Low-Temperature Deuterium Annealing for the Recovery of Ionizing Radiation-Induced Damage in MOSFETs

Ionizing radiation generates bulk traps (N-ot) as well as interface traps (N-it) in the gate dielectric. These traps cause unwanted threshold voltage (V-TH) shifting, subthreshold swing (SS) and increased gate leakage current (IG). In this study, we used low-deuterium annealing (LTDA) as an alternative to conventional annealing, to minimize the side effects of thermal budget. Deuterium atom absorption was confirmed using secondary ion mass spectrometry (SIMS). DC characterizations are performed to analyze the recovery of the gate dielectric damages. Our results demonstrate that the proposed LTDA enables the curing of the gate dielectric damage caused by not only fabrication processing, but also by ionizing radiation. Operating deuterium annealing under low-temperature conditions can improve device performance, reliability, and device-to-device variability.