| 摘要 |
PURPOSE:To eliminate impurity diffusion, and to prevent the expansion of an element region and the generation of a parasitic element by leaving only semiconductor layers on a pair of surfaces facing to each other in semiconductor layers left on the side surfaces of a projecting section, removing others and dividing the semiconductor layers into two. CONSTITUTION:A semiconductor layer 17 is formed on the exposed surface of a projecting section 14 in a semiconductor substrate 11 and a polycrystalline silicon layer 18 on an silicon oxide film 15. A mask 19 is shaped, and the N type semiconductor layer 17 is formed to a predetermined shape by removing the layer 17 in the vertical direction and the polycrystalline silicon layer 18 to a prescribed shape by selectively removing the layer 18. N type semiconductor layers 17A, 17B are formed, and an silicon oxide film 20, a mask 21 for etching, a polycrystalline silicon layer 22, a source wiring 23, a drain wiring 24 and a gate electrode 25 are shaped. Since there is no process for impurity diffusion, a crystal is not damaged, and yield can be improved. Parasitic elements are decreased largely, and the trouble of an element function due to high voltage applied to other sections in the substrate 11 is reduced markedly. |
