Defect density reduction in tungsten deposition and etchback

An in-line defect density monitor was developed to measure the defect contribution for tungsten deposition and etchback. By continuously monitoring the processes, a number of defect generating mechanisms were discovered in both deposition and etch systems. By targeting improvements in equipment, processes, and maintenance, a factor of ten improvement was realized on the integrated monitor. The improvements also resulted in improved product yield and eliminated low yield excursions