Low-pressure preparation method for silicon carbide thin film epitaxy

Abstract

The invention relates to a low-pressure preparation method for a silicon carbide thin film epitaxy. The method comprises the steps that a silicon carbide substrate is placed in a reaction chamber of silicon carbide CVD equipment, and the reaction chamber is vacuumized; first hydrogen flow with a first constant flow rate is introduced into the reaction chamber, and under the first hydrogen flow andthe first constant pressure, the reaction chamber is heated to a first constant temperature; at the first constant temperature, the silicon carbide substrate placed in the reaction chamber is subjected to in-situ etching; after the reaction chamber is heated to a second constant temperature, the air pressure of the reaction chamber is adjusted to the second constant pressure, C3H8 and SiH4 are introduced into the reaction chamber, and an epitaxial layer grows on the silicon carbide substrate; under the third constant pressure, the silicon carbide substrate with the epitaxy layer growing on iscooled in second hydrogen flow with a second constant flow rate; under the fourth constant pressure, the silicon carbide substrate with the epitaxy layer growing on is cooled in the second hydrogen flow; at a third constant temperature, the silicon carbide substrate with the epitaxy layer growing on is cooled in argon flow with a third constant flow rate, and a silicon carbide epitaxy wafer is obtained.

Description

technical field [0001] The invention relates to the technical field of semiconductor device manufacturing, in particular to a method for preparing silicon carbide thin film epitaxy under low pressure. Background technique [0002] Silicon carbide has the advantages of wide band gap, high thermal conductivity, high breakdown strength, high electron saturation drift velocity, high hardness, etc., and also has strong chemical stability. These excellent physical and electrical properties make silicon carbide have many advantages in application. The forbidden band allows silicon carbide intrinsic carriers to maintain a low concentration at high temperatures, so it can work at very high temperatures. The high breakdown field strength enables silicon carbide to withstand high electric field strength, which allows silicon carbide to be used to make high-voltage, high-power semiconductor devices. The high thermal conductivity makes silicon carbide have good heat dissipation, which ...

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Problems solved by technology

Si droplets can be deposited on the substrate, leading to degradation of the epitaxial surface topography and reduction of material quality

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