Low temperature analysis of 0.25 μm T-gate strained Si/Si0.55Ge0.45 N-MODFET's

A low temperature de and HF investigation of 0.25 mu m T-gate Si/Si0.55Ge0.45 n-MODFET's is presented. Outstanding maximum oscillation frequencies f(max) range from 100-120 GHz at 300 K up to 195 GHz at 50 K. These high-frequency characteristics are the first reported at low temperature on Si/SiGe n-MODFET's and are also the highest room temperature data reported so far. Physical modeling is used to explain the main trends observed when cooling down the n-MODFET. Many experimental data are presented, The dependence on temperature and biases of the important small-signal equivalent circuit parameters is investigated to analyze the device high-frequency performances and the minimum noise figure of the intrinsic device is determined.