In this report, we investigate the effect of low coefficient of thermal
expansion (CTE) metals on the operating speed of hafnium-based oxide
capacitance. We found that the cooling process of low CTE metals during rapid
thermal annealing (RTA) generates in-plane tensile stresses in the film, This
facilitates an increase in the volume fraction of the o-phase and significantly
improves the domain switching speed. However, no significant benefit was
observed at electric fields less than 1 MV/cm. This is because at low voltage
operation, the defective resistance (dead layer) within the interface prevents
electron migration and the increased RC delay. Minimizing interface defects
will be an important key to extending endurance and retention