Applications of PureB and PureGaB ultrashallow junction technologies

A review is given of present and potential applications of pure dopant deposition of boron and gallium integrated as the p⁺-region in p⁺n ultrashallow junctions. Pure B (PureB) layers have been applied in several large area Si diode applications where nm-shallow junctions are required: high-linearity, high-quality varactor diodes for RF adaptive circuits and photodiode detectors for low-penetration-depth beams such as extreme/ vacuum/deep-ultraviolet (EUV, VUV, DUV) light and low-energy electrons. The integration of these types of detectors in CMOS is discussed along with some points that may make the pure dopant depositions attractive for source/drain fabrication in advanced pMOS transistors. Pure Ga capped with pure B (PureGaB) layers have been demonstrated as the p⁺-region in p⁺n Ge-on-Si diodes that are sensitive to infrared wavelengths (> 1 μm) both in avalanche and Geiger mode.