Study on STI mechanical stress induced variations on advanced CMOSFETs

Impact of shallow trench isolation (STI) induced mechanical stress on MOSFET drive current is investigated by means of a full-matrix active area layout experiment in advanced CMOS process technology. It turns out remarkably that transistor drive current density per unit width is not independent of the active area size, particularly along the direction of the channel current flow. Opposite sensitivities are observed between n- and p-MOSFETs with respect to lateral active area size. The role of gate placement inside the active area is also addressed. A statistical analysis scheme to find principal components is carried out as well.