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.
Journal: TechConnect Briefs
Volume: Technical Proceedings of the 1998 International Conference on Modeling and Simulation of Microsystems
Published: April 6, 1998
Pages: 420 - 425
Industry sector: Sensors, MEMS, Electronics