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 Area | Speed | Lateral Resolution | Vertical Resolution | Accuracy | |
|---|---|---|---|---|---|
| WLI | Large | High | Low | High | Low |
| AFM | Small | Low | High | Very High | High |
| WLI | AFM | |
|---|---|---|
| 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
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