US Patent 11683924 Memory device and manufacturing method

A static random access memory device includes a first gate of a write port circuit disposed in a standard threshold voltage region of a substrate and a second gate of a read port circuit disposed in a low threshold voltage region, abutting the standard threshold voltage region, of the substrate. A distance between a first edge, corresponding to an edge of the first gate, and a boundary, between the standard threshold voltage region and the low threshold voltage region, is different from a distance between the boundary and a second edge, corresponding to an edge of the second gate.