A semiconductor structure includes a substrate, a first polysilicon (polysilicon) region, a second polysilicon region, an insulating layer and a third polysilicon region. The first and second polysilicon regions are formed on the substrate and spaced apart by a gap. The insulating layer formed on the substrate covers the first and second polysilicon regions. The third polysilicon region is formed on the insulating layer and disposed above the gap. When the semiconductor structure is applied to a display panel, a grain boundary of the third polysilicon region in a displaying region and a channel of an active layer intersect at an angle, and the grain boundary of the third polysilicon region in a circuit driving region is substantially parallel to the channel of the active layer.