High-Efficiency Silicon Photodiode Detector for Sub-keV Electron Microscopy

Self-aligned two-layer metallization with low series resistance for litho-less contacting of large-area photodiodes

“…The diodes were processed in a flow similar to that shown in Fig. 2 but without texturing and with the metal on the light-entrance window removed by dipping in 0.55% HF [14].…”

“…The anode was formed by a pure boron chemical-vapor deposition (CVD) in what is called PureB technology. PureB p + n photodiode detectors have become well established as the devices of choice for detection of low-penetration-depth beams such as vacuum-ultraviolet light (VUV) [13] and low-energy electrons [14] because the photosensitive region can be created in the top few nanometer of the silicon. The fact that the PureB process is highly compatible with CMOS processing has been very important for the realization of high-performance detectors [15] and the present work is also a good example of how integration flexibility is promoted by the chemical and electrical robustness of the PureB layer junction.…”

Conductance Along the Interface Formed by 400 °C Pure Boron Deposition on Silicon

“…These junctions have found application as photodiodes for the detection of vacuum ultraviolet (VUV) light [1] and low energy electrons [2] where the latter application makes use of the fact that a couple of nanometers of the PureB layer itself can form both the anode and a chemically and electrically robust front-entrance window. Recently, similar qualities were also demonstrated for a PureB deposition temperature of 400°C [3].…”

UV-Sensitive Low Dark-Count PureB Single-Photon Avalanche Diode

“…Capping layers such as Al and SiO 2 can be removed selectively from the PureB layer using HF wet etching. With all these properties, it has been possible to integrate detectors that have surpassed the performance of other existing technologies on points such as internal/external quantum efficiency, dark current, and responsivity degradation [8]- [10].…”