A semiconductor structure is provided. The semiconductor structure includes a first semiconductor device. The first semiconductor device includes a first bonding layer formed below a first substrate, a first bonding via formed through the first oxide layer and the first bonding layer, a first dummy pad formed in the first bonding layer. The semiconductor structure includes a second semiconductor device. The second semiconductor device includes a second bonding layer formed over a second substrate, a second bonding via formed through the second bonding layer, and a second dummy pad formed in the second bonding layer. The semiconductor structure includes a bonding structure between the first substrate and the second substrate, wherein the bonding structure includes the first bonding via bonded to the second bonding via and the first dummy pad bonded to the second dummy pad.