Title :
Characterization of the effectiveness of carbon incorporation in SiGe for the elimination of parasitic energy barriers in SiGe HBTs
Author :
Anteney, I.M. ; Lippert, G. ; Ashburn, P. ; Osten, H.J. ; Heinemann, B. ; Parker, G.J. ; Knoll, D.
Author_Institution :
Dept. of Electron. & Comput. Sci., Southampton Univ., UK
fDate :
3/1/1999 12:00:00 AM
Abstract :
An electrical method is applied to SiGe and SiGe:C heterojunction bipolar transistors (HBTs) to extract the bandgap narrowing in the base layer and to characterize the presence of parasitic energy barriers in the conduction band, arising from boron transient enhanced out-diffusion from the SiGe layer. It is shown that a background carbon concentration within the base (/spl ap/10/sup 20/ cm/sup -3/) eliminates parasitic energy barriers at the collector/base junction, and hence shows that transient enhanced diffusion of boron from the base has been completely suppressed.
Keywords :
Ge-Si alloys; carbon; conduction bands; diffusion; energy gap; heterojunction bipolar transistors; semiconductor materials; HBT; SiGe:C; bandgap narrowing; collector/base junction; conduction band; parasitic energy barriers; transient enhanced out-diffusion; Boron; Current measurement; Density measurement; Electrical resistance measurement; Energy barrier; Germanium silicon alloys; Heterojunction bipolar transistors; Implants; Photonic band gap; Silicon germanium;
Journal_Title :
Electron Device Letters, IEEE
