Conditions of ion implantation into thin amorphous Si gate layers for suppressing threshold voltage shift

We collected data of ion-implantation profiles using Monte Carlo simulation , and showed that these profiles can readily be expressed by a joined half Gaussian function. We extracted parameters of the joined half Gaussian func tion from the Monte Carlo data. We also derived a model of the shift in thr eshold voltage caused by the penetration of ion-implanted impurities. Based on the set of profile data. we evaluated the ion-implantation conditions f or As, P, B, and BF2 to suppress the threshold voltage shift. (C) 2000 Else vier Science Ltd. All rights reserved.