Device Wafer의 평탄화와 AFM에 의한 평가

Chemical mechanical polishing (CMP) has become widely accepted for the planarization of multi-interconnect structures in semiconductor manufacturing. However, perfect planarization is not so easily achieved because it depends on the pattern sensitivity, the large number of controllable process parameters, and the absence of a reliable process model, etc. In this paper, we realized the planarization of deposited oxide layers followed by metal (W) polishing as a replacement for tungsten etchback process for via formation. Atomic force microscope (AFM) is used for the evaluation of pattern topography during CMP. As a result, AFM evaluation is very attractive compared to conventional methods for the measurement of planarity. Moreover, it will contribute to analyze planarization characteristics and establish CMP model.