title: Spatially Multiplexed Micro-Spectrophotometry in Bright Field Mode for Thin Film Characterization.
abstract: Thickness characterization of thin films is of primary importance in a variety of nanotechnology applications, either in the semiconductor industry, quality control in nanofabrication processes or engineering of nanoelectromechanical systems (NEMS) because small thickness variability can strongly compromise the device performance. Here, we present an alternative optical method in bright field mode called Spatially Multiplexed Micro-Spectrophotometry that allows rapid and non-destructive characterization of thin films over areas of mm² and with 1 μm of lateral resolution. We demonstrate an accuracy of 0.1% in the thickness characterization through measurements performed on four microcantilevers that expand an area of 1.8 mm² in one minute of analysis time. The measured thickness variation in the range of few tens of nm translates into a mechanical variability that produces an error of up to 2% in the response of the studied devices when they are used to measure surface stress variations.
authors.affiliation: IMM-Instituto de Microelectr&#243;nica de Madrid (CNM-CSIC), Isaac Newton 8, PTM, Tres Cantos, E-28760 Madrid, Spain. valerio.pini@imm.cnm.csic.es.
authors.forename: Valerio
authors.initials: V
authors.lastname: Pini
authors.affiliation: IMM-Instituto de Microelectr&#243;nica de Madrid (CNM-CSIC), Isaac Newton 8, PTM, Tres Cantos, E-28760 Madrid, Spain. priscila@imm.cnm.csic.es.
authors.forename: Priscila M
authors.initials: PM
authors.lastname: Kosaka
authors.affiliation: IMM-Instituto de Microelectr&#243;nica de Madrid (CNM-CSIC), Isaac Newton 8, PTM, Tres Cantos, E-28760 Madrid, Spain. jose.ruz@imm.cnm.csic.es.
authors.forename: Jose J
authors.initials: JJ
authors.lastname: Ruz
authors.affiliation: IMM-Instituto de Microelectr&#243;nica de Madrid (CNM-CSIC), Isaac Newton 8, PTM, Tres Cantos, E-28760 Madrid, Spain. oscar.malvar@csic.es.
authors.forename: Oscar
authors.initials: O
authors.lastname: Malvar
authors.affiliation: IMM-Instituto de Microelectr&#243;nica de Madrid (CNM-CSIC), Isaac Newton 8, PTM, Tres Cantos, E-28760 Madrid, Spain. mario.encinar@csic.es.
authors.forename: Mario
authors.initials: M
authors.lastname: Encinar
authors.affiliation: IMM-Instituto de Microelectr&#243;nica de Madrid (CNM-CSIC), Isaac Newton 8, PTM, Tres Cantos, E-28760 Madrid, Spain. jtamayo@imm.cnm.csic.es.
authors.forename: Javier
authors.initials: J
authors.lastname: Tamayo
authors.affiliation: IMM-Instituto de Microelectr&#243;nica de Madrid (CNM-CSIC), Isaac Newton 8, PTM, Tres Cantos, E-28760 Madrid, Spain. mcalleja@imm.cnm.csic.es.
authors.forename: Montserrat
authors.initials: M
authors.lastname: Calleja
keywords: mass sensing; microcantilever sensors; microspectrophotometry; nanomechanical sensors; nanomechanics; resonators; surface stress; thin film