Formation of dot patterns with particles using inkjet method to examine and inspect performance of CMP cleaning process

Inkjet technology was applied to develop a standard contaminated wafer for quantitatively and qualitatively evaluating the cleaning efficiency of a post-CMP cleaning process. Aiming at the ultimate goal of forming regular and repetitive dot patterns, each of which consists of one contaminant particle, we controlled the size of micro droplets containing silica particles and ejected from the inkjet head, and the number of particles contained in a droplet. The results of our experiments indicate the feasibility of developing a standard contaminated wafer set as the goal.