Add one process step to control the SI distribution of Alsicu to improve metal residue process window

摘要

A new method of metal deposition with reduced metal residue after metal etching by cooling the wafer before metal deposition is described. A first patterned conducting layer is provided overlying a dielectric layer on the surface of a semiconductor substrate. The wafer is cooled to a temperature of less than about 20 DEG C. Thereafter, a metal layer is deposited overlying the first patterned conducting layer. The metal layer is etched away where it is not covered by a mask to complete formation of the metal line. Cooling of the wafer before metal deposition decreases the metal residue found after metal etching.