Investigation of low frequency noise in uniaxial strained PMOSFETs

We have investigated the low frequency noise characteristics for uniaxial strained PMOSFETs. In the low |V_gst| regime, the 1/f noise is dominated by the carrier-number-fluctuations and the S_Id/_Id ² is increased by the enhanced g_m/I_d for the strained device. Nevertheless, the S_Id/I_d ² of the strained device is almost the same as the unstrained one at a given g_m/I_d. Furthermore, with the application of uniaxial compressive strain, the attenuation length lambda is reduced because of the increased out-on-plane effective mass and tunneling barrier height. The reduced lambda may result in a smaller S_Vg. In the high |V_gst| regime, the 1/f noise is dominated by the mobility-fluctuations and the S_Id/I_d ² is increased due to the larger Hooge parameter for the strained device.