SEMICONDUCTOR DEVICE AND MANUFACTURNG METHOD THEREOF

A semiconductor device and a manufacturing method thereof are provided. The semiconductor device includes a substrate, a transistor and a heat dissipation structure. The substrate includes first and second semiconductor layers, and includes an insulating layer disposed between the first and second semiconductor layers. The substrate has a recess extending into the insulating layer from a surface of the first semiconductor layer. The transistor includes a hetero-junction structure, a gate electrode, a drain electrode and a source electrode. The hetero-junction structure is disposed on the second semiconductor layer. The gate, drain and source electrodes are disposed over the hetero-junction structure. The gate electrode is located between the drain electrode and the source electrode, and an active area of the hetero-junction structure located between the drain electrode and the source electrode is overlapped with the recess of the substrate. The heat dissipation structure is disposed on the surface of the firs