Effects of High‐Pressure H2 and D2 Post‐Metallization Annealing on the Electrical Properties of HfO2/Si0.7Ge0.3

• Published in: Physica status solidi. PSS-RRL. Rapid research letters Vol. 17; no. 4
• Main Authors: Kim, Jinyong, Choi, Seongheum, Nguyen, An Hoang-Thuy, Lee, Woohui, Choi, Rino, Kim, Hyoungsub
• Format: Journal Article
• Language: English
• Published: Weinheim Wiley Subscription Services, Inc 01-04-2023
• Subjects: Annealing; Deuterium; Electrical properties; Hafnium oxide; HfO2; high-pressure annealing; hydrogen; Leakage current; Metallizing; Passivity; Pressure effects; Si1−xGex; Temperature dependence
• ISSN: 1862-6254; 1862-6270
• DOI: 10.1002/pssr.202200439

High‐pressure annealing (HPA) in both hydrogen (H2) and deuterium (D2) environments is attempted on HfO2/Si0.7Ge0.3 capacitors as a post‐metallization annealing (PMA) approach. As compared with conventional forming gas annealing (FGA), a dramatic reduction in the interface state density (Dit) is achieved after both H2‐ and D2‐HPA processes at the equivalent temperature (300 °C) and time (30 min) by effectively passivating the Ge‐induced dangling bonds at the interface region. Meanwhile, the stress‐induced leakage current characteristics are only improved by the D2‐HPA process, indicating that D‐passivation is more resistant to external electrical stress than H‐passivation. As the PMA temperature increases to 500 °C, both HPA further decreases the Dit, but a significant increase is observed for FGA. In addition, the PMA temperature‐dependent degradation of leakage current is less in HPA than in FGA.
HfO2/Si0.7Ge0.3 capacitors are annealed in H2 and D2 at high pressures (30 bar), and their electrical characteristics as a function of the annealing temperature (300–500 °C) are compared with the samples annealed in forming gas. The changes in the electrical characteristics, such as the interface state density and leakage current, with increasing annealing temperature, are systematically compared between the samples.