Effect of mechanical process parameters on chemical mechanical polishing of Al thin films

Abstract

The effects of polishing pressure and abrasive on the chemical mechanical polishing of blanket and patternedaluminum thin films were investigated. The CMP process experiments were conducted using a soft pad andslurry mainly composed of acid solution and Al O abrasive. The result of the blanket film showed that, as the23concentration of abrasive in the slurry increased, surface roughness deteriorated but waviness improved. Theplanarity of the patterned Al films was slowly improved by the CMP when the widths of the gaps between thepatterns were relatively small. An attempt was made to find the optimum CMP process conditions by which thepatterned Al thin film could be planarized with a fine surface. The most satisfactory film surface was obtainedwhen the applied pressure was low (10 kPa) and the abrasive concentration was relatively high (5 wt.%). 2003 Elsevier Science B.V. All rights reserved.