Low-stiffness silicon cantilevers with integrated heaters and piezoresistive sensors for high-density AFM thermomechanical data storage

• Published in: Journal of microelectromechanical systems Vol. 7; no. 1; pp. 69 - 78
• Main Authors: Chui, B.W., Stowe, T.D., Yongho Sungtaek Ju, Goodson, K.E., Kenny, T.W., Mamin, H.J., Terris, B.D., Ried, R.P., Rugar, D.
• Format: Journal Article
• Language: English
• Published: New York, NY IEEE 01.03.1998; Institute of Electrical and Electronics Engineers
• Subjects: Applied sciences; Atomic force microscopes; Atomic force microscopy; Atomic measurements; Electric variables measurement; Electronics; Exact sciences and technology; Instruments, apparatus, components and techniques common to several branches of physics and astronomy; Memory; Miscellaneous; Physics; Piezoresistance; Predictive models; Resistance heating; Scanning probe microscopes, components and techniques; Silicon; Solid modeling; Storage and reproduction of information; Thermomechanical processes; Atomic force microscopy; Reading; Piezoresistive sensor; Thermodynamic model; Data storage; Silicon; Modeling; Cantilever beam
• ISSN: 1057-7157; 1941-0158
• DOI: 10.1109/84.661386

Single-crystal silicon cantilevers 1 /spl mu/m thick have been demonstrated for use in high-density atomic-force microscopy (AFM) thermomechanical data storage. Cantilevers with integrated piezoresistive sensors were fabricated with measured sensitivities /spl Delta/R/R up to 7.5/spl times/10/sup -7/ per /spl Aring/ in close agreement with theoretical predictions. Separate cantilevers with integrated resistive heaters were fabricated using the same basic process. Electrical and thermal measurements on these heating devices produced results consistent with ANSYS simulations. Geometric variants of the cantilever were also tested in order to study the dependence of the thermal time constant on device parameters. Depending on the design, time constants as low as 1 /spl mu/s were achieved. A thermodynamic model was developed based on the cantilevers geometry and material properties, and the model was shown to predict device behavior accurately. A comprehensive understanding of cantilever functionality enabled us to optimize the cantilever for high-speed thermomechanical recording.