Surface depletion region width dependence of threshold voltage shift of ionhyphen;implanted MOS transistor

摘要

Even under the same implantation conditions, e.g., 50hyphen;keV11Bplus;ions implanted through 1100hyphen;Aring; gate oxides on 4hyphen;OHgr; cm silicon substrates, the threshold voltage shift ofnhyphen;channel MOS transistors is sim;55percnt; of the shift ofphyphen;channel specimens, and deviation from linear dose dependence is observed for thenchannel above a dose of 6times;1011sol;cm2, while for aphyphen;channel case the threshold voltage shift depends linearly on the net dose in silicon at least up to 1times;1012sol;cm2. These results are discussed and explained with a calculated dose dependence that accounts for the large decrease of the maximum width of the depletion layer with increasing dose for acceptorhyphen;implantednhyphen;channel specimens.