Effective mobility and interface-state density of La2O3 nMISFETs after post deposition annealing

In this paper, we reported the effective mobility and the interface-state density of La2O3 nMISFETs fabricated under different post deposition annealing (PDA) conditions; annealing temperature (300 ◦C – 600 ◦C) and ambient (N2 or O2). High effective mobility of 312 cm2/Vs and low interface-state density of 6 × 1010 cm−2/eV were obtained from La2O3 nMISFET with equivalent oxide thickness (EOT) of 1.7 nm after PDA at 300 ◦C in N2 ambient for 10 minutes. Gate leakage current density was 6.8 × 10−6A/cm2. We found that peak effective mobility decreased with increasing anneal temperature, regardless of annealing ambient. We also observed a monotonous relationship between effective mobility and interface-state density. This behavior suggests that lowering the interface-state density is essential to obtain high mobility in the high-κ/Si structure.