Iron-induced deep-level acceptor center in GaN/AlGaN high electron mobility transistors: Energy level and cross section

Dynamic transconductance dispersion measurements coupled with device physics simulations were used to study the deep level acceptor center in iron-doped AlGaN/GaN high electron mobility transistors (HEMT). From the extracted frequency dependent trap-conductance, an energy level 0.7 eV below the conduction band and a capture cross section of 10−13 cm2 were obtained. The approach presented in this work avoids the non-equilibrium electrical or optical techniques that have been used to date and extracts the device relevant trap characteristics in short channel AlGaN/GaN HEMTs. Quantitative prediction of the trap induced transconductance dispersion in HEMTs is demonstrated.