Abstract: A semiconductor structure is provided. The semiconductor structure includes a substrate, a channel layer, a barrier layer, a compound semiconductor layer, a gate electrode, and a stack of dielectric layers. The channel layer is disposed on the substrate. The barrier layer is disposed on the channel layer. The compound semiconductor layer is disposed on the barrier layer. The gate electrode is disposed on the compound semiconductor layer. The stack of dielectric layers is disposed on the gate electrode. The stack of dielectric layers includes layers having different etching rates.

Abstract: A die bonding apparatus comprising a tape transfer device and a bonding device is provided. The tape transfer device includes a roller tape and a first roller axle. The roller tape comprises a plurality of glue layers and a first releasing film. Both surfaces of the glue layers are adhesive. The first releasing film covers one of the surfaces of the glue layers. The first roller axle is used for rolling up the first releasing film so as to rotate the roller tape. The bonding device is disposed at the front end of the tape transfer device. The bonding device includes at least a robotic arm and a controller. The controller controls the rotation and movement of the robotic arm.