| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a manufacturing method of trench type MOSFET which enables relaxation of field concentration in the upper angle portion of a trench in a source region. SOLUTION: An epitaxial layer 2 is formed on a semiconductor substrate 1 and a body part 3 is formed in the epitaxial layer 2. An LOCOS part 25 is formed on the surface of the portion of the body part 3 where a gate is intended to be formed, and the trench is so formed as to extend from about the center of the LOCOS part 25 to the epitaxial layer 2 through the body part 3. A gate oxide film 5 being formed on the inner wall of the trench 10, the material of a gate electrode 6 is buried in the trench 10 and a source region 4 is formed on the surface side of the body part so that it comes into contact with the gate oxide film 5. A source electrode 8 connecting to the source region 4 is formed and a drain electrode 9 is formed in the rear of the semiconductor substrate 1.</p> |
