Comparison of Different Ways of Extra Phosphorus Implantation Which Decrease the Threshold Voltage and On-resistance of UMOS

摘要

A method to decrease the threshold voltage andon-resistance is discussed in this paper, which is adding extraphosphorus implantation into silicon. There are two ways toimplant extra phosphorus without adding a mask. The first wayis to implant extra phosphorus after the field oxide etching,and the second way is to implant extra phosphorus with thesource region mask before the N+ implantation. Compare theresults of the two ways to find their characteristics and choosethe appropriate one.