The Impact of Pre/Post-metal Deposition Annealing on Negative-Bias-Temperature Instability in HfO2 Stack p-Channel Metal-Oxide-Semiconductor Field Effect Transistors

Abstract

This study investigates the impact of pre/post-metal deposition annealing on negative-bias-temperature instability (NBTI) in HfO2 stack p-channel metal-oxide-semiconductor field effect transistors (MOSFETs). In the initial electrical characteristics, the most apparent difference is threshold voltage (V-th) resulting from the work-function difference between the gate material and the semiconductor. Furthermore, fast I-V measurements indicate that the device with post-metal deposition annealing shows more degradation of V-th in NBTI, which originates from the more nitrogen interstitial defects in HfO2. This phenomenon is confirmed to be due to the process-related pre-existing defects by an analysis of double sweep fast I-V measurements. (c) 2015 The Electrochemical Society. All rights reserved.