DEEP SUB-MICRON SCALE STI CMP PLANARITY ANALYSIS

摘要

Measurements of nitride, trench oxide and step height at the large-size features (at the order of 10 ～ 100 μm) have been used for the STI CMP planarity assessment and process monitoring in the industry. However, it is difficult to use those data to predict the post-CMP status of the deep sub-micron STI structures in the real chip. In this paper, efforts has been contributed to study the STI CMP planarity behaviors with the feature sizes at the deep sub-micron scale, and the correlation between the measurements of large features and deep sub-micron STI structures. Conventional silica based slurry, high selectivity ceria based slurry, and fixed abrasive processes are included in this study.