| 摘要 |
PURPOSE:To obtain a field effect transistor having less irregularity, small pinch- off voltage and a large conductance by forming a channel region on the surface of raised projection formed on the surface of a substrate. CONSTITUTION:Photoresists 3, 3a are covered on the regions except the base region of an N-P-N type transistor, the gate region of a field effect transistor and a gate electrode producing region, and with the photoresists as masks boron ions are implanted, and an implantation layer 4 is formed on the surface of a silicon substrate 1. The region surrounded by implantation layers 6a, 6b becomes a raised projection 20 and a region operating as a channel layer. After the layers 6a, 6b are further respectively formed in recesses 21, 21, the photoresists 3, 3a, 5 are all removed, only the vicinity of the projection 20 is allowed to remain, and a photoresist 7 is again covered. After the implantation layer 8A is then formed, the photoresist 7 is removed, an annealing and a drive-in are performed in a high temperature furnace, thereby allowing the layers 6a, 6b, 4 to respectively become diffused layers 10a, 10b, 9. Thus, when inverse biase to be applied to the region 8 and the layers 10a, 10b is incereased, a depletion layer is expanded sequentially to the boundary lines (a), (b), (c), and when the region 8 is filled with the depletion layer, it is completely pinched off. |
