A semiconductor assembly comprises a first device, a second device, a passivation layer and an interconnect structure. The first device comprises a first top metal layer. The second device comprises a second bottom metal layer. The passivation layer is disposed on the second device. The interconnect structure electrically couples the first device to the second device, wherein the interconnect structure comprises a head member, a first leg and a second leg. The head member is disposed on the passivation layer. The first leg penetrates through the passivation layer and the second device, wherein the first leg connects the head member to the first top metal layer. The second leg penetrates through the passivation layer and extends into the second device to connect the head member to the second bottom metal layer. The first leg and the second leg comprise a top portion, an intermediate portion and a bottom portion.