphite disk body, the rotating base disk being used to place a graphite small disk loaded with a silicon carbide substrate, and multiple air-floating tail gas outflow guide channels inside the graphite disk body, the inlet of the air-floating tail gas outflow guide channel being connected to an air-floating blow-out hole, and the outlet of the air-floating tail gas outflow guide channel being connected to a tail gas end negative pressure extraction device of the epitaxial cavity, so that the air-floating gas is extracted from the epitaxial cavity by the tail gas end negative pressure before merging with the growth source gas after completing the air-floating function.

[0005] In a preferred embodiment of this utility model, the air flotation tail gas outlet guide channel includes a horizontal channel and a vertical through hole. The horizontal channel is designed as a slope, and the vertical through hole can be a vertical through hole or an inclined through hole.

[0006] In a preferred embodiment of this utility model, the plurality of air flotation tail gas outlet guide channels are arranged at corresponding positions on the same side or both sides of the graphite disk body, and the arrangement at corresponding positions on both sides can ensure the stability of the rotating disk.

[0007] In a preferred embodiment of this utility model, the number of air-floating tail gas outflow guide channels inside the graphite disk body can be increased or decreased according to the actual epitaxial wafer size requirements.

[0008] After the air flotation gas completes its function of driving the rotating base disk, it is guided through the horizontal inclined channel and extracted from the extension cavity through the vertical through hole by utilizing the negative pressure at the tail gas end, thus preventing the air flotation tail gas from flowing upward and merging with the growth source gas.

[0009] Compared with the prior art, this technical solution has the following advantages:

[0010] 1. This utility model adds a guide channel for the outflow of air flotation tail gas, so that the air flotation gas is drawn out of the epitaxial cavity by the negative pressure at the tail gas end before it merges with the growth source gas after completing the air flotation function. This reduces the accumulation of particulate matter in the air flotation gas in the channel, reduces the purging effect of the air flotation gas on the surface of the epitaxial wafer, and effectively improves the edge roughness of the epitaxial wafer, as well as the concentration uniformity and surface yield.

[0011] 2. The graphite disk of this utility model can increase or decrease the number of air flotation tail gas outflow guide channels according to the actual epitaxial wafer size requirements, which has high flexibility and adaptability. Attached Figure Description

[0012] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0013] Figure 1 This is a top view of the graphite disk of this utility model;

[0014] Figure 2 This is a schematic diagram of the internal structure of the graphite disk of this utility model;

[0015] In the diagram: 1-Graphite disk body, 2-Rotating base disk, 3-Air flotation tail flow guide channel, 31-Horizontal channel, 32-Vertical through hole, 4-Air flotation blowout hole. Detailed Implementation

[0016] To make the objectives, technical solutions, and advantages of this utility model clearer, the technical solutions of this utility model will be further described below in conjunction with the accompanying drawings and embodiments. These embodiments may take different forms and should not be construed as limited to the description herein. Throughout the document, the same reference numerals always represent the same elements, and similar reference numerals represent similar elements.

[0017] It should be noted that the terms "inner" refer to the side in contact with the contents, and "outer" refer to the side away from the contents, and should not be construed as a limitation on this utility model.

[0018] like Figure 1 and Figure 2 As shown, the graphite disk of this invention includes a graphite disk body 1, on which a rotating base disk 2 is provided. The rotating base disk 2 is used to place a small graphite disk loaded with a silicon carbide substrate. The graphite disk body 1 has multiple air-floating tail gas outflow guide channels 3 inside. The inlet of each air-floating tail gas outflow guide channel 3 is connected to an air-floating blowout hole 4, and the outlet of each air-floating tail gas outflow guide channel 3 is connected to a tail gas end negative pressure extraction device of the epitaxial cavity. Each air-floating tail gas outflow guide channel 3 includes a horizontal channel 31 and a vertical through hole 32. The horizontal channel 31 is designed as a ramp, and the vertical through hole 32 can be either a vertical through hole or an inclined through hole. The multiple air-floating tail gas outflow guide channels 3 are located at corresponding positions on the same side or both sides of the graphite disk body 1. The number of air-floating tail gas outflow guide channels 3 inside the graphite disk body 1 can be increased or decreased according to the actual epitaxial wafer size requirements. During use, the flotation gas is blown out from the flotation blowout hole 4, which drives the rotating base disk 2 to rotate. After completing the flotation function, the flotation gas enters the flotation tail gas outflow guide channel 3 and is extracted from the epitaxial cavity by the tail gas end negative pressure extraction device through the horizontal channel 31 and the vertical through hole 32. This reduces the impact of the flotation gas on the surface of the epitaxial wafer, effectively improves the edge roughness of the epitaxial wafer, and improves the concentration uniformity and surface yield.

[0019] After the air flotation gas completes its function of driving the rotating base disk, it is guided through the horizontal inclined channel and extracted from the extension cavity through the vertical through hole by utilizing the negative pressure at the tail gas end, thus preventing the air flotation tail gas from flowing upward and merging with the growth source gas.

[0020] The graphite disk of this invention has a simple structure and reasonable design, and has high practical value and promising prospects for promotion and application.

[0021] The above embodiments are only used to illustrate the technical solutions of this utility model, and are not intended to limit it. Although this utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this utility model.

Claims

1. A graphite disk with an air-floating tail gas outflow guide channel applied to a horizontally extended cavity, comprising a graphite disk body, characterized in that, The graphite disk body is provided with a rotating base disk, which is used to place the graphite disk loaded with silicon carbide substrate. The graphite disk body is provided with an air flotation tail gas outflow guide channel. The inlet of the air flotation tail gas outflow guide channel is connected to the air flotation blowout hole, and the outlet of the air flotation tail gas outflow guide channel is connected to the tail gas end negative pressure extraction device of the epitaxial cavity.

2. The graphite disk according to claim 1, characterized in that, The air flotation tail gas outlet guide channel includes a horizontal channel and a vertical through hole. The horizontal channel is designed as a slope, and the vertical through hole can be a vertical through hole or an inclined through hole.

3. The graphite disk according to claim 1, characterized in that, The multiple air flotation tail gas outflow guide channels are set at corresponding positions on the same side or both sides of the graphite disk body.

4. The graphite disk according to claim 1, characterized in that, The number of air-floating tail gas outlet guide channels inside the graphite disk body can be increased or decreased according to the actual epitaxial wafer size requirements.

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