A semiconductor device comprises: a substrate; a multi-layer semiconductor layer located on the substrate, the multi-layer semiconductor layer being divided into an active area and a passive area outside the active area; a gate electrode, a source electrode and a drain electrode all located on the multi-layer semiconductor layer and within the active area; and a heat dissipation layer covering at least one portion of the active area and containing a heat dissipation material. In embodiments of the present invention, a heat dissipation layer covering at least one portion of the active area is provided in the semiconductor device. The arrangement of the heat dissipation layer adds a heat dissipation approach for the semiconductor device in the planar direction, thus the heat dissipation effect of the semiconductor device is improved.