{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,2,6]],"date-time":"2026-02-06T21:55:11Z","timestamp":1770414911594,"version":"3.49.0"},"reference-count":17,"publisher":"MDPI AG","issue":"10","license":[{"start":{"date-parts":[[2015,10,15]],"date-time":"2015-10-15T00:00:00Z","timestamp":1444867200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Micromachines"],"abstract":"<jats:p>In this paper, Isopropanol (IPA) availability during the anisotropic etching of silicon in Potassium Hydroxide (KOH) solutions was investigated. Squares of 8 to 40 \u00b5m were patterned to (100) oriented silicon wafers through DWL (Direct Writing Laser) photolithography. The wet etching process was performed inside an open HDPE (High Density Polyethylene) flask with ultrasonic agitation. IPA volume and evaporation was studied in a dynamic etching process, and subsequent influence on the silicon etching was inspected. For the tested conditions, evaporation rates for water vapor and IPA were determined as approximately 0.0417 mL\/min and 0.175 mL\/min, respectively. Results demonstrate that IPA availability, and not concentration, plays an important role in the definition of the final structure. Transversal SEM (Scanning Electron Microscopy) analysis demonstrates a correlation between microloading effects (as a consequence of structure spacing) and the angle formed towards the (100) plane.<\/jats:p>","DOI":"10.3390\/mi6101437","type":"journal-article","created":{"date-parts":[[2015,10,15]],"date-time":"2015-10-15T12:44:06Z","timestamp":1444913046000},"page":"1534-1545","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":35,"title":["Dynamic Wet Etching of Silicon through Isopropanol Alcohol Evaporation"],"prefix":"10.3390","volume":"6","author":[{"given":"Tiago","family":"Monteiro","sequence":"first","affiliation":[{"name":"Instituto de Engenharia de Sistemas de Computadores\u2013Microsystems and Nanotechnology (INESC\u2013MN), Rua Alves Redol, Lisboa 1000-029, Portugal"},{"name":"Microelectromechanical Systems Research Unit (CMEMS-UMinho), Universidade do Minho, Campus de Azurem, Guimar\u00e3es 4800-058, Portugal"}]},{"given":"Pamak\u0161tys","family":"Kastytis","sequence":"additional","affiliation":[{"name":"Instituto de Engenharia de Sistemas de Computadores\u2013Microsystems and Nanotechnology (INESC\u2013MN), Rua Alves Redol, Lisboa 1000-029, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-8441-3264","authenticated-orcid":false,"given":"Lu\u00eds","family":"Gon\u00e7alves","sequence":"additional","affiliation":[{"name":"Microelectromechanical Systems Research Unit (CMEMS-UMinho), Universidade do Minho, Campus de Azurem, Guimar\u00e3es 4800-058, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-2460-0556","authenticated-orcid":false,"given":"Gra\u00e7a","family":"Minas","sequence":"additional","affiliation":[{"name":"Microelectromechanical Systems Research Unit (CMEMS-UMinho), Universidade do Minho, Campus de Azurem, Guimar\u00e3es 4800-058, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-6913-6529","authenticated-orcid":false,"given":"Susana","family":"Cardoso","sequence":"additional","affiliation":[{"name":"Instituto de Engenharia de Sistemas de Computadores\u2013Microsystems and Nanotechnology (INESC\u2013MN), Rua Alves Redol, Lisboa 1000-029, Portugal"},{"name":"Departamento de F\u00edsica\u2013Instituto Superior T\u00e9cnico\u2013Universidade de Lisboa, Av. Rovisco Pais, Lisboa 1000, Portugal"}]}],"member":"1968","published-online":{"date-parts":[[2015,10,15]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"1906","DOI":"10.1016\/j.renene.2005.10.002","article-title":"Low-cost texturization of large-area crystalline silicon solar cells using hydrazine mono-hydrate for industrial use","volume":"31","author":"Gangopadhyay","year":"2006","journal-title":"Renew. Energy"},{"key":"ref_2","unstructured":"Sparber, W., Schultz, O., Biro, D., Emanuel, G., Preu, R., Poddey, A., and Borchert, D. (2003, January 18). Comparison of texturing methods for monocrystalline silicon solar cells using KOH and Na2CO3. Proceedings of 3rd World Conference on Photovoltaic Energy Conversion, Osaka, Japan."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"P419","DOI":"10.1149\/2.005311jss","article-title":"Fabrication of inverted-pyramid silicon nanopore arrays with three-step wet etching","volume":"2","author":"Deng","year":"2013","journal-title":"ECS J. Solid State Sci. Technol."