Semiconductor buffer structure, semiconductor device including the same, and method of manufacturing semiconductor device using semiconductor buffer structure

Abstract

A method of manufacturing a semiconductor device includes forming a silicon substrate, forming a buffer layer on the silicon substrate, and forming a nitride semiconductor layer on the buffer layer. The buffer layer includes a first layer, a second layer, and a third layer. The first layer includes AlInGaN (0≦x≦1, 0≦y≦1, 0≦x+y≦1) and has a lattice constant LP1 that is smaller than a lattice constant LP0 of the silicon substrate. The second layer is formed on the first layer, includes AlInGaN (0≦x<1, 0≦y<1, 0≦x+y<1), and has a lattice constant LP2 that is greater than LP1 and smaller than LP0. The third layer is formed on the second layer, includes AlInGaN (0≦x<1, 0≦y<1, 0≦x+y<1), and has a lattice constant LP3 that is smaller than LP2.