A new Inter-electrode coupling capacitance extraction method for deep-submicron AlGaN/GaN HEMTs

Abstract

The accurate extraction of inter-electrode coupling capacitances (IECCs) is a difficult but important issue in small-signal modeling of highly scaled transistors. In this paper, a new method of determining the IECCs for deep-submicron aluminium gallium nitride/gallium nitride (AlGaN/GaN) high electron–mobility transistors (HEMTs) is proposed. The method uses the pinch-off S-parameters under large drain bias to eliminate the influence of intrinsic capacitance on IECCs extraction, thereby determining the reliable starting value of IECCs. Compared with the conventional method, this method not only greatly reduces the parameter searching range in final value optimization but also avoids the non-physical extraction value for intrinsic parameters. Using this method, we build a small-signal model for a 0.15 µm gate-length GaN HEMT. The measured data show that this method has high precision and can be applied to the modeling of millimeter-wave GaN HEMTs.