Investigation of low frequency noise in uniaxial strained PMOSFETs

We have investigated the low frequency noise characteristics for uniaxial strained PMOSFETs. In the low |Vgst| regime, the 1/f noise is dominated by the carrier-number-fluctuations and the SId/Id² is increased by the enhanced gm/Id for the strained device. Nevertheless, the SId/I}d² of the strained device is almost the same as the unstrained one at a given gm/Id. Furthermore, with the application of uniaxial compressive strain, the attenuation length λ is reduced because of the increased out-on-plane effective mass and tunneling barrier height. The reduced λ may result in a smaller SVg. In the high |Vgst| regime, the 1/f noise is dominated by the mobility-fluctuations and the SId/Id² is increased due to the larger Hooge parameter for the strained device.