Title :
Current gain-Early voltage products in graded-base Si/Si1-x Gex/Si heterojunction bipolar transistors
Author :
Prinz, E.J. ; Sturm, James C.
Author_Institution :
Dept. of Electr. Eng., Princeton Univ., NJ
fDate :
12/1/1991 12:00:00 AM
Abstract :
Summary form only given. An examination is made of the current-gain-Early-voltage (β-VA) tradeoff for graded base Si/Si1-xGex/Si heterojunction bipolar transistors (HBTs). A two-layer stepped-based structure was used to achieve a βVA product greater than 100000 V at room temperature for a device predicted to have a cutoff frequency in excess of 10 GHz. This is an improvement of this figure of merit by a factor greater than 20. It is shown that the Early voltage in a bipolar transistor can be improved dramatically by inserting a thin heavily doped p+-SiGe layer at the collector side of the base, without any reduction in gain
Keywords :
Ge-Si alloys; heterojunction bipolar transistors; semiconductor device models; silicon; solid-state microwave devices; 10 GHz; Early voltage; HBTs; Si-Si1-xGex-Si; current gain-Early voltage product; figure of merit; graded-base; heterojunction bipolar transistors; model; room temperature; thin heavily doped p+-SiGe layer; two-layer stepped-based structure; Boron; Electrons; Energy barrier; Germanium silicon alloys; Heterojunction bipolar transistors; Hip; Infrared detectors; Silicon germanium; Solids; Voltage;
Journal_Title :
Electron Devices, IEEE Transactions on
