| 摘要 |
PURPOSE:To avoid a punch-through and abnormal leakage to a semiconductor substrate of a source (or a drain) region by implanting the ions of a substance, which does not contribute to electrical characteristics in the substrate and has small mass, to the corner section of an impurity region and forming a well. CONSTITUTION:A mask material 12 to which one part of a P well forming prearranged section is bored is shaped onto an N type silicon substrate 11, and a P type impurity region 13 is formed. Al 14 corresponding to the corner section of the impurity region 13 is removed through etching, the ions of a substance, which does not contribute to electrical characteristics in the substrate and has small mass, such as proton are implanted to the impurity region 13 to form an impurity layer 15, and a P well 16 is shaped. Consequently, vacancies are generated in the impurity layer 15. As a result, boron ions in the impurity region 13 are diffused rapidly at the corner section of the P well 16 and the round breaking of the corner section is relaxed sufficiently in heat treatment as a post- process. Accordingly, an N<+> type source region 17 can be formed to the whole corner in the P well 16. |
