Atomic layer deposition of MoNx thin films using a newly synthesized liquid Mo precursor

Abstract

Molybdenum nitride thin films are deposited using a newly synthesized liquid Mo precursor [MoCl4(THD)(THF)] in an ALD super-cycle process. The new precursor is synthesized using MoCl5 and 2,2,6,6-tetramethyl-3,5-heptanedione, which is a bidentate ligand. The synthesized precursor exists in the liquid phase at room temperature and has a characteristic of evaporating 99% at 150–220 °C. Using this new precursor in an ALD super-cycle process results in a pure MoNx thin film with few impurities (C and O). In addition, such MoNx thin films have relatively low resistivity values due to excellent crystallinity and a low impurity concentration. The films' diffusion barrier characteristics confirm that they can perform the role of a barrier at over 600 °C.