A novel approach for scratch detection and study on dependency of scratches during oxide CMP

Abstract

Oxide CMP process has been well accepted for the planarization of the dielectric oxide film and becomes a critical process in ULSI manufacturing due to the rapid shrinkage of the design rule for the device [1]. But CMP process generates defects inevitably such as micro-scratch, pit, and polishing residue. As the design rule becomes smaller and smaller, the formation of micro-scratches cause severe circuit failure, the reduction of durability and reliability and also the increase of current leakage in semiconductor [2]. It is important to develop post CMP cleaning process to have effective detection of scratches since they are not easy to detect on flat and broad oxide surfaces [3]. In this study, a new method was proposed to detect the scratches and also the dependency of these scratches on process parameters such as pressure, slurry concentration and type of conditioner was examined.