Abstract
In this paper, we have investigated bilayer HfN gate insulator utilizing ECR plasma sputtering especially for the electrical properties with metallic-phase HfN0.5 gate electrode which was formed by in-situ process. After PMA of 500°C/10 min in N2/4.9%H2 ambient, the bilayer of HfN1.3 (1.7 nm)/HfN1.1 (0.9 nm) gate insulator formed on Si(100) showed the EOT of 0.61 nm, leakage current density (@VFB -1V) of 5.5x10-3 A/cm2 and density of interface states (Dit) of 5.5x1011 cm-2eV-1. The n-MISFET with bilayer HfN gate insulator exhibited saturation mobility (μsat) of 47 cm2/(V s), which was higher than the device with direct deposited HfN1.3 gate insulator. HfN interfacial layer (IL) with low nitrogen concentration was found to significantly improve the interface properties of HfNx gate stacks.
