Atomic layer deposition (ALD) has long been developed for conformal coating thin films on planar surfaces and complex structured substrates based on its unique sequential process and self-limiting surface chemistry. In general, the coated thin films can be dielectrics, semiconductors, conductors, metals, etc., while the targeted surface can vary from those of particles, wires, to deep pores, through holes, and so on. The ALD coating technique, itself, was developed from gas-phase chemical vapor deposition, but now it has been extended even to liquid phase coating/growth. Because the thickness of ALD growth is controlled in atomic level ([Formula: see text]0.1[Formula: see text]nm), it has recently been employed for producing two-dimensional (2D) materials, typically semiconducting nanosheets of transition metal dichalcogenides (TMDCs). In this paper, we briefly introduce recent progress in ALD of multifunctional oxides and 2D TMDCs with the focus being placed on suitable ALD precursors and their ALD processes (for both binary compounds and ternary alloys), highlighting the remaining challenges and promising potentials.
TEM investigation of MoSeC films
