Silicon carbide metal-insulator semiconductor field effect transistor

(57) Abstract: u-shaped gate trenches and having an n-type silicon carbide drift layer, a silicon carbide metal Zemmidori-semiconductor field-effect transistor. p-type region is formed in the silicon carbide drift layer, and extends below the bottom of the u-shaped gate trenches, thereby preventing electric field concentration at the corner portion of the gate trench. Having n-type conductivity silicon carbide bulk single crystal silicon carbide substrate, a unit cell of a metal insulator semiconductor transistor. A first epitaxial layer of n-type conductivity silicon carbide, formed on the first epitaxial layer, a second epitaxial layer of p-type conductivity silicon carbide. The first trench extends downward, is formed in the first epitaxial layer through the second epitaxial layer. Second trenches adjacent to the first trench also extends downward, is formed in the first epitaxial layer through the second epitaxial layer. Region of n-type conductivity silicon carbide is formed between the first and second trenches, and has an upper surface opposite the second epitaxial layer. The insulator layer is formed in the first trench, the upper surface of the first gate insulator layer formed on the bottom of the trench, below the lower surface of the second epitaxial layer. The region of p-type conductivity silicon carbide is formed under the second trench in the first epitaxial layer. The gate and the source contact, each first and formed in a second trench, and is formed in contact with a drain contact on the substrate. Preferably the gate insulator layer, the transistor being formed is an oxide such that the metal oxide field effect transistor.