Trapping properties of LiNbO3/AlGaN/GaN metal-ferroelectric-semiconductor heterostructure characterized by temperature dependent conductance measurements

The trapping properties of the ferroelectric LiNbO3/AlGaN/GaN heterostructure capacitors were characterized by temperature dependent capacitance and conductance measurements. In a wide temperature range (200–450 K), two kind of traps were identified by the conductance measurements. One is the interface trap with the density of 1.1×1012 to 1.4×1010 cm−2 eV−1 which shows an exponential dependency of time constant on the bias applied to the heterostructure. The other is the bulk trap with a lower density, about (1−4)×1010 cm−2 eV−1, which manifests at higher temperatures. The measured time constant of bulk traps (∼1 μs) is almost independent of bias, differing from that of interface traps (about 200 to 1 μs).