INFLUENCE OF THE SUBSTRATE DOPING LEVEL ON SPREADING RESISTANCE PROFILING

A study has been performed of spreading resistance probe measurements on a series of 200-nm-deep boron implants into p-type substrates with varying doping levels ranging from 3X10(14) up to 4x10(17)/cm(3). All implants were performed under the same conditions and with the same do se. However, routinely generated spreading resistance carrier profiles from different sites consistently indicate abnormally high doses and shoulder peak artifacts at the back side of the implant profile for th e more highly doped substrates. It is proposed that these artifacts ca n be related to pressure-enhanced carrier spilling effects underneath the probes. When performing a Laplace-based correction and hence negle cting any carrier spilling effects, the correction factor scheme react s upon the position of the on-bevel junction position instead of on th e vertical junction position which can be considerably deeper in the p resence of pressure-enhanced spilling. The observed artifacts can be r educed within Laplace calculations by allowing for more barrier resist ance and consequently a larger contact radius. (C) 1996 American Vacuu m Society.