GaN MSM UV photodetectors with titanium tungsten transparent electrodes

GaN metal-semiconductor-metal (MSM) ultraviolet photodetectors with titanium tungsten (TiW) transparent electrodes were fabricated and characterized. It was found that the 10-nm-thick TiW film deposited with a 300-W RF power can still provide a reasonably high transmittance of 75.1% at 300 nm, a low resistivity of 1.7/spl times/10/sup -3/ /spl Omega//spl middot/cm and an effective Schottky barrier height of 0.773 eV on u-GaN. We also achieved a peak responsivity of 0.192 A/W and a quantum efficiency of 66.4% from the GaN ultraviolet MSM photodetector with TiW electrodes. With a 3-V applied bias, it was found that minimum noise equivalent power and maximum D/sup */ of our detector were 1.987/spl times/10/sup -10/ W and 6.365/spl times/10/sup 9/ cmHz/sup 0.5/W/sup -1/, respectively.