Silicon carbide oxidation method based on two-step microwave plasma oxidation

Abstract

The invention discloses a silicon carbide oxidation method based on two-step microwave plasma oxidation. The method comprises the steps of providing a silicon carbide substrate; placing the silicon carbide substrate into a microwave plasma generating device; introducing first oxygen-containing gas, increasing the temperature of a generated oxygen plasma to first temperature at a first heating speed, and performing low-temperature plasma oxidation under the first temperature and the first pressure; increasing the temperature of the oxygen plasma to second temperature at a second heating speed,introducing second oxygen-containing gas, and performing high temperature plasma oxidation under the second temperature and the second pressure till silicon dioxide of the preset thickness is generated; stopping introducing the oxygen-containing gas, and ending the reaction, wherein the first temperature is 300-400 DEG C, the second temperature is 700-900 DEG C, the first pressure is 100-200 mTorr, the second pressure is 700-900 mTorr, and the first heating speed is larger than the second heating speed. The oxidation efficiency of the silicon carbide can be remarkably improved, and the interface quality is effectively improved.

Description

technical field [0001] The invention belongs to the technical field of semiconductors, and in particular relates to a silicon carbide oxidation method based on two-step microwave plasma oxidation. Background technique [0002] Silicon carbide (SiC) is the third-generation semiconductor-wide bandgap semiconductor material. It has the advantages of large bandgap width, high critical breakdown field strength, and high thermal conductivity. It is an ideal material for making high-voltage and high-power semiconductor devices. SiC power Electronic devices are at the heart of next-generation high-efficiency power electronics technology. Compared with Si MOSFETs, SiC MOSFETs have smaller on-resistance, higher switching voltage, higher application frequency, and better temperature performance, and are especially suitable for power switching applications. The integrated manufacturing process of SiC MOSFET devices, especially the gate dielectric process, is a current research hotspot....

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Problems solved by technology

However, the oxidation efficiency of this method is low, especially when thicker SiO 2 layer, the oxidation time is longer, SiC and SiO 2 at the interface of SiC and SiO 2 It will still be in a thermodynamic equilibrium state, resulting in unsatisfactory interface quality

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