Optical stability investigation of high-performance silicon-based VUV photodiodes

Silicon p⁺n photodiodes fabricated by a pure boron deposition technology are evaluated for detection in the Vacuum Ultra-Violet (VUV) spectral range from 115 nm to 215 nm wavelengths, where the attenuation length in silicon is only a few nanometers. It is demonstrated that the junctions formed by the B-layer process are so ultrashallow that the photodiodes are able to provide a very good sensitivity, in the order of 0.1 A/W, in the whole VUV range. Moreover, the demonstrated stability also appears to be very good if isolating layers on the diode surface are avoided.