Effect of Al2O3 Deposition and Subsequent Annealing on Passivation of Defects in Ge-Rich SiGe-on-Insulator

Al2O3 deposition and subsequent post-deposition annealing (Al2O3-PDA) is proposed as an effective method to passivate electrically active defects in Ge-rich SiGe-on-insulator (SGOI) substrates. We found that Al2O3-PDA could not only suppress the surface reaction during Al-PDA, but could also effectively reduce the defect-induced acceptor and hole concentration in Ge-rich SGOI. Al2O3-PDA greatly improves the electrical characteristics of a back-gate metal-oxide-semiconductor field-effect transistor fabricated on Ge-rich SGOI.