| 摘要 |
PURPOSE:To simplify processes by diffusing a P<+> type guard region to an inner circumferential end in an N-type ion implanting layer formed to the surface of a semiconductor substrate while one part of the guard region is overlapped, simultaneously driving in the ion implanting layer to shape an implantation region and also forming a Zener diode. CONSTITUTION:The surface of a semiconductor substrate 1 in which an N-type epitaxial layer 3 is grown on an N<+> silicon substrate 2 is coated with an silicon oxide film 4, a peripheral section is photoetched to selectively remove the silicon oxide film 4, and phosphorus, etc. are diffused selectively to shape an N<+> type contact region 5. Phosphorus ions are implanted while using the silicon oxide 4 as a mask to form an N-type ion implanting layer 6 on the surface of the substrate 1, a P<+> type guard region 8 is diffused while one part thereof is overlapped to the inner circumferential end of the layer 6, and the ion implanting layer 6 is driven in at the same time as the diffusion to shape an ion implantation region 7. A Zener diode is formed by a P<+>-N junction between the guard region 8 and the ion implantation region 7. |
