Title :
SiGe-HBTs with high fT at moderate current densities
Author :
SchÜppen, A. ; Gruhle, A. ; Kibbel, H. ; Erben, U. ; König, U.
Author_Institution :
Res. Center, Daimler-Benz AG, Ulm, Germany
fDate :
7/7/1994 12:00:00 AM
Abstract :
Silicon-germanium heterojunction bipolar transistors (HBTs) have been developed with regard to high cutoff frequencies within a wide collector current range. Unity current gain frequencies fT high as 116 GHz were obtained at a collector current density of 2×105 A/cm2. In addition, the FWHM of cutoff frequency fT against collector current exceeds one and a half decades. Calculations indicate that the ratio of the collector to emitter area essentially determines the current density range of a high frequency HBT
Keywords :
Ge-Si alloys; current density; heterojunction bipolar transistors; semiconductor materials; solid-state microwave devices; 116 GHz; HBTs; SiGe; current density range; high cutoff frequencies; microwave operation;
Journal_Title :
Electronics Letters
DOI :
10.1049/el:19940774
