High Aspect Ratio Sio2 Capillary Based On Silicon Etching And Thermal Oxidation Process For Optical Modulator

{"references": ["G.D. Antoio, L.P. Jose, N. Manuel, P. Antonio, R. Santiago and O. Luis,\n\"Locating moving object in car-driving sequences\", J. Image and video\nprocessing, 24, pp. 1-23, 2014.", "H. Karaoguz, O. Erkent and H. I. Bozma, \"RGB-D based place\nrepresentation in topological maps\", J. Machine Vision and applications,\n25, pp. 1913-1927, 2014.", "J. Han, D. Wang, L. Shao, X. Qian, G. Cheng and J. Han, \"Image visual\nattention computation and application via the learning of object\natributes\", J. Machine Vision and applications, 25, pp. 1671-1683, 2014.", "F. Liang, S.Tang, Y. Zhang, Z. Xu and J. Li, \"Pedestrian detection based\non sparse coding and transfer learning\", J. Machine Vision and\napplications, 25, pp. 1697-1709, 2014.", "Ng. Ren, L. Marc, B. Mathieu, D. Gene, H. Mark, H. Pat, D. Duval,\n\"Light field photography with a hand held plenoptic camera\", Stanford\nTech Report CTSR 2005-2.", "Ph. Nussbaum, R. Volkel, M. Eisner and S. Haselbeck, \" Design,\nfabrication and testing of microlens arrays for sensors and\nmicrosystems\", Pure and applied optics: Journal of the European\noptical society part A, 6, pp. 617-636, 1997.", "A. Levin, R. Fergus, F. Durand, B. Freeman, \"Image and Depth from a\nConventional Camera with a Coded Aperture\", in Proceedings of\nSIGGRAPH, 2009.", "J. Heikenfeld, K. Zhou, E. Kreit, B. Raji, S. Yang, B. Sun, A. Milarcik,\nL. Clapp and R. Schwartz, \"Electrofluidic displays using Young-Laplace transposition of brilliant pigment dispersions\" J. Nature photon, 3, pp.\n292-296 2009.", "G. Beni and S. Hackwood, \"Electro-wetting displays\", J. Appl. Phys.\nLett. 38, 207, 1981.\n[10] A Szekeres and P Danesh, \"Mechanical stress in SiO2/Si structures\nformed by thermal oxidation of amorphous and crystalline silicon\",\nJournal of Semicond. Sci. Technol, 11, pp. 1225-1230, 1996.\n[11] N.I. Morimoto, and J.W. Swart, \"Development of a cluster tool and\nanalysis of deposition of silicon oxide by TEOS O2 PECVD\", MRS\nproceedings, p. 263, 1996.\n[12] N.V. Toan, T. Kubota, H. Sekhar, S. Samukawa and T. Ono,\n\"Mechanical quality factor enhancement in a silicon micromechanical\nresonator by low-damage process using neutral beam etching\ntechnology\", J. Micromech. Microeng, 24, 085005, 2014.\n[13] H. Ohtake, H. Ishihara, T. Fuse, A. Koshiishi and S. Samukawa, \"Highly\nselective and high rate SiO2 etching using argon-added C2F4/CF3I\nplasma\", Journal of vacuum science & technology B, 21, p. 2142, 2003.\n[14] C. Chang, T. Abe and M. Esashi, \"Trench filling characteristics of low\nstress TEOS/ozone oxide deposited by PECVD and SACVD\", J.\nMicrosystem Technologies, 10, pp. 97-102, 2004.\n[15] N.V. Toan, M. Toda, Y. Kawai and T. Ono, \"A capacitive silicon\nresonator with a movable electrode structure for gap width reduction\", J.\nMicromech. Microeng, 24, 025006, 2014.\n[16] N.V. Toan, H. Miyashita, M. Toda, Y. Kawai and T. Ono, \"Fabrication\nof an hermetically packaged silicon resonator on LTCC substrate\", J.\nMicrosystem Technologies, 19, pp. 1165-1175, 2013.\n[17] D. Andriukaitis and R. Anilionis, \"Oxidation process and different\ncrystallographic plane orientation dependence simulation in micro and\nnano strucutre\", In proceedings of conf. on information technology and\ninterfaces, pp. 573-578, 2007.\n[18] Y. Suzuki, K. Totsu, M. Moriyama, M. Esashi and S. Tanaka,\n\"Free-standing subwavelength grid infrared rejection filter of 90 mm\ndiameter for EUV light source\", In proceedings of the 27th IEEE\ninternational conference on micro electro mechanical systems, pp.\n482-485, 2014.\n[19] C. Con, J. Zhang and B. Cui, \"Nanofabrication of high aspect ratio\nstructures using an evaporated reisist containing metal\", J.\nNanotechnology, 25, p. 17531, 2014.\n[20] S.Y. Chou, P.R. Krauss and P.J. Renstrom, \"Imprint lithography with\n25-nanometer resolution\", Science, 272, pp. 85-87, 1996.\n[21] J. Heikenfeld, K. Zhou, E. Kreit, B. Raji, S. Yang, B. Sun, A. Milarcik,\nL. Clapp and R. Schwartz, \"Electrofluidic displays using Young-Laplace\ntransposition of brilliant pigment dispersions\" J. Nature photon, 3, pp.\n292-296 2009.\n[22] B. Berge and J. Peseux, \"Variable focal lens controlled by an external\nvoltage: an application of electrowetting\", Eur. Phys. J. E, 3, pp.\n159-163, 2000.\n[23] J. Lee, H. Moon, J. Fowler, T. Schoellhammer, and C.J. Kim,\n\"Electrowetting and electrowetting on dielectric for micrscale liquid\nhandling\", J. Sensor Actuator A, 95, pp. 259-268, 2002."]}

This paper presents the design and fabrication of an<br> optical window for an optical modulator toward image sensing<br> applications. An optical window consists of micrometer-order SiO2<br> capillaries (porous solid) that can modulate transmission light<br> intensity by moving the liquid in and out of porous solid. A high<br> optical transmittance of the optical window can be achieved due to<br> refractive index matching when the liquid is penetrated into the<br> porous solid. Otherwise, its light transmittance is lower because of<br> light reflection and scattering by air holes and capillary walls. Silicon<br> capillaries fabricated by deep reactive ion etching (DRIE) process are<br> completely oxidized to form the SiO2 capillaries. Therefore, high<br> aspect ratio SiO2 capillaries can be achieved based on silicon<br> capillaries formed by DRIE technique. Large compressive stress of<br> the oxide causes bending of the capillary structure, which is reduced<br> by optimizing the design of device structure. The large stress of the<br> optical window can be released via thin supporting beams. A 7.2 mm<br> x 9.6 mm optical window area toward a fully integrated with the<br> image sensor format is successfully fabricated and its optical<br> transmittance is evaluated with and without inserting liquids (ethanol<br> and matching oil). The achieved modulation range is approximately<br> 20% to 35% with and without liquid penetration in visible region<br> (wavelength range from 450 nm to 650 nm).