Design, fabrication and physical analysis of TiN/AlN deep UV photodiodes

International audienceDeep-ultraviolet solar-blind photodiodes based on high-quality AlN films grown on sapphire substrates with a metal-semiconductor-metal configuration were simulated and fabricated. The Schottky contact is based on TiN metallisation. The material is characterised by micro-Raman spectroscopy and X-ray diffraction technique. The detector presents extremely low dark current of 100fA at -100V DC bias for a device area of 3.1 mm 2. It also exhibits a rejection ratio between 180nm and 300nm of three orders of magnitude with a very sharp cut-off wavelength at 203nm (∼6.1eV). The simulation, based on a 2D energy-balance model using COMSOL® software, permits to help the designer for the optimum topology determination by means of physical studies. The measurement results are in good agreement with the model predictions