A method of forming integrated circuits includes providing a wafer that includes a plurality of dies; aligning a first top die to a first bottom die in the wafer; recording a first destination position of the first top die after the first top die is aligned to the first bottom die; bonding the first top die onto the first bottom die; calculating a second destination position of a second top die using the first destination position; moving the second top die to the second destination position; and bonding the second top die onto a second bottom die without any additional alignment action.