Method for manufacturing grooved MOSFET device based on two-step microwave plasma oxidation

A method for manufacturing a grooved MOSFET device based on a two-step microwave plasma oxidation, comprising:

• etching a grooved gate, and oxidizing silicon carbide on a surface of the grooved gate to form silicon dioxide using microwave plasma to form a grooved gate oxide layer,
• the step of forming the grooved gate oxide layer comprising:
• placing a silicon carbide substrate subjected to the grooved gate etching in a microwave plasma generating device;
• introducing a first oxygen-containing gas, heating generated oxygen plasma to a first temperature at a first heating rate, and performing low-temperature plasma oxidation at the first temperature and a first pressure;
• heating the oxygen plasma to a second temperature at a second heating rate, introducing a second oxygen-containing gas, and performing high-temperature plasma oxidation at the second temperature and a second pressure until a predetermined thickness of silicon dioxide is formed;
• stopping introducing the oxygen-containing gas, and completing reaction;
• wherein, the first temperature is 300-400° C., the second temperature is 700-900° C., the first pressure is 100-200 mTorr, the second pressure is 700-900 mTorr, and the first heating rate is greater than the second heating rate.