SIMS/ARXPS—A New Technique of Retained Dopant Dose and Profile Measurement of Ultralow-Energy Doping Processes

A newly developed surface analysis technique, which combines secondary ion mass spectrometry with angle-resolved X-ray photoelectron spectroscopy, was used to achieve more accurate results of the retained impurity doses and profiles for ultralow-energy implants, including conventional beamline implant and plasma immersion ion implantation (PIII). Using this method, it has been found that the B₂H₆ (diborane) PIII demonstrates thicker native oxide and much more B dose loss during rapid thermal processing and surface-cleaning treatments than conventional beamline ion implantation, due to the higher surface B concentration. In order to match the electrical parameters of the device, PIII must consider higher nominal dose to compensate the B loss.