Rapid microcantilever-thickness determination by optical interferometry

Silicon microcantilevers are widely used in scanning-probe microscopy and in cantilever-sensing applications. However, the cantilever thickness is not well controlled in conventional lithography and, since it is also difficult to measure, it is the most important undefined factor in mechanical variability. An accurate method to measure this parameter is thus essential. We demonstrate the capability to measure microcantilever thicknesses rapidly (>1 Hz) and accurately (±2 nm) by optical interferometry. This is achieved with standard microscopy equipment and so can be implemented as a standard technique in both research and in batch control for commercial microfabrication. In addition, we show how spatial variations in the thickness of individual microcantilevers can be mapped, which has applications in the precise mechanical calibration of cantilevers for force spectroscopy.

[1]  E. Goering,et al.  Magnetic reflectometry of heterostructures , 2014, Journal of physics. Condensed matter : an Institute of Physics journal.

[2]  H. Lang,et al.  Direct detection of a BRAF mutation in total RNA from melanoma cells using cantilever arrays. , 2013, Nature nanotechnology.

[3]  M. Calleja,et al.  Tackling reproducibility in microcantilever biosensors: a statistical approach for sensitive and specific end-point detection of immunoreactions. , 2013, The Analyst.

[4]  James R Friend,et al.  Spring constant calibration of atomic force microscope cantilevers of arbitrary shape. , 2012, The Review of scientific instruments.

[5]  M. Reichling,et al.  Precise determination of force microscopy cantilever stiffness from dimensions and eigenfrequencies , 2012 .

[6]  M. Allen,et al.  Error in dynamic spring constant calibration of atomic force microscope probes due to nonuniform cantilevers , 2011, Nanotechnology.

[7]  Ing-Shouh Hwang,et al.  High throughput label-free platform for statistical bio-molecular sensing. , 2011, Lab on a chip.

[8]  Xin Huang,et al.  Microcantilever biosensors for chemicals and bioorganisms. , 2011, The Analyst.

[9]  A. Boisen,et al.  Cantilever-like micromechanical sensors , 2011 .

[10]  M. Calleja,et al.  High throughput optical readout of dense arrays of nanomechanical systems for sensing applications. , 2010, The Review of scientific instruments.

[11]  Laura M Lechuga,et al.  Microcantilever-based platforms as biosensing tools. , 2010, The Analyst.

[12]  M. Seah,et al.  Improved methods and uncertainty analysis in the calibration of the spring constant of an atomic force microscope cantilever using static experimental methods , 2009 .

[13]  V. Ostanin,et al.  Simultaneous readout of multiple microcantilever arrays with phase-shifting interferometric microscopy. , 2009, The Review of scientific instruments.

[14]  R. Dagastine,et al.  Variations in properties of atomic force microscope cantilevers fashioned from the same wafer , 2008, Nanotechnology.

[15]  J. Colton,et al.  Microcantilevers: sensing chemical interactions via mechanical motion. , 2008, Chemical reviews.

[16]  Javier Tamayo,et al.  Study of the Origin of Bending Induced by Bimetallic Effect on Microcantilever , 2007, Sensors.

[17]  M. Calleja,et al.  Role of the gold film nanostructure on the nanomechanical response of microcantilever sensors , 2007 .

[18]  W. Grange,et al.  Rapid and label-free nanomechanical detection of biomarker transcripts in human RNA , 2006, Nature nanotechnology.

[19]  W. Barth,et al.  A high-resolution optical study of cantilever heterostructure layer geometries , 2006 .

[20]  Joanna Schmit,et al.  Observation of nanoscale dynamics in cantilever sensor arrays , 2006 .

[21]  Martin P. Seah,et al.  The determination of atomic force microscope cantilever spring constants via dimensional methods for nanomechanical analysis , 2005 .

[22]  M. Sepaniak,et al.  Cantilever transducers as a platform for chemical and biological sensors , 2004 .

[23]  Y. Zhao,et al.  Influence of surface stress on frequency of microcantilever-based biosensors , 2004 .

[24]  Cagri A. Savran,et al.  Fabrication and characterization of a micromechanical sensor for differential detection of nanoscale motions , 2002 .

[25]  H. Lang,et al.  Multiple label-free biodetection and quantitative DNA-binding assays on a nanomechanical cantilever array , 2002, Proceedings of the National Academy of Sciences of the United States of America.

[26]  J. Sader,et al.  Calibration of rectangular atomic force microscope cantilevers , 1999 .

[27]  G. Stoney.  The Tension of Metallic Films Deposited by Electrolysis , 1909 .

[28]  E. Rosseel,et al.  SOI thickness uniformity improvement using wafer-scale corrective etching for silicon nano-photonic device , 2011 .

[29]  Y. Zhao,et al.  Influence of surface stress on frequency of microcantilever-based biosensors , 2005 .

[30]  Martyn C. Davies,et al.  Comparison of calibration methods for atomic-force microscopy cantilevers , 2002 .