We report experimental results on the stability of photodiodes obtained at three different wavelengths in the vacuum ultraviolet spectral region. Two of these experiments were based on radiation damage inflicted with excimer lasers at 193 nm and 157 nm and one of them used 135 nm synchrotron radiation. It was found that the detector degradation rate increased considerably with the photon energy and depended on the structure of the photodiodes. Detectors based on the Si/SiO2 interface were damaged much faster than Schottky-type diodes or Si diodes with metal passivating layers. Possible damage mechanisms to the Si/SiO2 interface and its electronic structure are reviewed. In the end a model to quantify the dependence of the damage on the photon energy is introduced.
Citation: Journal of Electron Spectroscopy and Related Phenomena
Pub Type: Journals
detector standards, excimer laser, interface trap states, photolithography, radiation damage, radiometry, synchrotron radiation, UV detector