In-line, real-time nondestructive monitoring of Fe contamination for statistical process control (SPC) by surface photovoltage (SPV)

Abstract

During high temperature operations, heavy metals will precipitate and form localized silicides at the silicon/oxide interface, which introduces weak spots that cause gate dielectric integrity and reliability problems. To address this issue real-time monitors of metallic concentration can be used to control contamination to an acceptable level. The technique of surface photovoltage (SPV) is a passive diagnostic which has been implemented into semiconductor manufacturing for this specific purpose. The application of SPV to actual cases in fabrication using SPC is discussed. This emphasizes the need to increase production control of overall metallic contamination for future CMOS technologies which is illustrated.<>