Gallium nitride (GaN) based semiconductor devices and methods of manufacturing the same. The GaN-based semiconductor device may include a heterostructure field effect transistor (HFET) or a Schottky diode, arranged on a heat dissipation substrate. The HFET device may include a GaN-based multi-layer having a recess region; a gate arranged in the recess region; and a source and a drain that are arranged on portions of the GaN-based multi-layer at two opposite sides of the gate (or the recess region). The gate, the source, and the drain may be attached to the heat dissipation substrate. The recess region may have a double recess structure. While such a GaN-based semiconductor device is being manufactured, a wafer bonding process and a laser lift-off process may be used.