Patent ID: 9490356
Filing Date: 2016-11-08
CPC Classification: H01L

Claim Text:
1. A method for forming a passivated AlGaN/GaN HEMT, comprising: forming a GaN buffer/channel layer on a substrate; forming an AlGaN barrier layer on the GaN buffer/channel layer to form an AlGaN/GaN structure; etching mesa isolation trenches in the AlGaN barrier layer to define an area on an upper surface of the barrier layer on which a source, a drain, and a gate element of a HEMT are to be formed; subjecting the AlGaN/GaN structure to an ex situ cleaning to prepare the AlGaN/GaN structure for growth of a III-nitride passivation layer thereon; placing the cleaned AlGaN/GaN structure into an atomic layer epitaxy (ALE) reaction chamber and subjecting the AlGaN/GaN structure to an in situ cleaning to further prepare the AlGaN/GaN structure for growth of the III-nitride passivation layer thereon; growing the III-nitride passivation layer on an upper surface of the AlGaN barrier layer by ALE at a temperature of about 300° C. to about 850° C. to form a passivated AlGaN/GaN structure; etching the III-nitride passivation layer to expose portions of the AlGaN surface for deposition of materials for source, a gate, and a drain electrodes; and forming the source, gate, and drain electrodes on the portions of the AlGaN surface defined by the etched passivation layer.