Power switching devices include a semiconductor layer structure that has an active region and an inactive region. The active region includes a plurality of unit cells and the inactive region includes a field insulating layer on the semiconductor layer structure and a gate bond pad on the field insulating layer opposite the semiconductor layer structure. A gate insulating pattern is provided on the semiconductor layer structure between the active region and the field insulating layer, and at least one source/drain contact is provided on the semiconductor layer structure between the gate insulating pattern and the field insulating layer.