Optimization of post polish procedure with respect to defect density reduction in oxide CMP processes

Inhalt:
Reduction of defect density is a major issue in semiconductor industry in general. One of the areas with particular focus on defect density is CMP. Here we describe 4 approaches which resulted in a drastic reduction of defect dens ity post oxide CMP processes. (i.) The first attempt was the increase of table and carrier speed in a DI-water step post the main polish segment. (ii.) In a second iteration different parameter settings for the final polish segment were evaluated. (iii.) In a third test series polish with slurry in the final polish was investigated. The main purpose for that was to reduce the micro-scratch level. (iv.) In an attempt to further reduce slurry residues besides the scratch topic, different water polish times post slurry polish in the final polish segment were investigated. Results of all four attempts are discussed and summarized in this presentation. The overall potential of defect density reduction when all four options are combined is up to >90%.