Properties of Schottky contact in MSM UV detectors based on AlGaN/GaN heterostructure

AlGaN/GaN heterostructure samples are grown on sapphire substrate by metallorganic chemical vapor deposition (MOCVD) method. Ti/Al/Ti/Au and Ni/Au metal films are sputtered on the samples respectively. They are thermally annealed in the N2 gas for different time and temperatures, and become ohmic contact and Schottky contact respectively. Both I-V curves and C-V curves are discussed in term of the measurement results. The I-V curves have very good symmetry, but C-V curves slowly lose their symmetry with the annealing time increasing. Metal-semiconductor-metal photodetector (MSM PD) have good performance on the ultraviolet/visible contrast and selectivity and the photoconductive gain effect is observed in the MSM PD ultraviolet response curves.EI0SUPPL.247-2512