HIGH ELECTRON MOBILITY TRANSISTOR STRUCTURE AND FABRICATION METHOD THEREOF

A high electron mobility transistor structure includes a compound semiconductor channel layer disposed on a substrate, a compound semiconductor barrier layer disposed on the compound semiconductor channel layer, and a compound semiconductor cap layer disposed on the compound semiconductor barrier layer. The compound semiconductor cap layer includes a first segment and a second segment arranged along a first direction, and there is a gap between the first segment and the second segment. A gate electrode is disposed on the compound semiconductor cap layer. A source electrode and a drain electrode are disposed on the compound semiconductor barrier layer, arranged along a second direction and located on two sides of the compound semiconductor cap layer, respectively.