Air inlet shunting cavity of silicon carbide epitaxial reaction chamber

Abstract

The utility model discloses a gas inlet shunting cavity of a silicon carbide epitaxial reaction chamber, the gas inlet shunting cavity is provided with a gas inlet and a gas outlet, and at least one partition plate is arranged between the gas inlet and the gas outlet in the gas inlet shunting cavity to divide the gas inlet shunting cavity into at least two flow paths; the width of the partition plate is gradually reduced in the longitudinal direction from the gas inlet to the gas outlet, so that the partition plate has a certain inclination angle, airflow can flow in a specific direction, the concentration value of any area at the junction of the center and the edge of the epitaxial layer can be increased, the concentration uniformity effect of the epitaxial layer is improved, and the epitaxial growth quality is improved.

Description

Technical Field

[0001] The utility model belongs to the technical field of epitaxial growth equipment, and particularly relates to an intake air shunt cavity of a silicon carbide epitaxial reaction chamber. Background Art

[0002] Silicon carbide semiconductors have excellent properties such as a large bandgap width, excellent stability, high thermal conductivity, high critical breakdown field strength, and high saturated electron drift velocity, and are ideal semiconductor materials for making high-temperature, high-frequency, high-power, and high-radiation power electronic devices. The silicon carbide material used to make silicon carbide devices is usually a silicon carbide epitaxial wafer grown on a silicon carbide substrate.

[0003] Silicon carbide epitaxial growth usually adopts the CVD (chemical vapor deposition) method. Currently, most of the commercial epitaxial furnaces are horizontal reaction chamber epitaxial furnaces. During the process of silicon carbide epitaxial growth using an epitaxial furnace, especially for the growth of large-size epitaxial wafers, if the source gas intake shunt cavity in the intake structure of the epitaxial furnace is partitioned to form multiple flow paths, the distribution mode of process gases can be controlled, and the concentration of the grown epitaxial layer and various parameters can be controlled. However, this method has problems such as low concentration values in the flow path junction area, resulting in abnormal uniformity of the epitaxial layer concentration, which affects the quality of silicon carbide epitaxial growth. Summary of the Utility Model

[0004] The utility model aims at the deficiencies of the existing technology and provides an intake air shunt cavity of a silicon carbide epitaxial reaction chamber.

[0005] In order to achieve the above objectives, the technical solution of the utility model is as follows:

[0006] An intake air shunt cavity of a silicon carbide epitaxial reaction chamber, the intake air shunt cavity has a gas inlet and a gas outlet, and at least one partition is provided between the gas inlet and the gas outlet in the intake air shunt cavity to be partitioned into at least two flow paths; in the longitudinal direction from the gas inlet to the gas outlet, the width of the partition gradually decreases.

[0007] Optionally, the two side surfaces of the partition in the longitudinal direction are joined at the gas outlet to form an included angle.

[0008] Optionally, the angle of the included angle is 0.2° to 7°, more preferably 3° to 5°.

[0009] Optionally, one of the two side surfaces is arranged parallel to the side wall of the intake air shunt cavity in the longitudinal direction, and the other is inclined.

[0010] Optionally, the two side surfaces are both inclined relative to the side wall of the intake air shunt cavity in the longitudinal direction.

[0011] Optionally, two of the partition plates are provided in the intake air diversion cavity between the gas inlet and the gas outlet, and the two partition plates are arranged horizontally to separate a first side flow path, a middle flow path, and a second side flow path. At the gas inlet, the width ratio of the first side flow path, the middle flow path, and the second side flow path is 1:2 to 4:1.

[0012] Optionally, the width of at least one of the first side flow path, the middle flow path, and the second side flow path gradually increases in the longitudinal direction from the gas inlet to the gas outlet.

[0013] Optionally, the two partition plates have the same structure or a mirror-symmetrical structure.

[0014] Optionally, the partition plate is a quartz partition plate.

