A piezoresistive cantilever for lateral force detection fabricated by a monolithic post-CMOS process

This paper presents a post-CMOS process to monolithically integrate a piezoresistive cantilever for lateral force detection and signal processing circuitry. The fabrication process includes a standard CMOS process and one more lithography step to micromachine the cantilever structure in the post-CMOS process. The piezoresistors are doped in the CMOS process but defined in the post-CMOS micromachining process without any extra process required. A partially split cantilever configuration is developed for the lateral force detection. The piezoresistors are self-aligned to the split cantilever, and therefore the width of the beam is only limited by lithography. Consequently, this kind of cantilever potentially has a high resolution. The preliminary experimental results show expected performances of the fabricated piezoresistors and electronic circuits.

[2]  Gil U. Lee,et al.  A high-sensitivity micromachined biosensor , 1997, Proc. IEEE.

[3]  N. C. MacDonald,et al.  SCREAM MicroElectroMechanical Systems , 1996 .

[4]  Anthony J. Peyton,et al.  Analog Electronics with Op amps: A Guide to Circuit Design , 1993 .

[5]  I. Shimoyama,et al.  Force sensing submicrometer thick cantilevers with ultra-thin piezoresistors by rapid thermal diffusion , 2004 .

[6]  N. C. MacDonald,et al.  SCREAM I: A single mask, single-crystal silicon, reactive ion etching process for microelectromechanical structures , 1994 .

[7]  O. Hansen,et al.  Optimization of sensitivity and noise in piezoresistive cantilevers , 2002 .

[8]  J. F. Creemer,et al.  Piezoresistive Cantilever Beam for Force Sensingin Two Dimensions , 2007, IEEE Sensors Journal.

[9]  J. Xi,et al.  Self-assembled microdevices driven by muscle , 2005, Nature materials.

[10]  Susumu Sugiyama,et al.  Single crystal silicon nano-wire piezoresistors for mechanical sensors , 2002 .

[11]  P. Renaud,et al.  Contraction Measurements of Cardiomyocytes Grown on Silicon Cantilevers , 2007, TRANSDUCERS 2007 - 2007 International Solid-State Sensors, Actuators and Microsystems Conference.

[12]  Karabi Biswas,et al.  MEMS Capacitive Accelerometers , 2007 .

[13]  Sidewall-implanted dual-axis piezoresistive cantilever for AFM data storage readback and tracking , 1998, Proceedings MEMS 98. IEEE. Eleventh Annual International Workshop on Micro Electro Mechanical Systems. An Investigation of Micro Structures, Sensors, Actuators, Machines and Systems (Cat. No.98CH36176.

[14]  Tae Song Kim,et al.  Fabrication of Microcantilever Sensors Actuated by Piezoelectric Pb(Zr0.52Ti0.48)O3 Thick Films and Determination of Their Electromechanical Characteristics , 2005 .

[15]  Pasqualina M. Sarro,et al.  Lateral nano-Newton force-sensing piezoresistive cantilever for microparticle handling , 2006 .

[16]  Thomas W. Kenny,et al.  Independent detection of vertical and lateral forces with a sidewall-implanted dual-axis piezoresistive cantilever , 1998 .

[17]  J. F. Creemer.  The effect of mechanical stress on bipolar transistor characteristics , 2002 .

[18]  Denton J. Dailey,et al.  Operational Amplifiers and Linear Integrated Circuits: Theory and Applications , 1990 .