Precise measurement of the wafer circuit width using computer vision

A method of measuring the two-dimension and nano-width of wafer with fast speed and high precision level of sub-pixel width is offered in this paper. This method takes two steps: Firstly, utilizing the standard ruler to fast measure the pending size with per-pixel level of precision; secondly, utilizing the technology of spatial moment pixel subdivision to precisely locate the edge pixels of pending graph, achieving sub-pixel level of precision. We apply this method to measure and validate one welding-plate among the wafers. The result indicates that the measuring precision has been improved significantly and it can satisfy the requirement of the wafer's CD measurement and calibration.