Hafnium-nitride gate insulator formed by electron-cyclotron-resonance plasma sputtering

Abstract

We investigated nitrogen-rich HfN insulator on p-Si(100) substrate to prevent to form an interface layer with low dielectric constant by electron-cyclotron-resonance plasma sputtering method for the first time. The nitrogen concentration in the deposited HfN film was confirmed as approximately Hf:N = 1:1.2. Furthermore, the electrical properties of Al/HfN/p-Si(100) gate stack were improved by hydrogen anneal compared to nitrogen (N₂) anneal. The EOT of 0.64nm with low leakage current of 6.2×10^-4 A/cm² (@ V_FB -1V) was obtained. The results suggest that the effect of hydrogen anneal attributed to improve the electrical properties of HfN gate dielectric.