| 摘要 |
PURPOSE:To manufacture devices without productivity lowering due to increased number of processes by a method wherein the first part of a first region and the second part thereof, surrounding said first part and featuring impurity concentration lower than that of the first part and an impurity profile similar to that of a well region, are produced in the same process wherein a well region is produced. CONSTITUTION:A first and second region 18, 19 to be drain and source regions for an MOS withstanding high voltages are selectively formed with a prescribed distance between them. The first and second region 18, 19 are respectively composed of first parts 18a, 19a that are of a second conductivity type and of high impurity concentration and second parts 18b, 19b of lower impurity concentration. The impurity concentration profile of the second parts 18b, 19b along the direction of thickness is similar to that of a well region 17. The first and second parts 18b, 19b respectively of the first and second region 18, 19 are formed in the same process wherein the well region 17 is produced. The first and second part 18a, 19a are formed in the same process wherein the P-MOS source/drain regions 12, 13 are produced. |
