Aerosol-Assisted Chemical Vapor Deposition of Transition Metal Dichalcogenides

Erik Ferenczy, Ian Germaine, Saleh Muhammed

University of Florida

Tetrakis(dithiocarboxylato)molybdenum(IV) complexes of the type Mo(S2CR)4 (R = Me, Et, iPr, Ph) and molybdenum bis(imido) bis(thiolato) complexes of the type Mo(N^tBu)₂(SR)₂ (R = ^tBu, ⁱPr) were synthesized and evaluated as precursors for aerosol-assisted chemical vapor deposition (AACVD) of MoS₂ and nitrogen-doped MoS₂ thin films. The thermal behavior of the complexes as determined by TGA and GC-MS was appropriate for AACVD, although most of the complexes were not sufficiently volatile for conventional CVD bubbler systems. Thin films of MoS2 were grown by AACVD at 500 °C from solutions of Mo(S2CMe)4 in toluene. The films were characterized by GIXRD diffraction patterns which correspond to a 2H-MoS2 structure in the deposited film. Mo-S bonding in 2H-MoS2 was further confirmed by EDX and XPS which also identified the presence of Mo-N bonding. The film morphology, vertically oriented structure, and thickness (2.54 µm) were evaluated by FE-SEM. The Raman E¹_2g and A_1g vibrational modes of crystalline 2H-MoS₂ were observed. These results demonstrate the use of dithiocarboxylato ligands for the chemical vapor deposition of metal sulfides and imido ligands for nitrogen doping.