A complementary metal-oxide-semiconductor field effect transistor structure includes ion implants in only one of the two complementary devices. The transistor structure generally includes a compound semiconductor substrate and an epitaxial layer structure that includes one or more donor layers that establish a conductivity type for the epitaxial layer structure. The ion implants function to “invert” or “reverse” the conductivity type of the epitaxial layer structure in one of the complementary devices. In the example embodiment, p-type acceptor implants are utilized in the p-channel device, while the n-channel device remains implant-free.