A New Approach to Enhance the Deuterium Annealing Process for Reliability Improvement in MOS Devices

摘要

It has been widely demonstrated that the hot-carrier lifetime of MOS devices can be significantly improved by a post metallization anneal in deuterium instead of hydrogen [1-5].The improvement has been solely attributed to deuterium passivation of silicon dangling bonds at the gate oxide/silicon interface.In practice,most of the interface traps in MOS devices may have been passivated by hydrogen before the final deuterium annealing process.This is due to the ubiquitous presence of hydrogen in modern CMOS processing technology.Therefore,effective deuteration requires both deuterium diffusion to the oxide/silicon interface and displacement of the previously bonded hydrogen.We have performed a series of experiments which show that the latter process is the rate limiting step.