Silicon carbide epitaxial growth device

Abstract

The invention discloses a silicon carbide epitaxial growth device. The epitaxial growth device comprises a gas supply system, the gas supply system comprises a front-end module and a rear-end module, the front-end module is used for accessing reaction gas, the output of the front-end module is connected with the rear-end module, and a gas path of the rear-end module is provided with a branch flow path matched and corresponding to at least one reaction gas type, the number of flow paths of each branch flow path is equal to the number of gas inlet cavities n of the multi-cavity spray head device, each gas path branch is provided with a pressure controller and (n-1) flow controllers, and the rear end module is used for adjusting reaction gas, carrier gas or protective gas before the multi-cavity spray head device is introduced. The flow of the gas path branches in the gas supply system is set and determined by the n-1 MFCs, and the gas flow of the path where the PC is mounted is equal to the difference between the total gas inlet flow of the front parts of the branches and the total flow of the branches where the MFCs are mounted, so that the problem that the total flow of the inlet does not accord with the total flow of the outlet is solved.

Description

technical field [0001] The present application relates to the technical field of thin film material growth, in particular to a silicon carbide epitaxial growth device. Background technique [0002] The silicon carbide CVD equipment used to prepare silicon carbide epitaxial wafers is a high-tech equipment integrating gas transportation, gas mixing, vacuum, high temperature, rotation and other technologies. When the equipment is running, the reaction gas is heated by the heater and flows to the surface of the substrate (substrate) at the reaction temperature, and a chemical reaction occurs on the surface to form a single crystal film. The gas supply system of CVD equipment is composed of a mixture of various reaction gases / carrier gases. Usually, after the reaction gases are mixed, they are sent to the intake part through a large flow of carrier gas, and then enter the reaction chamber to participate in the growth reaction. At present, the structure of the gas supply system o...

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Problems solved by technology

At present, the structure of the gas supply system of silicon carbide CVD equipment is complicated, and each branch is controlled by a flow controller. Under this structure, when the intake air volume is inconsistent with the air output volume, if the intake air volume is greater than the air output volume, the intake air pressure will decrease. If the flow rate increases, the incoming flow is limited. Conversely, when the intake air volume is smaller than the air output volume, the pressure at the front end of the flow controller will drop, and the air flow in the rear branch will be insufficient, resulting in a decrease in the flow rate of some branches. In this way, the flow control is unstable and the epitaxial wafers will be damaged. The growth environment changes greatly, the uniformity of doping concentration is poor, there is a certain memory effect, and the repeatability between batches is poor

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