Visual observation of decelerated ion beam trajectories by using electronically excited molecular ions (N/sub 2//sup +/ or CO/sup +/) in IBD system

Visible optical emission from electronically excited molecular N/sub 2//sup +/ or CO/sup +/ ions was successfully exploited to investigate focusing properties of ion deceleration lens in our ion beam deposition (IBD) system. Yellow or blue light emission was clearly observed at the exit of the deceleration lens when N/sub 2//sup +/ or CO/sup +/ ions was decelerated from 25 keV down to 10 eV or below. The use of these molecular ions is very useful in designing a deceleration lens not only for IBD systems but also for low energy ion implantation systems for shallow junction formation.