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Optics Express

Optics Express

  • Editor: Andrew M. Weiner
  • Vol. 21, Iss. 11 — Jun. 3, 2013
  • pp: 13547–13554

Digital projection photochemical etching defines gray-scale features

Chris Edwards, Kaiyuan Wang, Renjie Zhou, Basanta Bhaduri, Gabriel Popescu, and Lynford L. Goddard  »View Author Affiliations

Optics Express, Vol. 21, Issue 11, pp. 13547-13554 (2013)

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We demonstrate a maskless photochemical etching method that is capable of performing one-step etching of multi-level structures. This method uses a digital projector to focus an image onto the sample and define the etching pattern. By combining digital projection photochemical etching with diffraction phase microscopy, etch heights can be measured in situ in a non-destructive manner. This method is single shot, eliminating the need for expensive gray-scale masks or laser scanning methods. The etch rate is studied as a function of the wavelength and irradiance of the projected light. A lateral etch resolution of 2 μm is demonstrated by etching selected portions of the USAF-1951 target. Micropillars, multi-level plateaus, and an Archimedean spiral are etched, each in a single processing step, to illustrate the unique capabilities.

© 2013 OSA

OCIS Codes
(120.5050) Instrumentation, measurement, and metrology : Phase measurement
(220.3740) Optical design and fabrication : Lithography
(220.4000) Optical design and fabrication : Microstructure fabrication
(220.4610) Optical design and fabrication : Optical fabrication
(220.4241) Optical design and fabrication : Nanostructure fabrication

ToC Category:
Optical Design and Fabrication

Original Manuscript: April 19, 2013
Revised Manuscript: May 23, 2013
Manuscript Accepted: May 23, 2013
Published: May 30, 2013

Chris Edwards, Kaiyuan Wang, Renjie Zhou, Basanta Bhaduri, Gabriel Popescu, and Lynford L. Goddard, "Digital projection photochemical etching defines gray-scale features," Opt. Express 21, 13547-13554 (2013)

