The Phase Focus Virtual Lens® operates in both reflection and transmission modes. Please see the application notes at the bottom of the page for some specific examples of the technology.
The simplest optical arrangement relevant for reflection metrology consists of a coherent light source; a moveable X-Y stage; an aperture; a beam-splitter and a detector.
Phase Focus Virtual Lens® benefits for optical reflection metrology include:
- Non-contact
- Non-destructive
- No lens required
- No lens-related aberrations, asymmetries or distortions
- Substantive cost savings (no objective lens optics costs)
- Post-acquisition focusing: “Perfect focus every time”
- No further mechanical movement required for multi-focal-plane studies
- High resolution wide-area metrology without need for stitching
- Arbitrarily large user-defined scan area
- Uniform background intensity
- Independent of source illumination uniformity
- Very high contrast imaging of transparent and sub-surface features: “Seeing the invisible”
- High contrast images of transparent films and depositions
- Characterisation of material types (e.g.: dielectric constant) independent of surface topography
- Characterisation of surface topography independent of material types
- High resolution
- Lateral: 0.9µ typical
- Topographic: 0.02 radians phase sensitivity (6Å typical depth sensitivity)
- “Point-and-click” operation
- Performance is essentially operator-independent
- Straightforward integration with existing non-contact optical metrology tools
