In this paper, we have investigated bilayer HfN
x gate insulator utilizing ECR plasma sputtering especially for the electrical properties with metallic-phase HfN
0.5 gate electrode which was formed by
in-situ process. After PMA of 500°C/10 min in N
2/4.9%H
2 ambient, the bilayer of HfN
1.3 (1.7 nm)/HfN
1.1 (0.9 nm) gate insulator formed on Si(100) showed the EOT of 0.61 nm, leakage current density (@V
FB −1 V) of 5.5 × 10
−3 A/cm
2 and density of interface states (D
it) of 5.5 × 10
11 cm
−2 eV
−1. The n-MISFET with bilayer HfN
x gate insulator exhibited saturation mobility (μ
sat) of 47 cm
2/(V s), which higher than the device with directly deposited HfN
1.3 gate insulator. HfN
x interfacial layer (IL) with low nitrogen concentration was found to significantly improve the interface properties of HfN
x gate stacks.
View full abstract