Trapping properties of LiNbO 3 / AlGaN / GaN metal-ferroelectric-semiconductor heterostructure characterized by temperaturedependent conductance measurements

The trapping properties of the ferroelectric LiNbO 3 / 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 × 10 12 to 1.4 × 10 10 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 ) × 10 10 cm − 2 eV − 1 , which manifests at higher temperatures. The measured time constant of bulk traps ( ∼ 1 μ s ) is almost independent of bias, differing from that of interface traps (about 200 to 1 μ s ).