A new technique to quantify deuterium passivation of interface traps in MOS devices

The ubiquitous presence of hydrogen in the fabrication of complementary metal oxide semiconductor (CMOS) devices results in the passivation of most interface traps by hydrogen. In this letter, we show that this hydrogen cannot be completely replaced by deuterium through a one-step deuterium anneal process. Improved device reliability attributed to deuterium incorporation at the oxide/silicon interface is thus limited by the remnant hydrogen. To determine the deuterium passivation fraction, we propose a new technique that is based solely on electrical testing. Compared to other techniques such as secondary ion mass spectrum (SIMS), the new technique can be used to measure the deuterium passivation fraction in deep submicron MOS devices with very small testing areas.