Efficiently improving electro-conductivity and long-term stability of molybdenum nitride thin films using ammonia

Molybdenum nitride (MoN x ) thin films (TFs) have attracted considerable attention for semiconductor and on-chip electronic applications because of their high electrical conductivity, thermal stability, and excellent mechanical properties. In particular, MoN x TFs are widely used as electrode materials and copper diffusion barrier for advanced nano-electronic devices. Thus, in this work, MoN x TFs were fabricated using innovative sequential approach (sputtering + chemical vapor deposition). The structural, chemical, and electrical properties of the MoN x TFs with different thicknesses were systematically investigated. Among the fabricated samples, the D1 device (< 30 nm thickness) exhibited metallic transport behavior with high electrical conductivity of 7.75 Ω -1 cm -1 , ultra-low resistivity of 12 μΩ.cm, work function of 4.68 eV, and Hall mobility (∼ 33 cm 2 V -1 s -1 ). Furthermore, the fabricated MoN x TFs demonstrated excellent thermal and oxidation stability, maintaining stable electrical characteristics up to 120 °C and after two month of air exposure. In addition to the experimental characterizations, density functional theory (DFT) calculation were performed to further understand the electrical performance of MoN x TFs, vacancy defects, and density of states of the MoN x TFs. These findings provide the potential of MoN x TFs that can be utilized as next-generation for advanced electronic and memory device applications.