Schottky diodes fabricated on cracked GaN epitaxial layer grown on (111) silicon

Abstract

The planar Schottky diodes were fabricated, characterized and modelled to study the electrical characteristics of cracked GaN epitaxial layer on (111) silicon substrate. We deposited Ti/Al/Ni/Au as the ohmic metal and Pt as the Schottky metal. The ohmic contact resistivity was 5.51×10-5 Ω·cm2 after annealing in N2 ambient at 700°C for 30 s. The fabricated Schottky diode exhibited the barrier height of 0.7 eV and the ideal factor was 2.4. We got the cutoff wavelength at 360 nm, peak responsivity of 0.097 A/W at 300nm, and UV/visible rejection ratio was about 104. The SPICE simulation with the circuit model, which was composed with one Pt/GaN diode and three parasitic diodes, showed good agreement with the experiment. © 2005 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.