Development of Post-CMP Cleaners for Better Defect Performance

Abstract

In the copper CMP process, organic residues that are related to Benzotriazole (BTA) adsorbed on copper surface after Cu CMP process have to be removed during the cleaning. In order to address this organic defect issue, we present here the study of the performance of BTA removal by post-CMP cleaners using copper particles as substrates instead of copper wafers. In this work, different copper particles including Cu(0), Cu(I) and Cu(II) oxide particles with high surface area, were chosen to study the removal of BTA adsorbed on different copper states. TGA and UV-Vis spectra were used to detect and quantify the BTA removal efficiency. The results by different post CMP cleaners on various Cu particles will be presented.

Role of 1,2,4-Triazole as a Passivating Agent for Cobalt during Post-Chemical Mechanical Planarization Cleaning

“…[5][6][7][8] During the CMP process, organic and inorganic contaminants adsorb onto the Cu and low-k dielectric surfaces and hence a cleaning step, normally referred as the Cu post-CMP cleaning process, is necessary to obtain a defect free surface. 9,10 During the Cu post-CMP cleaning process, the Cu interconnect, the underlying Co barrier material and the adjacent low-k dielectric surfaces are exposed to a cleaning solution containing a plurality of chemical additives like complexing agents, passivating agents, and surfactants. Organic acids such as citric acid, ascorbic acid, gluconic acid, lactic acid and amines such as tetramethyl ammonium hydroxide, monoethanol amine and triethanol amine [11][12][13] are widely used as the complexing agents due to their tendency to form water-soluble complexes with metal ions, copper oxides and hydroxides.…”