Methods relating to a group III HFET with a graded barrier layer

摘要

A device and a method of making said wherein the device wherein the device has a group III-nitride buffer deposited on a substrate; and a group III-nitride heterostructure disposed on a surface of the group III-nitride buffer, wherein the group III-nitride heterostructure has a group III-nitride channel and a group III-nitride barrier layer disposed on a surface of the group III-nitride channel, the group III-nitride barrier layer including Al as one of its constituent group III elements, the Al having a mole fraction which varies at least throughout a portion of said group III-nitride barrier layer.

主权项

1. A method of making a device, comprising:
forming a III-nitride buffer on a substrate; and forming a III-nitride heterostructure disposed on a surface of the III-nitride buffer, wherein the III-nitride heterostructure has a III-nitride channel and a III-nitride barrier layer disposed on a surface of the III-nitride channel, the barrier layer including Al as one of its constituent elements, the Al having a mole fraction which (i) remains essentially constant throughout a first portion of said group III-nitride barrier layer and (ii) varies at least throughout a second portion of said group III-nitride barrier layer; wherein the second portion of the III-nitride barrier layer comprises a AlGaN layer which varies from approximately Al0.25Ga0.75N to approximately Al0.35Ga0.65N with the higher Al mole fraction occurring at said surface of said barrier layer remote from the III-nitride channel.