[0015] Optionally, the longitudinal direction is perpendicular to the surface of the carrier for carrying the substrate, and the carrier is rotatably arranged.

[0016] The beneficial effects of the present utility model are as follows:

[0017] On the premise of maintaining the gas diversion function of the source gas intake air diversion cavity, the width of the partition plate is gradually reduced in the longitudinal direction from the gas inlet to the gas outlet, so that the partition plate has a certain inclination angle, and the air flow can flow in a specific direction, which can improve the concentration value of any area at the junction of the center and the edge of the epitaxial layer, thereby improving the effect of the concentration uniformity of the epitaxial layer and improving the quality of epitaxial growth. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 FIG. is a schematic three-dimensional structure diagram of the intake air diversion cavity of a silicon carbide epitaxial reaction chamber according to an embodiment, showing the position of the partition plate in the intake air diversion cavity;

[0019] Figure 2 is Figure 1 a schematic cross-sectional structure diagram of the intake air diversion cavity of the silicon carbide epitaxial reaction chamber in;

[0020] Figures 3 to 6 is a schematic cross-sectional structure diagram of the intake air diversion cavity of a silicon carbide epitaxial reaction chamber according to other embodiments;

[0021] Figure 7 is a schematic diagram of the positional relationship between the intake air diversion cavity and the carrier according to the embodiment;

[0022] Figure 8 is a schematic cross-sectional structure diagram of the intake air diversion cavity of a silicon carbide epitaxial reaction chamber according to a comparative example. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0023] The present utility model will be further explained below in conjunction with the accompanying drawings and specific embodiments. The various drawings of the present utility model are only for illustration to more easily understand the present utility model, and its specific ratio can be adjusted according to design requirements. The up-down relationship of the relative components and the definition of the front / back in the described figures should be understood by those skilled in the art as referring to the relative positions of the components, so they can all be flipped to present the same components, and all of these should belong to the scope disclosed in this specification.

[0024] The intake air diversion chamber of the silicon carbide epitaxial reaction chamber in the embodiment is used for diverting the source gas intake of the silicon carbide epitaxial growth reaction chamber. Refer to Figure 1 and Figure 2 In the intake air diversion chamber 1, the two sides are the gas inlet a and the gas outlet b. Two partition plates 21 and 22 are arranged between the gas inlet a and the gas outlet b in the intake air diversion chamber to divide it into three flow paths. Taking the direction from the gas inlet a to the gas outlet b as the longitudinal direction y and the perpendicular direction as the transverse direction x, the partition plates 21 and 22 are arranged along the transverse direction x and extend along the longitudinal direction y, thereby dividing the intake air diversion chamber 1 into a first side flow path 11, a middle flow path 12, and a second side flow path 13. In the longitudinal direction from the gas inlet a to the gas outlet b, the widths of the partition plates 21 and 22 gradually decrease, so that the width of at least one flow path gradually increases to adjust the gas flow direction.

[0025] Among them, the partition plate has two side surfaces in the longitudinal direction y, and the two side surfaces meet at the gas outlet b to form an included angle α. In this embodiment, the partition plates 21 and 22 have a mirror-symmetrical structure. Their outer side surfaces 211 and 222 are both parallel to the side wall of the intake air diversion chamber 1 (i.e., parallel to the y-axis), and the inner side surfaces 212 and 221 are both inclined and meet the outer side surfaces 211 and 222 at the gas outlet b respectively to form an included angle α. The angle range of the included angle α is 0.2° to 7°, for example, 5°. At the gas inlet a, the width ratio of the first side flow path 11, the middle flow path 12, and the second side flow path 13 is 1:2 to 4:1, for example, 1:2.7:1. By the inclined setting of the inner side surfaces of the partition plates 21 and 22, the widths of the first side flow path 11 and the second side flow path 13 remain unchanged, and the gas is transported linearly. The width of the middle flow path 12 gradually increases, realizing the modulation of the gas flow direction in the middle flow path 12, reducing the difference between the gas concentration value in the area corresponding to the partition plates 21 and 22 outside the gas outlet b and the gas concentration value in the flow path area, thereby improving the concentration uniformity. According to the parameters of the epitaxial layer of the grown epitaxial wafer, the concentration uniformity can be further controlled to meet the requirements by adjusting the size of the angle α.

