| 摘要 |
PURPOSE:To provide a semiconductor device with improved resistance against soft errors caused by alpha ray irradiation, which enables the high speed operation of transistors. CONSTITUTION:In a semiconductor device provided with the first well 20 to compose a transistor in a memory circuit 2 and the second well 30 to compose a transistor in a peripheral circuit 3, a retrograding type well is used for the first well 20 and the second well 30. In addition these wells are formed with the junction depth d1 of the first well 20 smaller than the junction depth d2 of the second well 30. |
