EFFECTS OF ARGON ION-BOMBARDMENT ON THE BASAL-PLANE SURFACE OF MOS2

The surface composition and structure of the basal plane surface of MoS//2 was modified by 10-ke V agron ion bombardment and then studied with X-ray photoelectron spectroscopy. The rigid shift of both sulfur and molybdenum core levels is demonstrated to result from the formation of a small amount of Mo islands on the surface, although there is no a priori evidence for changes in oxidation state at the surface after bombardment. This conclusion is suggested by recent data on the deposition of metals on the MoS//2 basal plane that indicate a strong correlation between the Mo or S binding energy and the electronegativity of the metal. Results are compared with those of previous studies and are explained in terms of recent theories on the effects of surface ion bombardment that suggest that chemical/thermal effects dominate over substrate mass effects for higher projectile ion mass and energy.