The avalanche drift diode-A back illumination drift silicon photomultiplier

Development of high quantum efficiency photon detectors is needed for many low light level (LLL) applications. Recently a new type of photodetector was introduced, the so-called Silicon PhotoMultiplier (SiPM). Its good characteristics (fast response, high gain and single photon resolution capability) make SiPM suitable for many applications. Yet its quantum efficiency is still not satisfactory (< 40%) for LLL applications. A new detector concept is presented that promises very high (> 80%) quantum efficiency in a wide wavelength range (300-1000nm). Combining the drift diode with an avalanche structure placed on the opposite side of the large-area radiation entrance window on the fully depleted bulk, one obtains a large-area device that focuses the photoelectron onto a small point-like avalanche region. Engineering of the shallow radiation entrance window provides high quantum efficiency in the desired wavelength range. Such a device can be used as a building block for a silicon photomultiplier. Extensive simulations have demonstrated the validity of this concept. A production of test devices for the optimization and characterization of avalanche regions and technology parameters has been carried out. The first results from this proof of principle production are presented. (c) 2007 Elsevier B.V. All rights reserved.