Time evolution of ion energy distributions for plasma doping

Plasma doping of semiconductors is being investigated for low-energy ion implantation to form ultra-shallow junctions. Ions are extracted from a quasi-dc plasma using a pulsed bias on the substrate. The shape of the resulting ion energy and angular distribution (IEAD) is particularly important with respect to obtaining desired junction characteristics. Images are presented of the time evolution of the IEAD in a plasma doping system.