Authors: A. Pauchard, P.A. Besse and R.S. Popovic
Affilation: EPFL, Switzerland
Pages: 420 - 425
Keywords: avalanche breakdown, field limiting ring, metal field plate, shallow junction, CMOS
Avalanche breakdown often limits the working range of planar junction diodes in electronic circuits and in sensors. We present two-dimensional device simulation results (using MEDICI) of a novel CMOS compatible structure. It combines a floating field limiting ring and a metal field plate in order to enhance the breakdown voltage Vbd of highly-doped shallow planar junctions. Electrical simulations have shown that a single field limiting ring is effective in increasing Vbd only if placed at a distance d smaller than 300nm. For d=lOOnm, breakdown even occurs over the plane diode. At distance d=4OOnm, the field ring can enhance the breakdown voltage only if combined with a metal field plate. Vbd increases linearly with negative applied gate voltage, with a proportionality factor of about 0.1. For a gate voltage of -1OV, Vbd increases by about 12 % up to -12.8 V. Measurements on diodes integrated in standard industrial CMOS 0.5 1lm process corroborate with simulation results.