Chemical Mechanical Polishing of Copper in Organic Phosphonic Acid System Slurry

Abstract

Chemical mechanical polishing behavior of copper in organic phosphonic acid system shiny with ammonium persulfate as oxidizer was studied, including the effect of different organic phosphonic acids, concentration of oxidizer and also pH value of slurry. Results showed that there is an optimized concentration value for each kinds of organic phosphonic acid to get maximum material removal rate. With the increasing of pH value, material removal rate also increases, especially when conies into alkaline scope. Shiny with 10mM Dietliylene Triamine Penta Methylene Phosphonic Acid and 3% ammonium persulfate gives the best polishing performance with a too high material removal rate as about 2000 nm/min. With appropriate additives, the material removal rate can be restricted in an acceptable value as below 800 nm/min, and the surface profile is also improved.