A semiconductor structure includes a first substrate including a cavity extended into the first substrate, a device disposed within the cavity, a first dielectric layer disposed over the first substrate and a first conductive structure surrounded by the first dielectric layer, and a second substrate including a second dielectric layer disposed over the second substrate and a second conductive structure surrounded by the second dielectric layer, wherein the first conductive structure is bonded with the second conductive structure and the first dielectric layer is bonded with the second dielectric layer to seal the cavity.