High electron mobility transistor

摘要

A high electron mobility transistor structure (10) is provided having an insulating substrate (12) having a substrate lattice constant. A buffer layer (14) is disposed over the substrate and has a graded lattice constant substantially equal to a first lattice constant near a bottom of the buffer layer and substantially equal to a second lattice constant near a top of the buffer layer larger than the substrate lattice constant and the first lattice constants. A channel layer (22) is disposed above the buffer layer and has a concentration of indium to provide a lattice constant of the channel layer that is larger than the substrate lattice constant.