Journal of the European Optical Society - Rapid publications, Vol 5 (2010)

Matrixes of unconventional micro-optical components molded with etched silicon

J. Albero, C. Gorecki, L. Nieradko, B. Päivänranta, V. Gomez, H. Thienpont, N. Passilly

Abstract


This paper reports on a process to create microlenses characterized by unconventional footprints, spherical profiles and a wide range of sizes. Fabricated shapes such as squares, rectangles, ellipses, triangles and hexagons are tested alone as well as in matrix with high fulfill factors. The technique is based on molds from which microlenses are fabricated by UV-molding replication. The molds are produced by silicon wet isotropic etching in an acid solution. The process is mainly steered by temperature and etching concentration. The use of the proposed technology opens a wide range of geometries allowing the fabrication of microlenses matrices with high fulfill factors as well as microlenses for beam-shaping.

© The Authors. All rights reserved. [DOI: 10.2971/jeos.2010.10001]

Full Text: PDF

Citation Details


Cite this article

References


W. Welford, and R. Winston, "Nonconventional optical systems and the brightness theorem" Appl. Opt. 21, 1531-1533 (1982).

G. Petrovskii, "School of optical material science at the S. I. Vavilov State Optical Institute" J. Opt. Technol. 70, 855-856 (2003).

K. Iizuka, and M. Kawakita, "Unconventional Imaging" Opt. Photonics News 13, 61 (2002).

E. Marom, N. A. Vainos, A. A. Friesem, and J. W Goodman, "Unconventional Optical Elements for Information Storage, Processing and Communications" (Proceedings of the NATO Advanced Research Workshop, NATO, Tel Aviv, 1999).

S. Zhang, "A simple bi-convex refractive laser beam shaper" J. Opt. A - Pure Appl. Opt. 9, 945-950 (2007).

N. Passilly, M. Fromager, L. Mechin, C. Gunther, S. Eimer, T. Mohammed-Brahim, and K. At-Ameur, "1-D Laser beam shaping using an adjustable binary diffractive optical element" Opt. Commun. 241, 465-473 (2004).

S. Hsiao, C. Lee, and W. Fang, "Novel concave-based micro optical components" (Proceedings of the IEEE 21st International Conference on Micro Electro Mechanical Systems,Institute of Electrical and Electronics Engineers, Tucson, pp. 124-127, 2008).

C. T. Pan, and C. H. Su, "Fabrication of gapless triangular microlens array" Sensor. Actuat. A - Phys. 134, 631-640 (2007).

M. -C. Chou, C. T. Pan, S. C. Shen, M. -F. Chen, K. L. Lin, and S. -T. Wu, "A novel method to fabricate gapless hexagonal micro-lens array" Sensor. Actuat. A - Phys. 118, 298-306 (2005).

W. -Royall Cox, T. Cheng, and D. J. Hayes, "Micro-optics fabrication by ink-jet printing" Opt. Photonics News 12, 32-35 (2001).

T. -H. Lin, H. Yang, C. -K. Chao, and S. -Y. Hung, "New high fill-factor triangular microlens array fabrication method using UV proximity printing" Microsyst. Technol. 12, 1255-1261 (2009).

W. -H. Lee, and T. zel, "Laser Micro-Machining of Spherical and Elliptical 3-D Objects using Hole Area Modulation Method" I&SE Working Paper 07-021 (2007).

K. P. Larsen, J. T. Ravnkilde, and O. Hansen, "Investigations of the isotropic etch of an ICP source for silicon microlens mold fabrication" J. Micromech. Microeng. 15, 873-882 (2005).

J. Albero, L. Nieradko, C. Gorecki, H. Ottevaere, V. Gomez, H. Thienpont, J. Pietarinen, B. Pivnranta, and N. Passilly, "Fabrication of spherical microlenses by a combination of isotropic wet etching of silicon and molding techniques" Opt. Express 17, 6283-6292 (2009).

G. V. Vdovin, O. Akhzar-Mehr, P. M. Sarro, D. W. De Lima Monteiro, and M. Y. Loktev, "Arrays of spherical micromirrors and molded microlenses fabricated with bulk Si micromachining" Proc. SPIE 4945, 107-111 (2003).

B. Ezell, "Making microlens backlights grow up" Inform. Display. 17, 42-45 (2001).

A. Tripathi, T. V. Chokshi, and N. Chronis, "A high numerical aperture, polymer-based, planar microlens array" Opt. Express 17, 19908-19918 (2009).

H. Robbins, and B. Schwartz, "Chemical etching of Silicon I" J. Electrochem. Soc. 106, 505-508 (1959).

H. Robbins, and B. Schwartz, "Chemical etching of Silicon II" J. Electrochem. Soc. 107, 108-111 (1960).

B. Schwartz, and H. Robbins, "Chemical etching of Silicon III" J. Electrochem. Soc. 108, 365-372 (1961).

X. J. Shen, L. Pan, and L. Lin, "Microplastic embossing process: experimental and theoretical characterizations" Sensor. Actuat. A - Phys. 97-98, 428-433 (2002).

B. -K. Lee, D. S. Kim, and T. H. Kwom, "eplication of microlens arrays by injection molding" Microsyst. Technol. 10, 531-535 (2004).

P. Huang, T. Huang, Y. Sun, and S. Yang, "Fabrication of large area resin microlens arrays using gas-assisted ultraviolet embossing" Opt. Express 16, 3041-3048 (2008).

J. Pietarinen, V. Kalima, T. T. Pakkanen, and M. Kuittinen, "Improvement of UV-moulding accuracy by heat and solvent assisted process" Microelectron. Eng. 85, 263-270 (2008).

J. Pietarinen, S. Siitonen, N. Tossavainen, J. Laukkanen, and M. Kuittinen, "Fabrication of Ni-shims using UV-moulding as an intermediate step" Microelectron. Eng. 83, 492-498 (2006).

X. Zhang, Q. Tang, X. Yi, Z. Zhang, and X. Pei, "Cylindrical microlens array fabricated by argon ion-beam etching" Opt. Eng. 39, 3001 (2000).

K. R. Williams, and R. S. Muller, "Etch rates for Micromachining Processing" J. Microelectromech. S. 4, 256-269 (1996).

K. R. Williams, K. Gupta, and M. Wasilik, "Etch rates for Micromachining Processing - Part II" J. Microelectromech. S. 12, 761-778 (2003).

V. B. Svetovoy, J. W. Berenschot, and M. C. Elwenspoek, "Experimental investigation of anisotropy in isotropic silicon etching" J. Micromech. Microeng. 17, 2344-2351 (2007).

C. B. Shin, and D. J. Economou, "Forced and natural convection effects on the shape evolution of cavities during wet chemical etching" J. Electrochem. Soc. 138, 527-538 (1991).

X. G. Zhang, Electrochemistry of silicon and its oxide, (Kluwer Academic/ Plenum Publishers 2001).

H. K. Kuiken, J. J. Kelly, and P. H. L. Notten, "Etching profiles at resist edges I. Mathematical models for Diffusion-Controlled cases" J. Electrochem. Soc. 133, 1217-1226 (1986).