Patent ID: 8044432
Filing Date: 2011-10-25
Classification: H01L

Abstract:
1. A field-effect transistor, comprising: a source contact and a drain contact; a channel, in a vertically inhomogeneous semiconductor material having at least two layers, a top layer of the at least two layers overlain by a gate, wherein the gate is disposed between the source contact and the drain contact; the top layer of said vertically inhomogeneous semiconductor material having a higher aluminum fraction than an other layer of the at least two layers and a wider bandgap than the other layer; and a first fixed negative ion region and a second permanently fixed negative ion region within the top layer of the at least two layers of said vertically inhomogeneous semiconductor material, said first fixed negative ion region being under the gate, and said second permanently fixed negative ion region being between the gate and the drain contact, wherein a non-zero density of negative ions is lower in said second permanently fixed negative ion region than a density of negative ions in said first fixed negative ion region.