[0026] Refer to Figure 3, in another embodiment, the partition plates 21 and 22 have the same structure. Taking the partition plate 21 as an example, the outer side surface 211 and the inner side surface 212 have the same inclination degree to form an included angle α. It can be understood that the included angles between the outer side surface 211 and the inner side surface 212 and the y-axis are α / 2 respectively. Through the inclined arrangement of the partition plates 21 and 22, the widths of the first side flow path 11, the middle flow path 12, and the second side flow path 13 all gradually increase, and at the same time, the concentration uniformity of the airflow direction modulation in the first side flow path 11, the middle flow path 12, and the second side flow path 13 is realized.

[0027] Reference Figure 4 , in another embodiment, the partition plates 21 and 22 have a mirror-symmetrical structure. Their inner side surfaces 212 and 221 are both arranged parallel to the side wall of the intake air diversion cavity 1 (i.e., parallel to the y-axis), and the outer side surfaces 211 and 222 are both inclined to respectively form an included angle with the inner side surfaces 212 and 221 at the gas outlet b. Thus, the width of the middle flow path 12 remains unchanged, and the gas is transported linearly. The widths of the first side flow path 11 and the second side flow path 13 gradually increase, and the concentration uniformity of the airflow direction modulation is realized through the first side flow path 11 and the second side flow path 13.

[0028] Reference Figure 5 , in another embodiment, the partition plates 21 and 22 have the same structure. The inner side surface 212 of the partition plate 21 and the outer side surface 222 of the partition plate 22 are respectively arranged parallel to the side wall of the intake air diversion cavity 1 (i.e., parallel to the y-axis). The outer side surface 211 of the partition plate 21 and the inner side surface 221 of the partition plate 22 are both inclined to respectively form an included angle with the inner side surface 212 and the outer side surface 222 at the gas outlet b. Thus, the width of the second side flow path 13 remains unchanged, and the gas is transported linearly. The widths of the first side flow path 11 and the middle flow path 12 gradually increase, and the concentration uniformity of the airflow direction modulation is realized through the first side flow path 11 and the middle flow path 12.

[0029] Reference Figure 6 , in another embodiment, the partition plates 21 and 22 have the same structure. The outer side surface 211 of the partition plate 21 and the inner side surface 221 of the partition plate 22 are respectively arranged parallel to the side wall of the intake air diversion cavity 1 (i.e., parallel to the y-axis). The inner side surface 211 of the partition plate 21 and the outer side surface 222 of the partition plate 22 are both inclined to respectively form an included angle with the outer side surface 211 and the inner side surface 211 at the gas outlet b. Thus, the width of the first side flow path 11 remains unchanged, and the gas is transported linearly. The widths of the middle flow path 12 and the second side flow path 13 gradually increase, and the concentration uniformity of the airflow direction modulation is realized through the middle flow path 12 and the second side flow path 13.

[0030] The intake air diversion chamber 1 and the partition plates 21, 22 are made of quartz material, for example. The thickness of the partition plates is adjusted accordingly according to the length and angle of the intake air diversion chamber 1. Conventionally, a flow guide plate is provided at the gas inlet a of the intake air diversion chamber 1. The flow guide plate is provided with a plurality of flow guide holes. The source gas enters the intake air diversion chamber 1 through the flow guide plate. The longitudinal direction y is perpendicular to the surface of the carrier plate 3 for carrying the substrate in the reaction chamber. The carrier plate 3 is rotatably arranged. The gas outlet b is located above the substrate of the carrier plate, as Figure 7 shown.

