| 摘要 |
PURPOSE:To hold a shallow junction, by a method wherein an internal layer for preventing diffusion of an element region is provided by implanting impurity ions forming an electrical inactive compound against a semiconductor substrate. CONSTITUTION:A layer 2 is formed by implanting electrical inactive impurity ions such as O, N, C and the like to an Si substrate 1 at the depth just under a desired shallow junction and with high concentration. The diffusion coefficient in Si of these inactive atoms is very low and the ions are not distributed again by a thermal treatment process to compose a stable internal layer which acts as a diffusion-proof wall to the substrate inside against the active impurity atoms such as B, P, As and the like. Therefore, the formation of a shallow junction becomes possible. A source and a drain 3, 4 are provided as usual and a device is formed by high-temperature thermal treatment or by heating by laser beams 5. In this composition, a shallow junction is formed and a high-speed device is made possible. Furthermore, punch through can be prevented and further element isolation can be facilitated. |
