Study of passivation defects by electroluminescence in AlGaN/GaN HEMTS on SiC

This paper presents a new method of passivation control by electroluminescence (EL) in 0.15 μm AlGaN/GaN HEMT. The electroluminescence signature in one finger HEMTs (W = 1 × 100 μm), and eight fingers ones (W = 8 × 125 μm), is modified by defects located at the passivation/semiconductor interface and is characterized by a light emission along the drain contact. This abnormal emission reveals some modification of the electric field distribution in the gate-drain space probably induced by traps located at the passivation/semiconductor interface. These traps contribute to the creation of a virtual gate in the gate-drain space.