Title :
High frequency performance of Si1-xGex/Si1-yGey/Si1-xGex HBTs
Author :
Rosenfeld, D. ; Alterovitz, S.A.
Author_Institution :
NASA-Lewis Res. Center, Cleveland, OH, USA
Abstract :
The results of a theoretical study of the performance of high speed SiGe HBTs is presented. The study includes a group of SiGe HBTs in which the Ge concentration in the base is 20% higher than that in the emitter and collector (i.e. y=x+0.2). It is shown that the composition dependences of fT and the Fmax are non-monotonic. As the Ge composition in the emitter and collector layers is increased, fT and fmax first decrease, then remain constant and finally increase to attain their highest values.
Keywords :
Ge-Si alloys; heterojunction bipolar transistors; solid-state microwave devices; F max; Ge concentration; HBTs; HF performance; Si 1-xGe x-Si 1-yGe y; composition dependences; cutoff frequency; f T; maximum frequency of oscillation; theoretical study;
Journal_Title :
Electronics Letters
DOI :
10.1049/el:19930178
