| 摘要 |
PROBLEM TO BE SOLVED: To form a transistor which enables high speed for signals without enlarging a transistor size in a semiconductor board plane direction by forming irregularities on the surface of a semiconductor board under a gate electrode. SOLUTION: A silicon oxide film 5 is formed in a prescribed region of recessed part formation by forming a silicon oxide film 2 and a silicon nitride film 3 one by one on a silicon board 1 where an isolation layer is formed by forming a resist pattern 4 thereon, through etching a silicon nitride film 3 by using the pattern 4 as a mask and by performing heat treatment on the silicon board 1 in an oxidizing atmosphere. Then, a silicon oxide film 6 and a gate G are formed by forming an irregular part on a silicon board by removing the silicon nitride film 3, and the silicon oxide film 5 and impurities are subjected to ion implantation by using the gate G as a mask. Therefore, an MOS transistor which can realize fast speed of signals passing therethrough can be formed, without making the transistor size large in a semiconductor board plane direction. |
