Tungsten Deposition And Tungsten Etch Residues Improvement

W- CVD has very important application in modern integrated circuit manufacture, and W etchback process used widely in IC filed. In course of integrated circuit manufacture the surface of wafer has still large superficial W residue after W etchback. DRK end point range out of spec during W etchback process. W residue was found via inspection. The issue can affect circuit loss, and result in wafer loss. After investigation, W uniformity NG (LPW depo) was thought the main cause. So challenge was how to ensure stable W uniformity. Via improve setting of W CVD equipment, work method and reasonable distribute of work condition, and condition of W etchback, can effectively improve the phenomena of W residue after W etchback, consequently reduce wafer loss.