Abstract
A semiconductor device includes a substrate (10), a channel layer (12) disposed on the substrate (10), and a barrier layer (14) disposed on the channel layer (12). The semiconductor device further includes a dielectric layer (16) disposed on the barrier layer (14) and defining a first recess exposing a portion of the barrier layer (14). The semiconductor device further includes a first spacer (18a) disposed within the first recess, wherein the first spacer (18a) comprises a surface (14i) laterally connecting the dielectric layer (16) to the barrier layer (14).