| 摘要 |
PURPOSE:To prevent the formation of a back channel without decreasing the mobility of a channel, in an offset SOI/MOS FET, by implanting ions only in the vicinity of the bottom surface of an offset part. CONSTITUTION:On a silicon substrate 11, an SiO2 film 12, which is to become an SOI insulator, is formed. A polysilicon film 13, which is to become SOI silicon, is grown thereon (a). The film 13 is recrystallized by the projection of a laser beam 21, and a single crystal silicon film 14 is formed (b). Born is implanted in a patterned element forming regions 14a, and a p-type is obtained (c). A gate oxide film 15 is formed on the surface, polysilicon is deposited on the entire surface, a resist mask 23 is patterned and a gate electrode 16 if formed. Then, boron is implanted, and a part 19 at the bottom surface is made to a p<+> type for preventing a back channel. Then, ions are implanted in order to form an offset part 18a, and a region 20 in the vicinity of the surface of the region 14a is made to be an n-type (d). The resist mask 23 is removed, and a new resist mask 24 is formed. Phosphorus ions are implanted, and source and drain regions 17 are formed (e). |
