Metal-semiconductor-metal photodiodes fabricated from thin-film diamond

A metal-semiconductor-metal Schottky barrier photodetector has been fabricated on a "hydrogen-doped'' surface-conducting chemical vapor deposition (CVD) diamond. The device is fabricated in one step by forming two back-to-back aluminum Schottky diodes on the p-type surface. This simple process is compatible with previously reported metal-semiconductor field-effect transistor fabrication on this type of CVD diamond and offers the prospect of the monolithic integration of a ultraviolet detector and active circuitry. Preliminary electrical and optical characteristics of the device have been measured, including the spectral response over the range 180-800 nm. The device exhibits a linear response with the applied optical power at 220 nm, operates at a bias of only 2 V, and shows visible blind characteristics, with a spectral discrimination of three orders of magnitude as determined from the ratio of 200-550 nm responses. (C) 1999 American Institute of Physics. [S0003-6951(99)01922-1].