SEMICONDUCTOR SUBSTRATE, SEMICONDUCTOR DEVICE, AND METHOD OF MANUFACTURING SEMICONDUCTOR DEVICE

摘要

PROBLEM TO BE SOLVED: To provide a semiconductor substrate which prevents boron from being diffused up to an operation layer while containing sufficient boron in a buffer layer in order to obtain the transition suppressing effect.SOLUTION: A semiconductor substrate includes: a silicon-based substrate; a buffer layer which is provided on the silicon-based substrate and made of nitride-based semiconductor containing boron; and an operation layer formed on the buffer layer. Boron concentration of the buffer layer is gradually reduced toward the operation layer side from the silicon-based side.