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  1. G. Wysocki, J. Heitz, and D. Bauerle, “Near-field optical nanopatterning of crystalline silicon,” Appl. Phys. Lett.84(12), 2025–2027 (2004). [CrossRef]
  2. Y. Jung, J. Kim, S. Jang, K. H. Baik, Y. G. Seo, and S.-M. Hwang, “Enhanced light extraction of nonpolar a-plane (11-20) GaN light emitting diodes on sapphire substrates by photo-enhanced chemical wet etching,” Opt. Express18(9), 9728–9732 (2010). [CrossRef] [PubMed]
  3. T. D. Lowes and D. T. Cassidy, “Photochemical Etching of N-Inp as a Function of Temperature and Illumination,” J. Appl. Phys.68(2), 814–819 (1990). [CrossRef]
  4. F. W. Ostermayer and P. A. Kohl, “Photoelectrochemical Etching of P-Gaas,” J. Electrochem. Soc.127, C394–C394 (1980).
  5. M. N. Ruberto, X. Zhang, R. Scarmozzino, A. E. Willner, D. V. Podlesnik, and R. M. Osgood, “The Laser-Controlled Micrometer-Scale Photoelectrochemical Etching of Iii-V Semiconductors,” J. Electrochem. Soc.138(4), 1174–1185 (1991). [CrossRef]
  6. P. A. Kohl, “Photoelectrochemical etching of semiconductors,” IBM J. Res. Develop.42(5), 629–638 (1998). [CrossRef]
  7. C. Youtsey, L. T. Romano, and I. Adesida, “Gallium nitride whiskers formed by selective photoenhanced wet etching of dislocations,” Appl. Phys. Lett.73(6), 797–799 (1998). [CrossRef]
  8. X. M. Ding, Y. Kawaguchi, T. Sato, A. Narazaki, and H. Niino, “Fabrication of microarrays on fused silica plates using the laser-induced backside wet etching method,” Langmuir20(22), 9769–9774 (2004). [CrossRef] [PubMed]
  9. S. Pissadakis, R. Böhme, and K. Zimmer, “Sub-micron periodic structuring of sapphire by laser induced backside wet etching technique,” Opt. Express15(4), 1428–1433 (2007). [CrossRef] [PubMed]
  10. M. R. Wang and H. Su, “Laser direct-write gray-level mask and one-step etching for diffractive microlens fabrication,” Appl. Opt.37(32), 7568–7576 (1998). [CrossRef] [PubMed]
  11. K. Sugioka, Y. Cheng, and K. Midorikawa, “Three-dimensional micromachining of glass using femtosecond laser for lab-on-a-chip device manufacture,” Appl. Phys., A Mater. Sci. Process.81(1), 1–10 (2005). [CrossRef]
  12. F. Chen, H. W. Liu, Q. Yang, X. H. Wang, C. Hou, H. Bian, W. W. Liang, J. H. Si, and X. Hou, “Maskless fabrication of concave microlens arrays on silica glasses by a femtosecond-laser-enhanced local wet etching method,” Opt. Express18(19), 20334–20343 (2010). [CrossRef] [PubMed]
  13. S. Ho, M. Haque, P. R. Herman, and J. S. Aitchison, “Femtosecond laser-assisted etching of three-dimensional inverted-woodpile structures in fused silica,” Opt. Lett.37(10), 1682–1684 (2012). [CrossRef] [PubMed]
  14. K. Zimmer, R. Bohme, A. Braun, B. Rauschenbach, and F. Bigl, “Excimer laser-induced etching of sub-micron surface relief gratings in fused silica using phase grating projection,” Appl. Phys., A Mater. Sci. Process.74(4), 453–456 (2002). [CrossRef]
  15. C. Vass, K. Osvay, and B. Hopp, “Fabrication of 150 nm period grating in fused silica by two-beam interferometric laser induced backside wet etching method,” Opt. Express14(18), 8354–8359 (2006). [CrossRef] [PubMed]
  16. J. de Boor, N. Geyer, J. V. Wittemann, U. Gösele, and V. Schmidt, “Sub-100 nm silicon nanowires by laser interference lithography and metal-assisted etching,” Nanotechnology21(9), 095302 (2010). [CrossRef] [PubMed]
  17. G. Popescu, Quantitative Phase Imaging of Cells and Tissues, Biophotonics (McGraw-Hill, New York, 2011).
  18. G. Popescu, T. Ikeda, R. R. Dasari, and M. S. Feld, “Diffraction phase microscopy for quantifying cell structure and dynamics,” Opt. Lett.31(6), 775–777 (2006). [CrossRef] [PubMed]
  19. C. Edwards, A. Arbabi, G. Popescu, and L. L. Goddard, “Optically monitoring and controlling nanoscale topography during semiconductor etching,” Light Sci Appl1(9), e30 (2012). [CrossRef]
  20. R. Zhou, G. Popescu, and L. L. Goddard, “22 nm node wafer inspection using diffraction phase microscopy and image post-processing,” SPIE8681, 8610G (2013).
  21. R. Zhou, C. Edwards, A. Arbabi, G. Popescu, and L. L. Goddard, “Detecting 20 nm defects in large area nano-patterns using optical interferometric microscopy,” submitted (2013).
  22. E. Spyratou, I. Asproudis, D. Tsoutsi, C. Bacharis, K. Moutsouris, M. Makropoulou, and A. A. Serafetinides, “UV laser ablation of intraocular lenses: SEM and AFM microscopy examination of the biomaterial surface,” Appl. Surf. Sci.256(8), 2539–2545 (2010). [CrossRef]
  23. S. J. Lim, W. Kim, and S. K. Shin, “Surface-Dependent, Ligand-Mediated Photochemical Etching of CdSe Nanoplatelets,” J. Am. Chem. Soc.134(18), 7576–7579 (2012). [CrossRef] [PubMed]
  24. D. E. Aspnes and A. A. Studna, “Dielectric functions and optical parameters of Si, Ge, GaP, GaAs, GaSb, InP, InAs, and InSb from 1.5 to 6.0 eV,” Phys. Rev. B27(2), 985–1009 (1983). [CrossRef]
  25. C. J. Hwang, “Optical Properties of N-Type GaAs. I. Determination of hole diffusion length from optical absorption and photoluminescence measurements,” J. Appl. Phys.40(9), 3731–3739 (1969). [CrossRef]
  26. S. Gupta, M. Y. Frankel, J. A. Valdmanis, J. F. Whitaker, and G. A. Mourou, “Subpicosecond carrier lifetime in GaAs grown by molecular beam epitaxy at low temperatures,” Appl. Phys. Rev.59, 3276–3278 (1991).

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