Study of the Mechanical Stress Impact on Silicide Contact Resistance by 4-Point Bending

In this work, externally applied mechanical stress impact on silicide contact resistance is studied by in-situ probing in four-point bending (4pb)of a circular transmission line model (CTLM)test structure. Much less stress impact on silicide contact resistance is found compared to the stress impact on n-Si mobility. Stress impact on two silicide contacts (Ti/n-Si and La/n-Si)is studied and different behavior is observed due to the Schottky barrier difference. To explain the phenomenon, a TCAD model of CTLM is implemented and compared with the silicide diode measurement. The shifts of band energy level contribute to the change of Schottky barrier height and hence induce the contact resistance variation.