HETEROJUNCTION FIELD EFFECT TRANSISTORS USING SILICON-GERMANIUM AND SILICON-CARBON ALLOYS

摘要

SEMICONDUCTOR DEVICES, E.G., HETEROJUNCTION FIELD EFFECT TRANSISTORS, FABRICATED WITH SILICON-GERMNANIUM BUFFER LAYER AND SILICON-CARBON CHANNEL LAYER STRUCTURES. THE INVENTION PROVIDES A METHOD OF REDUCING THREADING DEFECT DENSITY VIA REDUCING GERMANIUM CONTENT IN A SIGE RELAXED BUFFER LAYER ON WHICH A STRAINED SILICON CHANNEL LAYER IS FORMED, BY FORMING THE STRAINED SILICON CHANNEL LAYER OF A SILICON-CARBON ALLOY, E.G., CONTAINING LESS THAN ABOUT 1.5 ATOMIC % C SUBSTITUTIONALLY INCORPORATED IN THE SI LATTICE OF THE ALLOY.