Comparison of Thermal Stability and Chemical Bonding Configurations of Plasma Oxynitrided Hf and Zr Thin Films

Abstract

In this work, we study the characteristics of plasma oxynitrided Hf and Zr thin films. A 5-nm-thick Hf or Zr metal film is deposited on the bare Si substrate, followed by plasma oxynitridation on these metal films in a or ambient. Incorporation of O and N leads to the formation of and films. The high nitrogen content in the films prepared by plasma oxynitridation is found to increase the onset of the crystallization temperature, as compared to films prepared by plasma oxynitridation. Nevertheless, the difference in crystallization temperature is not seen for films. The interlayer (IL) between (or ) and Si is found to be thinner for the films with plasma oxynitridation than those with plasma oxynitridation. However, the nitrogen incorporated by plasma oxynitridation appears to be depleted after rapid thermal oxidation annealing and is not effective to inhibit the growth of the IL. The activation energy of the IL growth for and oxynitrided is 0.23 and 0.13 eV, respectively. The activation energy of the IL growth for and oxynitrided is 0.19 and 0.14 eV, respectively.