We report the low-frequency noise characteristics of ultrathin body (UTB) p-channel MOSFETs with molybdenum (Mo) as the gate material. Using the number fluctuation model with correlated mobility fluctuation, the dependence of the noise behavior on bias condition is explained. The impact of nitrogen implantation (for gate work function engineering) on the noise behavior is also presented. An exponential increase in noise with nitrogen implant dose is attributed to interface-trap generation caused by nitrogen penetration through the gate oxide.