A novel methodology using pulsed-IV for interface or border traps characterization on AlGaN/GaN MOSHFETs

Characterization of traps at a dielectric/AlGaN interface is critical to evaluate the reliability of the dielectric for the gate stack or passivation of an AlGaN/GaN based MOS Heterojunction Field Effect Transistor (MOSHFET). In this work, we propose a new methodology for interface and border traps characterization using simple DC IV, CV and pulsed-IV measurements. Along with a generic UV lamp, we use this technique to characterize both shallow and deep trap concentrations across the entire AlGaN band gap. The resulting analysis of the ALD HfAlO/AlGaN interface reveals a high density of shallow traps (~7×10¹³ cm^-2.eV^-1) and deep traps (10¹¹-10¹² cm^-2.eV^-1) with a characteristic U-shape.