A semiconductor structure includes a first substrate, a metallic pad disposed over the first substrate, a dielectric structure disposed over the first substrate and exposing a portion of the metallic pad, a bonding structure disposed over and electrically connected to the metallic pad, a barrier ring surrounding the bonding structure, and a through-hole penetrating the first substrate and the dielectric structure. The bonding structure includes a bottom and a sidewall, the bottom of the bonding structure is in contact with the metallic pad, a first portion of the sidewall of the bonding structure is in contact with the dielectric structure, and a second portion of the sidewall of the bonding structure is in contact with the barrier ring.