Comprehensive Study on Trap-Induced Bias Instability via High-Pressure D₂ and N₂ Annealing

Forming gas annealing (FGA) in a deuterium (D-2) ambient is crucial importance to MOSFET fabrication technologies related to alleviation of trap state at Si/SiO2 interface as well as oxide bulk by D-2 passivation. In this study, post metal annealing (PMA) process with D(2 )and N-2 gases under a high-pressure condition was conducted to verify performance enhancement in gate-enclosed FETs. We explored the trap behaviors inside the bandgap of Si and SiO2 by quantitatively using capacitance-voltage (C-V) characteristics. Furthermore, the change of deuterium and nitrogen ions in Si/SiO2 gate stack before and after the PMA process was directly investigated by time-of-flight secondary ion mass spectroscopy (ToF-SIMS) depthprofiling technique.