Growth mechanisms and near-interface structure in relation to orientation of MoS₂ sputtered thin films

Abstract

The growth of sputter-deposited MoS 2 thin films is investigated by high-resolution transmission electron microscopy. Pure high-temperature grown films are compared with H 2 O-contaminated films and amorphous annealed films. In the first case, the films are oriented. They have a first interface layer with crystallites having their (002) planes parallel with the substrate. The subsequent growth leads to the already described lamellar structure, with flakes perpendicular to the substrate. This structure can be explained in terms of a local branching process during crystal growth. The orientation relations between the crystallites in the parallel layer and the lamellae are determined. The local structure at the root of the lamellae, as well as at the interface, is investigated by image calculation. Water contamination in the plasma is shown to result in an amorphization of the interfacial region, followed by lamellar growth. Amorphous films annealed under vacuum do not show a lamellar structure, but have isotropic crystallization. In each of these cases, the mechanism determining the film structure is different.

Synthesizing 2D MoS2 Nanofins on carbon nanospheres as catalyst support for Proton Exchange Membrane Fuel Cells

“…randomly-oriented MoS 2 lamellae with voids in between were fabricated by RF sputtering and the growth mechanism has been extensively discussed16171819202122. First we consider the crystalline structure of MoS 2 : individual MoS 2 layers are stacked in a staggered arrangement along the c-axis with the weak van der Waals interactions between the sheets of sulfide atoms.…”

Strength measurement and rupture mechanisms of a micron thick nanocrystalline MoS2 coating using AFM based micro-bending tests

“…Of particular interest is the synthesis and characterization of MoS2 coatings intended to be used in tribological applications. In literature, significantly different MoS2 coating structures are observed due to wide variances in deposition methods such as direct-current or radio-frequency sputtering, and sputtering parameters such as chamber pressure and voltage [6][7][8]. Even the same deposition parameters have been shown to produce different coating structures during subsequent depositions due to variability in the system, sputtering target, or contaminants in the system [9].…”

Applications of Surface Science to Solid Lubricants

“…Removal of the active sites causes the MoS 2 to adopt a lower free energy orientation with the basal planes oriented parallel to the substrate surface. These effects have been beautifully documented by Moser and Ldvy in TEM studies [19].…”

“…The implications of this "paradox" have been the subject of numerous scientific and practical investigations [8][9][10][11][12], and a reasonable picture of the mechanism by which the material functions is beginning to emerge. It is emphasized that this understanding is forthcoming from the results of surface science studies, both spectroscopic investigations of electronic structure and bo.,ding and microscopic examinations of atomic arrangements, crystal structure, and morphology [13][14][15][16][17][18][19][20][21][22][23][24][25][26]. Some recent theoretical interpretations of the surface science results have also proved extremely valuable [27,28].…”