GR-Noise Characterization of Ge pFinFETs with STI First and STI Last Processes

This letter characterizes the generation-recombination noise of Ge pFinFETs, for three different integration schemes: shallow trench isolation (STI) first strained devices; STI last for relaxed and strained ones. It is shown that many Lorentzians exhibit a VGS-independent and thermally activated characteristic frequency. This points out that the responsible defects are located inside the fin and they are found for all studied process conditions. One type of defect with a time constant value of 10 ms at room temperature is process-independent. Regarding the defects, their activation energies and hole capture cross sections have been extracted for fin widths varying from planar-like devices to narrow ones. It is shown that the STI last strained and relaxed devices yield a surface trap density three orders of magnitude above the typical value obtained for a blanket wafer.