| 摘要 |
PURPOSE:To avoid a discharge caused by moisture by a method wherein a P type base domain is provided to a surface layer of an N type Si substrate and, when an N<+> type emitter domain is formed in the base domain, an N<+> type guard ring domain surrounding the base domain is formed by diffusion and, when a polycrystalline Si equipotential ring is provided to the ring domain, it is covered completely with an SiO2 film. CONSTITUTION:A P type base domain 12 is formed in a surface layer of an N type Si substrate 11 by diffusiion. When an N<+> type emitter domain 13 is formed in the domain 12, an N<+> type guard ring domain 11' surrounding the domain 12 is formed by diffusion at the same time. In an SiO2 film 16 formed on the surface at that time, an aperture is drilled on the domain 11'. A polycrystalline Si equipotential ring 18 contacting the domain 11' is formed on the film 16 with its edge part extending toward the side of the domain 12. Then all of the exposed part of the ring 18 is covered with an SiO2 film 19. With this constitution, even if moisture adheres to the surface, no discharge is produced between the ring 18 and Al electrodes 15 and 14 attached to the domains 12 and 13. |
