Memory circuit layout method

A method includes placing first and second oxide diffusion (OD) layout patterns in a layout design corresponding to first, second, third, and fourth memory cells of a memory circuit. The first OD layout pattern extends along a first direction and has a first source portion shared between the first and second memory cells, and the second OD layout pattern extends along the first direction and has a second source portion shared between the third and fourth memory cells. The method includes placing a first conductive layout pattern in the layout diagram, the first conductive layout pattern corresponding to a first conductive structure under a lowest via plug layer of the memory circuit, extending along a second direction, and overlapping the first source portion and the second source portion. The method is wholly or partially performed by using a hardware processor.