A Study of a Single-Wafer Process in Metal Contact Hole Cleaning

摘要

We have implemented our first 300-mm single-wafer metal contact hole clean in order to eliminate a defectivity issue inherent to wet bench cleaning tools. The flow defect issue manifests itself in a characteristic pattern that appears to move defects from the wafer edge to the wafer center. The net effect is damage to the bit line in the form of line thinning, line delamination, and poor gap fill. The single-wafer Spin Processor approach eliminates the flow defect pattern and resolves these damage concerns. Furthermore, it enables a significant reduction in the total number of defects observed and a corresponding increase in die yield without loss of device performance.