| 摘要 |
PURPOSE:To improve the dimensional precision of the titled device by a method wherein, when a constant voltage diode with sandwitch construction such as p-n-p or n-p-n etc. displays a punch-through phenomenon in a base region to be the same characteristic as a yielding phenomenon, a one conductive type layer to be base region and a reverse conductive type layer located thereon are formed by ion implantation followed by forced diffusion. CONSTITUTION:A p type layer 9 is epitaxially grown on a p<+> type semiconductor substrate 8 to be changed into an SiO2 insulating and protecting film 10 by heattreating the surface layer thereof and a hole 11 is opened by photolithography. Next overall surface including the hole 11 is coated with a thin SiO2 film 12 and P ion 13 is implanted in the hole 11 within the atmosphere of high vacuum to form a shallow n<-> type implanted region 13' on the surface layer of the layer 9 exposed in the hole 11. Later the region 13 is changed into a deep region 14 by driving in at 600-700 deg.C to be further deepened by implanting B ion and driving in again forming a p<+> type region 16 in the region 14. |
