SEMICONDUCTOR SUBSTRATE, FIELD-EFFECT TRANSISTOR, METHOD OF FORMING SiGe LAYER, METHOD OF FORMING STRAINED Si LAYER USING THE SAME, AND METHOD OF MANUFACTURING THE FIELD- EFFECT TRANSISTOR

摘要

PROBLEM TO BE SOLVED: To reduce through dislocation density in a semiconductor substrate, field-effect transistor, and a method of forming SiGe layer, method of forming strained Si layer using the same, and to provide method of manufacturing a field-effect transistor. SOLUTION: SiGe layers 3, 4 are provided on a Si substrate 1, where a high concentration region 2, in which impurity concentration is higher than that of the surface region of the SiGe layers, is provided on the surface of the Si substrate, or in at least a part of the inside of the SiGe layers.