JPS5743460A - Semiconductor device - Google Patents

Abstract

PURPOSE:To pervent the breakdown of an oxidized film under an input wire by decreasing VCBO by providing a buried layer in a longitudinal P-N-P transistor for an integrated circuit. CONSTITUTION:After an n type impurity is selectively introduced for n<+> type buried layers 7, 7a on a p type substrate 1, an n type epitaxial layer 3 is grown. After a p type isolation region 2 is formed, p type impurity is introduced to simultaneously form a base region 4 in an N-P-N transistor and an emitter region 8 and an extending collector region 8a in a P-N-P transistor. Then, an n type impurity is introduced to form emitter and base contacting regions 5, 10. Since the layers 7a, 7 and regions 8a, 4 are accordingly simultaneously formed in the part except the part directly under the emitter region 8 of the P-N-P transistor, the VCBO of both the transistors become approximately equal.