Wafer surface contamination metrology by TXRF

Measurement of trace elemental surface contamination


TXRF analysis can gauge contamination in all fab processes, including cleaning, litho, etch, ashing, films, etc. The TXRF-450 can measure elements from Na through U with a single-target, 3-beam X-ray system and a solid-state detector system.

The TXRF-450 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.

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 450mm wafers with non-contacting wafer flipping.


  • Quick contamination inspection for semiconductor processes
  • Accepts 450 mm and 300 mm wafers
  • Wide range of analytical elements (Na~U)
  • Light-element sensitivity (for Na, Mg, and Al)
  • Single target 3-beam method and XYθ stage are unique to Rigaku, enabling highly accurate ultra trace analysis over the entire wafer surface
  • Import measurement coordinates from defect inspection tools for follow-up analysis

TXRF-450 specifications

  • Size of wafer: 450 mm and 300 mm
  • Rotating-anode X-ray source
  • Sample stage: XY θ stage
  • Solid-state detector
  • Oil-free electrical transformer
  • Three-beam excitation
  • Automatic optics alignment
  • Data import from external surface defect inspection tool

TXRF-450 accessories

  • GEM-450 automation software for full factory automation
  • SP-TXRF capability enables mapping of the entire wafer surface
  • ZEE-TXRF capability enables measurements to zero edge exclusion
  • BAC-TXRF capability enables fully-automated front-side and back-side measurements

TXRF-450 applications

  • Determination of the contaminant element spatial distribution (wafer mapping)
    • Contamination distribution is seen at a glance by individual element maps and overlapping element views
    • Average contamination is calculated over the entire wafer surface
    • High-precision measurements can be carried out automatically on contaminated spots found by whole-wafer surface screening
  • For routine analysis on particular points: Direct-TXRF of designated coordinates
    • Correct contamination levels are reported at all points on a wafer by avoiding diffraction interference
    • Detection of transition metals at the 10⁹ atoms/ cm² level is possible (500 sec measurement)
    • Using a high-power rotating-anode X-ray source, three-times higher throughput is achieved compared with a sealed-tube source
    • Light elements, transition metals, and heavy elements are measured seamlessly without switching between multiple X-ray tubes

(Hold down CTRL key
to select multiple items)

Name (first/last):
Phone: Ext:
Street address:
State/Province/Region: (use two-letter abbreviations for US)
Zip/Postal Code:
Additional comments

 (no URLs allowed)