Study of compositional changes of (Ag-)Sb-S thin films after Ar+ ion laser irradiation by means of micro X-ray fluorescence

Abstract

Thin amorphous films from (Ag-)Sb-S system were prepared as potential candidates for new phase-change memory films. Amorphous (Ag-)Sb-S thin films were deposited by thermal evaporation (TE) of Sb33S67 bulk sample followed by optically induced diffusion and dissolution (OIDD) of thermally evaporated Ag thin films. The phase-change recording process was realized via photocrystallization experiments done by Ar+ ion dot laser exposures of prepared films. Morphology of the laser exposed dots was observed by transmission optical microscopy while micro X-ray diffraction (:-XRD) was utilized for determination of crystallinity of the exposed dots. Laser induced changes were quantified by local measurement of optical transmission in dependence on laser exposure time. Compositional changes are determined via micro-X-Ray Fluorescence (:-XRF). The results prove crystallization of laser exposed thin film. Kinetic of this process is described in terms of transmittance change, evolution of X-Ray diffractograms and changes observable by optical microscopy. Moreover, the results do not indicate any significant chemical change in the case of stoichiometric Sb2S3 after laser irradiation while certain migration of silver takes place in sulfur rich Sb-S films doped by Ag.