Study on E-CMP of Cu and its mechanism

Low-k material in Cu/Low-k wiring in the next generation LSI becomes weak, which requires low pressure processing. In this study, we paid attention to the electrolysis chemical mechanical polishing (E-CMP) that is expected to provide high efficient polishing in low-pressure range. The experiment result has clarified that the voltage and current density have a substantial effect on the processing rate. It was also known that addition of BTA to slurry is effective in improving surface roughness. In like wise, addition of abrasives is effective in increasing processing rate and improving surface roughness. The experiment has clarified basic processing characteristics and processing mechanism, which will serve as a guideline for E-CMP