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"472","DOI":"10.1016\/j.apsusc.2010.07.014","article-title":"Reflectivity of porous-pyramids structured silicon surface","volume":"257","author":"Xiao","year":"2010","journal-title":"Appl. Surf. Sci."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"221","DOI":"10.1007\/s00542-013-1859-z","article-title":"Silicon 45\u00b0 micromirrors fabricated by etching in alkaline solutions with organic additives","volume":"20","author":"Rola","year":"2014","journal-title":"Microsyst. Technol."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"130","DOI":"10.1016\/j.jconrel.2014.04.052","article-title":"Current advances in the fabrication of microneedles for transdermal delivery","volume":"185","author":"Indermun","year":"2014","journal-title":"J. Control. Release"},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"074008","DOI":"10.1088\/0960-1317\/19\/7\/074008","article-title":"Fabrication technology for silicon-based microprobe arrays used in acute and sub-chronic neural recording","volume":"19","author":"Herwik","year":"2009","journal-title":"J. Micromech. Microeng."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"3612","DOI":"10.1149\/1.2086277","article-title":"Anisotropic etching of crystalline silicon in alkaline solutions: I. Orientation dependence and behavior of passivation layers","volume":"137","author":"Seidel","year":"1990","journal-title":"J. Electrochem. Soc."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"120","DOI":"10.1539\/joh.12-0143-CS","article-title":"Tetramethylammonium hydroxide poisoning during a pallet cleaning demonstration","volume":"55","author":"Park","year":"2012","journal-title":"J. Occup. Health"},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"138","DOI":"10.1016\/S0924-4247(01)00648-3","article-title":"The effect of isopropyl alcohol on etching rate and roughness of (1 0 0) si surface etched in KOH and TMAH solutions","volume":"93","author":"Zubel","year":"2001","journal-title":"Sens. Actuators A Phys."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"26","DOI":"10.1088\/0960-1317\/13\/1\/304","article-title":"Effective roughness reduction of {100} and {311} planes in anisotropic etching of {100} silicon in 5% TMAH","volume":"13","author":"Drago","year":"2003","journal-title":"J. Micromech. Microeng."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"549","DOI":"10.1016\/j.sna.2003.11.010","article-title":"Etch rates and morphology of silicon (h k l) surfaces etched in KOH and KOH saturated with isopropanol solutions","volume":"115","author":"Zubel","year":"2004","journal-title":"Sens. Actuators A Phys."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"635","DOI":"10.1007\/s00542-012-1675-x","article-title":"Impact of alcohol additives concentration on etch rate and surface morphology of (100) and (110) si substrates etched in koh solutions","volume":"19","author":"Rola","year":"2013","journal-title":"Microsyst. Technol."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"956","DOI":"10.1149\/1.2119866","article-title":"A raman study of etching silicon in aqueous KOH","volume":"130","author":"Palik","year":"1983","journal-title":"J. Electrochem. Soc."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"263","DOI":"10.1016\/j.sna.2004.07.015","article-title":"Effects of mechanical agitation and surfactant additive on silicon anisotropic etching in alkaline KOH solution","volume":"119","author":"Yang","year":"2005","journal-title":"Sens. Actuators A Phys."},{"key":"ref_16","unstructured":"INESC-MN. Available online: http:\/\/www.inesc-mn.pt."},{"key":"ref_17","unstructured":"Waser, R., Keller, H., and Erb, U. (2003). Nanoelectronics and Information Technology: Advanced Electronic Materials and Novel Devices, John Wiley & Sons, Inc."}],"container-title":["Micromachines"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2072-666X\/6\/10\/1437\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T20:50:11Z","timestamp":1760215811000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2072-666X\/6\/10\/1437"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2015,10,15]]},"references-count":17,"journal-issue":{"issue":"10","published-online":{"date-parts":[[2015,10]]}},"alternative-id":["mi6101437"],"URL":"https:\/\/doi.org\/10.3390\/mi6101437","relation":{},"ISSN":["2072-666X"],"issn-type":[{"value":"2072-666X","type":"electronic"}],"subject":[],"published":{"date-parts":[[2015,10,15]]}}}