Heterojunction bipolar transistor

Abstract

Abstract PURPOSE:To improve a current amplification factor at a low collector current region by a method wherein an emitter-base junction interface is formed into a structure wherein the interface is moved nearer the side of a base from a heterojunction interface. CONSTITUTION:An n<+> collector contact 12, an n<-> collector 13, a p<+> base 14 and an insulating film 16 are formed on a substrate 11 by a normal method and thereafter, an emitter electrode window is opened on the film 16 and a phosphorosilicate glass film (a PSG film) 20 is grown. Then, a heat treatment is performed to diffuse an impurity and after an n-type emitter 10 is formed, the film 20 is removed. Subsequently, an N-type hydrogenerated microcrystal Si film is grown to form an n-type muc-Si:H emitter 15 and after that, electrodes 17, 18 and 19 are formed to obtain a heterojunction bipolar transistor. According to such a way, the crystallizability of an emitter-base junction interface is improved, and therefore the recombination current of carriers is reduced to increase the current amplification factor.

Inventors

• 👤 Hiroshi Fujioka
• 👤 洋 藤岡

Bibliographic Details