Discharge of P²⁺ ions in the beamline of medium current implanters

Abstract

The P2+ ion beam has been analyzed behind the beam-filter at the target area of medium current implanters. It has been found that a discharge of P2+ ions occurs with varying setup conditions of the ion beam. Depending on the source pressure, almost any fraction of the P2+ ions is discharged before reaching the target even with the beam filter in the "on" position. The dose monitor is not able to handle an unknown mixture of P2+ and P+ ions so that the implanted doses are higher than anticipated. The influence of the discharge phenomena on a P2+ implanted N-well process will be shown. © 1987.