Photon-enhanced secondary electron emission at target in plasma immersion ion implantation

This paper describes effects of vacuum ultraviolet (VUV) optical emission from the plasma on the secondary electron emission coefficient (SEEC) in PIII processes. To examine this, time-resolved measurements of the VUV emission intensity and the SEEC are performed in continuous and square-wave-modulated discharges. For all the measured data, a good linearity between the SEEC and the VUV intensity is found out, and the ion-induced SEEC can be distinguished from the photon-induced SEEC. In the afterglow of the modulated discharge, the SEEC decreases because the VUV emission intensity. Therefore, ion implantation in the afterglow allows us to reduce a current requirement of the pulse generator, leading to low-cost PIII processes. [Copyright &y& Elsevier]