The low-frequency noise characteristics of p-type metal-oxide-semiconductor field effect transistors with a strained-Si0.88Ge0.12 channel grown on bulk Si and a PD-SOI substrate

Low-frequency noise properties have been investigated for SiGe p-type metal-oxide- semiconductor field effect transistors with different substrates using Si bulk and a partially depleted silicon-on-insulator (PD SOI). The electrical properties of SiGe PD SOI were enhanced in the subthreshold slope and drain induced barrier lowering. However, the low-frequency noise for the PD SOI was found to degrade significantly in terms of the power spectral density. The low frequency noise was observed to follow the typical 1/fγ(γ = 1) dependence in SiGe bulk devices, but abnormal changes with γ = 2 were revealed in the SiGe PD SOI. The difference of the noise frequency exponent was mainly attributed to generation–recombination by traps presented at the silicon–oxide interface of the SOI. Regardless of the degraded noise performance in the SOI structure, the low-frequency noise level remained well at an acceptable level by virtue of the effective carrier confinement in the SiGe channel.