Title :
MBE-grown Si/SiGe HBTs with high beta , f/sub T/, and f/sub max/
Author :
Gruhle, A. ; Kibbel, H. ; König, U. ; Erben, U. ; Kasper, E.
Author_Institution :
Daimler-Benz Res. Center, Ulm, Germany
fDate :
4/1/1992 12:00:00 AM
Abstract :
Si/SiGe heterojunction bipolar transistors (HBTs) were fabricated by growing the complete layer structure with molecular beam epitaxy (MBE). The typical base doping of 2*10/sup 19/ cm/sup -3/ largely exceeded the emitter impurity level and led to sheet resistances of about 1 k Omega / Square Operator . The devices exhibited a 500-V Early voltage and a maximum room-temperature current gain of 550, rising to 13000 at 77 K. Devices built on buried-layer substrates had an f/sub max/ of 40 GHz. The transit frequency reached 42 GHz.<>
Keywords :
Ge-Si alloys; elemental semiconductors; heterojunction bipolar transistors; molecular beam epitaxial growth; semiconductor growth; silicon; solid-state microwave devices; 295 K; 40 GHz; 42 GHz; 500 V; 77 K; Early voltage; HBTs; MBE; Si-SiGe; base doping; buried-layer substrates; current gain; emitter impurity level; heterojunction bipolar transistors; molecular beam epitaxy; sheet resistances; transit frequency; Boron; Doping; Epitaxial growth; Frequency; Germanium silicon alloys; Heterojunction bipolar transistors; Impurities; Molecular beam epitaxial growth; Silicon germanium; Substrates;
Journal_Title :
Electron Device Letters, IEEE
