| 摘要 |
PURPOSE:To reduce the ohmically contacting resistance by forming a semiconductor film on the back surface of a semiconductor substrate as one electrode film of a semiconductor device. CONSTITUTION:After a P<+> type semiconductor layer 3 is formed from the surface after an n-type epitaxially grown layer 2 is formed on an n<+> type semiconductor substrate 1a, a gate oxide film 5a is formed. After a polycrystalline silicon film 6a is then accumulated, a P-type semiconductor layer 5 is formed in a self-aligning manner, n<+> type semiconductor layer forming portion of a source region is then selectively opened, an n<+> type semiconductor layer 8 of a source region and an oxide film 5b1 are then formed, and a PSG film 5c is then accumulated thereon. Thereafter, after various heat treatments are executed, the substrate 1a is, for example, lap polished from the back surface, an undoped polycrystalline silicon layer 6b is accumulated, a high density phosphorus is diffused in the polycrystalline silicon, higher density phosphorus that the substrate is diffused in the substrate in this case, thereby forming an n<++> type semiconductor layer 1b. Subsequently, an electrode leading port is formed, and metal electrodes 9a, 9b are formed. |