[0031] Reference Figure 8 , in the intake air diversion chamber 1 of the comparative example, partition plates 23, 24 are provided to divide it into a first side flow path 11, a middle flow path 12 and a second side flow path 13 in the same way. The partition plates 23, 24 are arranged in parallel and the width in the y direction remains unchanged. Then the gas transmits linearly in the first side flow path 11, the middle flow path 12 and the second side flow path 13. Combining Figure 7 , when epitaxial wafers are grown on the substrate, since the linear transmission of the gas is difficult to cover the areas corresponding to the partition plates 23, 24, the concentration value at the junction of the center and the edge of the grown epitaxial wafer is relatively low, thus affecting the overall concentration uniformity of the epitaxial wafer. However, through the setting of the present utility model, the air flow can flow in a specific direction. By controlling the angle of the partition plate, the concentration value of any area at the junction of the center and the edge of the epitaxial layer can be increased, thereby improving the effect of the concentration uniformity of the epitaxial layer.

[0032] The above embodiments are only used to further illustrate the intake air diversion chamber of a silicon carbide epitaxial reaction chamber of the present utility model. However, the present utility model is not limited to the embodiments. Any simple modification, equivalent change and modification made to the above embodiments according to the technical essence of the present utility model all fall within the protection scope of the technical solution of the present utility model.

Claims

1. An air inlet diversion chamber for a silicon carbide epitaxial reaction chamber, characterized in that: The air inlet diversion chamber has a gas inlet and a gas outlet. At least one partition is provided between the gas inlet and the gas outlet in the air inlet diversion chamber to separate the chamber into at least two flow paths. The width of the partition gradually decreases in the longitudinal direction from the gas inlet to the gas outlet.

2. The gas inlet diversion chamber of the silicon carbide epitaxial reaction chamber according to claim 1, characterized in that: The two side surfaces of the partition in the longitudinal direction are connected at the gas outlet to form an angle.

3. The gas inlet diversion chamber of the silicon carbide epitaxial reaction chamber according to claim 2, characterized in that: The angle is between 0.2° and 7°.

4. The gas inlet diversion cavity of the silicon carbide epitaxial reaction chamber according to claim 2, characterized in that: One of the two side surfaces is arranged parallel to the side wall of the air inlet splitter cavity in the longitudinal direction, and the other is arranged obliquely.

5. The gas inlet diversion cavity of the silicon carbide epitaxial reaction chamber according to claim 2, characterized in that: The two side surfaces are both inclined relative to the side walls of the air inlet splitter cavity in the longitudinal direction.

6. The gas inlet diversion cavity of the silicon carbide epitaxial reaction chamber according to claim 1, characterized in that: Two partitions are provided in the air inlet diversion chamber between the gas inlet and the gas outlet, and the two partitions are arranged transversely to separate the first side flow path, the middle flow path and the second side flow path. At the gas inlet, the width ratio of the first side flow path, the middle flow path and the second side flow path is 1:2 to 4:

1.

7. The gas inlet diversion chamber of the silicon carbide epitaxial reaction chamber according to claim 6, characterized in that: The width of at least one of the first side flow path, the middle flow path and the second side flow path gradually increases in the longitudinal direction from the gas inlet to the gas outlet.

8. The gas inlet diversion cavity of the silicon carbide epitaxial reaction chamber according to claim 7, characterized in that: The two partitions have the same structure or a mirror-symmetrical structure.

9. The gas inlet diversion chamber of the silicon carbide epitaxial reaction chamber according to claim 1, characterized in that: The partition is a quartz partition.

10. The gas inlet diversion cavity of the silicon carbide epitaxial reaction chamber according to claim 1, characterized in that: The longitudinal direction is arranged perpendicular to the surface of a carrier plate for carrying the substrate, and the carrier plate is rotatably arranged.

Images