Front-side and back-side secondary ion mass spectrometry analyses on advanced doping processes for ultra-large scale integrated circuit: A case study

Abstract

The issues caused by the artifacts of sputtering/re-deposition and ion knock-in effects of the conventional front-side secondary ion mass spectrometry (SIMS) measurement are extensively investigated. Back-side SIMS measurement is used to confirm these hypotheses and resolve these issues. Based on back-side SIMS data, plasma immersion ion implantation (PIII) processed wafers show superior junction characteristics and less damages than beamline (BL)-based implant processed wafers, including shallower junction depth (58.9 nm vs. 64.2 nm), similar junction abruptness (9.0 nm/dec vs. 8.7 nm/dec), and less end-of-range defects. They are opposite to the misleading conclusions that front-side SIMS data provided. A better electrical performance by PIII processed device than that by BL-based implant processed device is demonstrated.