Abstract: A measurement pattern for monitoring overlay shift of bonded wafers includes a top wafer pattern and a bottom wafer pattern. The top wafer pattern includes a first portion with a width Wx1 measured along a first axis. The bottom wafer pattern includes a first part with a width Wx2 measured along the first axis, wherein the first portion of the top wafer pattern and the first part of the bottom wafer pattern are separated by a target distance Dx, and wherein the measurement pattern satisfies the following measurement formulas: Tx>Dx?Sx; Tx<Dx?Sx+Wx2; Tx>Sx; Tx<Dx?Sx+Wx1; wherein, Tx represents a searching distance for finding an end-point of the first portion or an end-point of the first part; and Sx represents an actual shifting amount of the first portion.