Patent ID: 6548333
Filing Date: 2003-04-15
Classification: H01L

Abstract:
A high electron mobility transistor (HEMT) comprising:a gallium nitride (GaN) channel layer; an aluminum gallium nitride (AlGaN) barrier layer on the channel layer; a first ohmic contact on the barrier layer to provide a source electrode; a second ohmic contact on the barrier layer and spaced apart from the source electrode to provide a drain electrode; a GaN-based cap segment on the barrier layer between the source electrode and the drain electrode, the GaN-based cap segment having a lower concentration of aluminum than the barrier layer and having a first sidewall adjacent and spaced apart from the source electrode; and a non-ohmic contact on the GaN cap segment to provide a gate contact, the gate contact having a first sidewall which is substantially aligned with the first sidewall of the GaN cap segment and the gate contact extending only a portion of a distance between the first sidewall and the second sidewall of the GaN cap segment.