Wafer testing and self-calibration system

摘要: A measurement station which rotates a wafer in vertical plane and moves scanning sensor linearly along an axis is parallel to the rotation plane, thus providing spiral, or other, scan path across wafer. The orientation reduces errors from weight induced sagging, especially of large, e.g. 300 mm wafers. includes grippers move wafer's for securing position rotation. also master calibration gauges simplify obviate need test technique reducing vibration assuring repeatability coasting coordinated linear probe motions scanning. Probe data obtained digitized early calibration, demodulation, filtering other processing done digitally.