| 摘要 |
PURPOSE:To widen the safety operating region of the titled device and to upgrade the quality by a method wherein a horizontal Zener diode is formed at the P-N junction between a high-impurity concentration collector layer and a base region. CONSTITUTION:Phosphorus is diffused in an N type silicon substrate 1 added with phosphorus from one face thereof and a high-concentration (N<++> type) collector region 2 is formed. Phosphorus is again introduced by diffusion in the substrate 1 from the reverse face of the substrate 1 to the one face thereof, on the face side of which the collector region 2 has been formed, and an N<+> type layer 6 is formed. After that, apertures for base diffusion are provided on an SiO2 film 7 on the N<+> type layer 6 by performing a photo etching, and by diffusing selectively borons, which are P type impurities, through the apertures, a base region 3 is formed. After that, apertures for forming an emitter region and a ring-shaped channel intercepting region are provided on the SiO2 film 7 on the base region 3 by performing a photo etching again. As a result, by selectively diffusing phosphorus through each of these apertures, an N<++> type emitter region 4 and N<++> type channel intercepting regions 12 are formed. |
