Download as PDF, PPTX
White Light Interferometry 3D Surface Profiler
- 1.
- 2. Theory background • Interferometeruses the superposition principle to combine waves in a way to extract information from the wave fronts. • The position of the zero order interference fringe is independent of wavelength • A broadband “white light” source is used to illuminate the test and reference surfaces 2 reference surfaces • The reference beam is reflected by the reference mirror, while the measurement beam is reflected or scattered from the test surface. • Reconstruction of the surface based on the fringes snapped by the camera
- 3. Intensity = A+ B cos(φ) φ ∽ z 3D topographic image of the object surface Light Plane Mirau microscope objective 3 Convergent lens Plane reference mirror Reference surface z Object surface Interferences
- 4. • Step-height androughness measurement • White light interferometric profilometer • Variable field of view due to revolver objectives • High speed: full image recorded within seconds Semilab Optical Profilometer 4 • High speed: full image recorded within seconds • Sub-micron lateral resolution • Sub-nm height resolution • CCD color camera • Low sensitivity to vibrations • Non-destructive
- 5. WLI Camera resolution: 1024x1024(2048 x 1088) Pixel Size (on the sensor): 5.5µmx5.5µm Acquisition speed: 500 fps (340 fps) Measurement time (without motion): <1 sec Depth resolution : < 0.1 nm Repeatability: σ=0.3 - 6 nm depend on sample Specification: www.semilab.com Repeatability: σ=0.3 - 6 nm depend on sample Multiple heads configuration available Color Camera option 9/21/2015 5 Objective (3D) 50x 20x 10x Maximum FOV (µm) 284x150 568x300 1136x600 Best optical resolution (Rayleigh definition) (µm) 0.5 0.7 0.9 Field of views:
- 6.
- 7. Step-height measurement 7 Critical dimensioninspection of step-height like profile
- 8. Flat Panel Transistor 8 Criticaldimension of flat panel transistor
- 9. Diamond cut solarcell wafer 1700 nm 9 Solar cell wafer inspection of saw mark, surface roughness and features. 0
- 10. Metal surface 3000 nm 10 Metalsurface inspection of screatches, surface roughness and features. 0
- 11. Critical dimension ofMEMS device 400 nm 11 0
- 12. Optical surface withdust 1000 nm 12 0
- 13. Recent WLI demoresult: spacers height in FPD structures 6000 nm www.semilab.com9/21/2015 13 0
- 14. Measurements Positions Repeatibility measurement www.semilab.com9/21/201514 The Critical dimensions (Top and Bottom) are measured along the yellow axes (nm)
- 15. 3D view ofFPD structures www.semilab.com 15
- 16.
- 17.
- 18. Surface roughness andwaviness 200 nm RMS=4.797 nm www.semilab.com 18 0 RMS=36.273 nm
- 19. Surface roughness andwaviness II. RMS=4.797 nm www.semilab.com 19 RMS=36.273 nm
- 20.
- 21. Surface roughness andwaviness Bandpass (0.027 to 2.75 um) www.semilab.com 21 Bandpass (2.75 to 555 um)
- 22. RMS=9.433 nm www.semilab.com 22 RMS=27.298 nm
- 23.
- 24. Surface roughness andwaviness Bandpass (0.027 to 2.75 um) www.semilab.com 24 Bandpass (2.75 to 555 um)
- 25.
- 26.
- 27. Surface roughness andwaviness Bandpass (0.027 to 2.75 um) www.semilab.com 27 Bandpass (2.75 to 555 um)
- 28.
- 29. • Semilab iscapable to deliver state of art 3d surface profiling metrology using white light interferometry • Best resolution available : high resolution camera can deliver data up to 2 Megapixels, in less than 3s aquisition time Conclusions www.semilab.com in less than 3s aquisition time • Semilab wli technology proved to work for various industrial applications in the flat panel, solar cell and semiconductor area • Excellent repeatability is proven to be in the range of few nm-s 29