Interfacial oxide, grain size, and hydrogen passivation effects on polysilicon emitter transistors

Author

Potyraj, Paul A. ; Chen, Dao-Long ; Hatalis, Miltiadis K. ; Greve, David W.

Author_Institution

Carnegie-Mellon Univ., Pittsburgh, PA, USA

Volume

35

Issue

8

fYear

1988

fDate

8/1/1988 12:00:00 AM

Firstpage

1334

Lastpage

1343

Abstract

The influence of several process variables on the characteristics of polysilicon emitter transistors is studied. The diffusion length of the polysilicon layer was increased using hydrogen passivation, resulting in an increase in the transistor current gain. The increase observed was less than that predicted by the T.H. Ning and R.D. Isaac (1980) transport model, especially at high emitter doping levels. Similarly, the polysilicon grain size had a smaller effect on the current gain than predicted by this model. On the other hand, an increase in the interfacial layer thickness caused a large increase in the emitter efficiency and also resulted in retarded arsenic diffusion and increased emitter resistance and base current ideality factor. The results suggest that reflection of minority carriers at the interface plays a dominant role in determining the emitter Gummel number in devices with heavily doped emitters

Keywords

bipolar transistors; elemental semiconductors; passivation; semiconductor device models; silicon; Gummel number; H₂ passivation; base current ideality factor; characteristics; diffusion length; emitter resistance; grain size; heavily doped emitters; high emitter doping levels; interfacial layer thickness; interfacial oxide; models; polycrystalline Si; process variables; reflection of minority carriers; semiconductors; transistor current gain; Grain size; Hydrogen; Logic devices; Passivation; Physics; Predictive models; Quantum mechanics; Reflection; Semiconductor process modeling; Silicon;

fLanguage

English

Journal_Title

Electron Devices, IEEE Transactions on

Publisher

ieee

ISSN

0018-9383

Type

jour

DOI

10.1109/16.2556

Filename

2556