Heterojunction bipolar transistor

Abstract

Abstract PURPOSE:To shorten the collector transit time of electrons by a method wherein a first collector layer and a second one are provided, the first collector layer is made to be a semiconductor layer lower than a base layer in impurity concen tration, and the second collector layer is made a semiconductor layer lower than the first collector layer in impurity concentration. CONSTITUTION:A base collector.depletion layer is divided into two regions in which potential gradients correspond to characteristic curves, 18 and 19. A p<+>-GaAs is introduced as a second collector layer 15 so as to make an i-GaAs of a first collector layer 14 small in a potential gradient, and furthermore the collector layer 15 is made to be high in impurity concentration so as to make the layer 15 smaller in thickness, and the thickness of the collector layer 14 is made to occupy mostly the whole base.collector depletion layer. Provided that the potential drop in the collector layer 15 is made to be equal to or less than 1.4V in the case that GaAs is used so as not to make a tunnel current flow, the problem caused by the leakage current is prevented.

Inventors

• 👤 Tadao Ishibashi
• 👤 Yoshinori Yamauchi

Bibliographic Details