In an embodiment, a Group III nitride device includes a multilayer Group III nitride structure and a first ohmic contact arranged on and forming an ohmic contact to the multilayer Group III nitride device structure. The first ohmic contact includes a base portion having a conductive surface, the conductive surface including a peripheral portion and a central portion, the peripheral portion and the central portion being substantially coplanar and being of differing composition, a conductive via positioned on the central portion of the conductive surface and a contact pad positioned on the conductive via.