Rigaku Corporation Wafer Surface Contamination Metrology with TXRF/VPD TXRF-V310

TXRF analysis can gauge contamination in all fab processes, including cleaning, litho, etch, ashing, films, etc. The TXRF-V310 can measure elements from Na through U with a single-target, 3-beam X-ray system and a solid-state detector system. The TXRF-V310 includes Rigaku's patented XYθ sample stage system, an in-vacuum wafer robotic transfer system, and new user-friendly windows software. All of these contribute to higher throughput, higher accuracy and precision, and easy routine operation. Integrated VPD capability enables automatic VPD preparation of one wafer while a TXRF measurement is made on another wafer for the highest sensitivity and high throughput. VPD-TXRF eliminates the operator variability that may occur with ICP-MS, and VPD-TXRF can be completely controlled via factory automation. VPD recovery from selected areas, including the bevel area, is available. Optional Sweeping TXRF software enables mapping of the contaminant distribution over the wafer surface to identify "hot spots" that can be automatically re-measured at higher precision. Optional ZEE-TXRF capability overcomes the historical 15mm edge exclusion of original TXRF designs, enabling measurements to be made with zero edge exclusion. Optional BAC-TXRF capability enables fully-automated front-side and back-side TXRF measurements of 300mm wafers with non-contacting wafer flipping.