A process of forming an electronic device can include forming a channel layer overlying a substrate and forming a barrier layer overlying the channel layer. In an embodiment, the process can further include forming a p-type semiconductor layer over the barrier layer, patterning the p-type semiconductor layer to define at least part of a gate electrode of a transistor structure, and forming an access region layer over the barrier layer. In another embodiment, the process can further include forming an etch-stop layer over the barrier layer, forming a sacrificial layer over the etch-stop layer, patterning the etch-stop and sacrificial layers to define a gate region, forming an access region layer over the barrier layer after patterning the etch-stop and sacrificial layers, and forming a p-type semiconductor layer within the gate region.