Series resistance and mobility degradation factor in C-incorporated SiGe heterostructure p-type metal-oxide semiconductor field-effect transistors

We have fabricated p-type metal-oxide semiconductor field-effect transistor (p-MOSFET) devices with channel lengths from 0.8-10 μm on strained Si/Si_0.8Ge_0.2/Si and partially strain compensated Si/Si_0.793Ge_0.2C_0.007/Si heterolayers. The device characteristics, the source-drain resistance and the mobility degradation factor have been studied for control-Si, Si_0.8Ge_0.2 and Si_0.793Ge_0.2C_0.007 devices over the temperature range of 300-77 K. Though a significant improvement in the drive current of Si_0.793Ge_0.2C_0.007 devices has been observed compared to the control-Si and Si_0.8Ge_0.2 devices at room temperature, the performance of ternary devices at 77 K has been found to be inferior to that of binary devices. This has been found to be due to the higher source-drain resistance and mobility degradation factor of Si_0.793Ge_0.2C_0.007 MOSFET devices at cryogenic temperature.