A transistor includes a polarization layer above a channel layer including a first III-Nitride (III-N) material, a gate electrode above the polarization layer, a source structure and a drain structure on opposite sides of the gate electrode, where the source structure and a drain structure each include a second III-N material. The transistor further includes a silicide on at least a portion of the source structure or the drain structure. A contact is coupled through the silicide to the source or drain structure.