Surface-Charge-Collection-Enhanced High-Sensitivity High-Stability Silicon Photodiodes for DUV and VUV Spectral Ranges

The electrical and optical performance of silicon pure-boron (Pure-B) diode is investigated in relationship to the thermal processing used after formation of the PureB chemical-vapor-deposition layer that creates otherwise extremely ultrashallow p
⁺
-n junctions. The measured responsivity of PureB diodes is high and stable in the deep ultraviolet (UV) and vacuum UV spectral ranges, covering the spectrum from 220 down to 50 nm. Results are presented, showing that a very high surface charge collection efficiency can be obtained owing to a strong surface electric field resulting from a doping profile that is steep and without roll-off right up to the Si surface.