Threading dislocation induced low frequency noise in strained-Si nMOSFETs

The correlations between the threading dislocations and the low-frequency noise characteristics of the n-type strained-Si field-effect transistors are studied using the devices with different sizes. The device-area-dependent S/sub VG/ (power spectral density of the gate referred voltage noise) ratio of the strained-Si devices over the control Si devices obtained form geometric average can be understood by the modified carrier number fluctuation model with excess traps from the Poisson distributed threading dislocations. The equivalent trap number per threading dislocation extracted from the area-dependent S/sub VG/ ratios is /spl sim/85 for the strained-Si devices, and which results in /spl sim/4.2X degradation of the S/sub VG/ for the strained-Si device with the device area of 625 μm².