A semiconductor structure and method for manufacturing thereof are provided. The semiconductor structure includes a silicon substrate having a first surface, a III-V layer on the first surface of the silicon substrate and over a first active region, and an isolation region in a portion of the III-V layer extended beyond the first active region. The first active region is in proximal to the first surface. The method includes the following operations. A silicon substrate having a first device region and a second device region is provided, a first active region is defined in the first device region, a III-V layer is formed on the silicon substrate, an isolation region is defined across a material interface in the III-V layer by an implantation operation, and an interconnect penetrating through the isolation region is formed.