RF noise in 0.18-mu m and 0.13-mu m MOSFETs

Abstract

We have studied the gate finger number and gate ength dependence on minimum noise figure (NFmin) in deep submicrometer MOSFETs. A lowest NFmin. of 0.93 dB is measured in 0.18-mum MOSFET at 5.8 GHz as increasing finger number to 50 fingers, but increases abnormally when above 50. The scaling gate length to 0.13 mum shows larger NFmin than the 0.18-mum case at the same finger number. From the analysis of a well-calibrated device model, the abnormal finger number dependence is due to the combined effect of reducing gate resistance and increasing substrate loss as increasing finger number. The scaling to 0.13-mum MOSFET gives higher NFmin due to the higher gate resistance and a modified T-gate structure proposed to optimize the NFmin for further scaling down of the MOSFET.