Papers by Author: Xiang Feng Chu

Abstract: Ruthenium (Ru) and ruthernium alloys may be utilized as new copper barrier materials in copper interconnects of ultra-large scale integration (ULSI), and chemical mechanical polish (CMP) can be applied in planarization for ULSI production. In this paper, CMP experiments were done on high purity Ru by using home-made slurry, the effect of oxidizer, complexing agent, polishing downforce, pH value, inhibitor species and inhibitor concentration on the material removal rate (MRR) was investigated. The results revealed that MRR can reach 8.7 nm/min under the following conditions: the main constituents in slurry were 1 wt.% SiO2, 1 wt.% (NH4)2S2O8, 1 wt.% tartaric acid and 3 mM imidazole, the pH value was 8.0, the down force was 2.5 psi (17.24 kPa); the roughness Ra was 7.6 nm under these conditions.

Abstract: Osmium (Os) may be used as new barrier material in copper interconnects of ultra-large scale integration. In this work, chemical mechanical polish experiments were done on Os disk using home-made slurry, the effect of pH value, down force, chelating agents, inhibitor species, the concentration of the inhibitor, H2O2 concentration and SiO2 concentration on material removal rate (MRR) was investigated. The results reveal that MRR is 13.1 nm/min when the slurry contains 1wt.% H2O2, 1wt.% SiO2, 1 wt.% citric acid, 1mM BTA and pH =9 and the down force was 1 psi. The influence of the BTA concentration on the corrosion on the surface of Os was analyzed using electrochemical analysis method; it was found that the maximum value of Ecorr appeared when the BTA concentration was 1.5 mm