In one embodiment a method enabling in situ dopant implantation during growth of a III-nitride semiconductor body, comprises establishing a growth environment for the III-nitride semiconductor body in a composite III-nitride chamber having a dopant implanter and a growth chamber, growing the III-nitride semiconductor body in the growth chamber, and implanting the III-nitride semiconductor body in situ in the growth chamber using the dopant implanter. A semiconductor device produced using the disclosed method comprises a III-nitride semiconductor body having a first conductivity type formed over a support substrate, and at least one doped region produced by in situ dopant implantation of the III-nitride semiconductor body during its growth, that at least one doped region having a second conductivity type.