JPS564276A - Semiconductor device - Google Patents

Abstract

PURPOSE:To enable bi-directional operation even in an epitaxial base type semiconductor device by interposing a layer having the same conducting type as the substrate and a high impurity density between a semiconductor substrate used as a collector and a reverse conducting layer epitaxially grown to become a base on the substrate when epitaxially growing the reverse conducting type layer becoming the base on the substrate. CONSTITUTION:When epitaxially growing a P-type layer 2 becoming base region on an N-type semiconductor substrate 1 used as a collector region, it is not directly grown but an N<+>-type diffused layer 11 is interposed therebetween. In order to then increase the P-N junction surface formed between the layer 11 and the substrate 1, grooves 6 are so perforated as to enter into the substrate 1 to surround the layer 2, and an N<+>-type diffused region 5 is formed from the side surface to the bottom surface. Thereafter, an N<+>-type emitter region 4 is diffused in the layer 2 surrounded by the region 5, a P<+>-type contact region 3 is diffused adjacent to the region 4, elecrodes 9 and 10 are mounted thereon, and an electrode 8 is coated on the back surface of the substrate 1. In this manner, carrier can be sufficiently implanted to the collector even in reverse operation.