Impact of nitrogen post deposition annealing on hafnium zirconate dielectrics for 32 nm high-performance SOI CMOS technologies

The impact of either N2 or N2/O2 Post Deposition Annealing (PDA) and Post Work Function Annealing (PWFA) combinations as well as single N2 or N2/O2 PWFA with different process parameters on HfZrO4 has been investigated in detail for high performance 32 nm SOI CMOS devices. Electrical parameters such as leakage current, capacitance equivalent thickness (CET), threshold voltage and performance as well as reliability data have been taken into account in order to evaluate these treatments. N2/O2 annealing results in severe oxide regrowth due to the presence of oxygen in the annealing ambient. A detailed investigation on the impact of N2 PWFA has been performed.Finally significant gate leakage current benefit, performance and reliability improvements are demonstrated especially for the N2 PWFA treatments in combination with HfZrO4.