Screened remote plasma-enhanced atomic vapor deposition of Sb-Te thin film for the improvement of trench-covering ability

A new screened remote plasma-enhanced atomic vapor deposition (SPEAVD) technique was studied for depositing Sb-Te phase-change materials inside trench structures with high aspect ratios. The theoretical model of the screening mechanism included the concepts of a plasma sheath and a sticking coefficient. Plasma's limitation of poor step coverage was overcome by filtering its high-energy ions and electrons. Cross-sectional observation was conducted using field emission scanning electron microscopy (SEM). The trench-covering ability of SPEAVD was much better than that of direct remote PEAVD under broad chamber conditions. Surface morphology was observed by SEM and atomic force microscopy. The surface chemical state of the deposited film was measured by X-ray photoelectron spectroscopy. The crystallinity in various deposition temperatures was analyzed by X-ray diffraction measurements. The electrical characteristics of the films were measured by a four-point probe. We expect this research to provide a new deposition method that will allow fine control of step coverage and other characteristics.