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The fully automated industrial WLI-AFM system

Park NX-Hybrid WLI is the first-ever AFM with built-in WLI profilometry for semiconductor and related manufacturing quality assurance, process control for semiconductor front-end, back-end up to advanced packaging, and R&D metrology. It is for those that require high throughput measurements over a large area that can zoom down to nanometer-scale regions with sub-nano resolution and ultra-high accuracy.


The two best complementary technologies for semiconductor metrology

  • WLI: White light interferometry is an optical technique that can image a very wide area, very fast, producing high throughput measurements.
  • AFM: Atomic force microscopy is a scanning probe technique that delivers the highest nanoscale resolution measurements even for transparent materials.

 Measurement AreaSpeedLateral ResolutionVertical ResolutionAccuracy
WLI Large High Low High Low
AFM Small Low High Very High High
Measurement Area Large Small
Speed High Low
Lateral Resolution Low High
Vertical Resolution High Very High
Accuracy Low High

WLI and AFM complement each other in field of view, resolution, and speed

WLI applications requiring much higher resolution and accuracy beyond WLI capability

  • Advanced CMP metrology and monitoring
  • Advanced packaging
  • Hot-spot and defect detection on full reticle die
  • Wafer level metrology

AFM applications requiring much higher throughput over much larger areas

  • In-line Wafer Metrology
  • Long Range Profiling for CMP Characterization
  • Sub-Angstrom Surface Roughness Control
  • Wafer Inspection and Analysis


NX-Hybrid WLI features

Park WLI System

  • Park WLI supports WLI and PSI modes (PSI mode is supported with Motorized Filter Changer)
  • Available objectives lens magnification: 2.5X, 10X, 20X, 50X, 100X
  • Two objective lenses can be automatically replaced by Motorized Linear Lens Changer

WLI Optical Interferometry

  • The height of sample surface at each pixel can be calculated from the light intensity variation due to interference while scanning the height of Mirau objective lens
  • White light interferometry (WLI) and phase shifting interferometry (PSI) are two popular techniques for surface characterization

NX-Hybrid WLI Applications

Hotspot Detection and Review

Fast survey of hotspots and automated review of hotspot defects

  • Hotspots of a patterned structure can be detected by comparing images of reference and target sample areas
  • High speed “hotspot detection” by WLI enables fast localization for defect sites for high resolution AFM review