Semiconductor device

Abstract

Abstract PURPOSE: To obtain excellent high-frequency characteristics with a degree of integration increased by providing a concavity into a semiconductor substrate penetrating an external base region provided to the surface layer part of the semiconductor, by diffusion-forming an internal base region connecting to the external base region on the flank of this concavity, and by providing an emitter region into it. CONSTITUTION: Onto N-type Si substrate 1, SiO 2 film 2 is adhered and provided with an opening, P + -type external base region 3 for decreasing lead-out resistance is formed by diffusion, and a SiO 2 film produced at that time is provided and opening and etched to form concavity 4 in substrate 1, so that its depth will determine the width of an emitter region. Next, SiO 2 film 5 is vapor-deposited on the entire surface and SiO 2 film 6 is produced at the bottom of concavity 4; and the both are used as a mask to form internal base region 7, connecting to region 3, on the flank of concavity 4 by diffusion. To the flank of concavity 4, polycrystal Si layer 8 including N-type impurities is formed, which is heat-treated to diffuse impurities inside it, thereby forming N-type emitter region 9 inside region 7. Next, window 10 is made in film 2 and Al emitter electrode 11 and base electrode 12 are both adhered. COPYRIGHT: (C)1979,JPO&Japio

Inventors

• 👤 Minoru Matsumoto
• 👤 Sadaichi Inaba

Bibliographic Details