Evolution of Raman and photoluminescence response in molybdenum disulfide thin films deposited via thermal atomic layer deposition

In order to enable further advances in microelectronics, new processes capable of precisely depositing films are required. This is especially true of processes meant for depositing two-dimensional (2D) transition metal dichalcogenides, such as MoS2, a material of particular interest due to its high potential mobility even at a thickness of a few atoms. In this work, we report industry-compatible processes for depositing crystalline MoS2 with a high degree of precision. We demonstrate the successful conversion of both MoOx and MoSx films deposited via thermal atomic layer deposition using bis(tert-butylimido)bis(dimethylamino)Mo(VI) and H2O or H2S, respectively, into crystalline MoS2 films after an anneal in H2S. The quality of the MoS2 films was assessed using Raman spectroscopy and photoluminescence (PL) response. We found that the intensity of the obtained PL spectra for MoSx:MoS2 films could be directly controlled as a function of cycle number, demonstrating a precise degree of process control. The physical characteristics of the crystalline MoS2 deposited using this process were further studied using industry-relevant structures, with the process demonstrating conformal MoS2 films deposited evenly throughout lateral trench structures with an aspect ratio of over 20:1. These results provide insight into methodologies for both precisely depositing and rapidly characterizing crystalline MoS2, which can accelerate the integration of 2D materials into leading edge microelectronics.