MOS-TYPE TRANSISTOR AND ITS MANUFACTURING METHOD

PROBLEM TO BE SOLVED: To provide a MOS-type transistor that can be manufactured readily, is capable of improving the breakdown voltage characteristic, and at the same time increasing the current drive force, and its manufacturing method. SOLUTION: A gate electrode 8 is selectively formed on a first gate insulation film 5, that is formed on the surface of a semiconductor substrate 1 and a second gate insulation film 2 that is thinner than the first gate insulation film 5. The gate electrode 8 is subjected to pattern formation so that the end part of the drain side of the gate electrode 8 is located on the thicker first gate insulation film 5. Then an N-type impurity ion-implanted to the surface of the P-type semiconductor substrate 1. For forming a low-concentration N-type source region 14 and a low-concentration N-type drain region 15, ion implantation conditions are selected so as to penetrate the first gate insulation film 5. However, for forming a high-concentration N-type source region 6 and a high-concentration N-type drain region 7, ion implantation conditions are selected so that is prevented from penetrating the first gate insulation film 5.