Tesis doctoral de Jaume Verd Martorell
Resonant beams structures are very attractive transducers for physical, chemical and biological sensors based on micro-/nanoelectromechanical systems (m-/nems) due to its simplicity, wide range of sensing domains, and extremely high sensitivity. This ph.D. Thesis is focused on the design, fabrication and characterization of monolithic cmos-mems based on sub-micrometer scale resonant beams for its application in ultrasensitive mass detection with a portable device. The resonators operate in dynamic mode where the mass is measured as a change of its resonant frequency which is electrostatically induced and capacitive readout by means of a monolithically integrated cmos circuitry. two different technological approaches are considered to fabricate sub-micrometer scale resonant beams on pre-processed cmos chips allowing a monolithic integration: (i) nano post-processing of the cmos chip to obtain the resonant beams or (ii) definition of the resonant beams at the same time that the cmos circuits. From both approaches, metal and polysilicon devices exhibiting unprecedented mass sensitivities (for monolithic cmos sensors) in the atto-/zeptogram range are reported. Comparison of the results following both approaches is given. high-sensitivity readout cmos circuits are specifically designed to amplify the capacitive current with transimpedance gains (using a commercial 0.35- m cmos technology) up to 120 db at 10 mhz allowing to detect the resonator displacement with resolutions up to ~10 fm/ hz which are similar than the best reported optical readout systems without the need of a bulky setup. electrical characterization, in air and in vacuum conditions, of fabricated cmos-mems devices is presented corroborating the ability of the presented monolithic approach in measuring the frequency characteristics of sub-micrometer scale beam resonators. Optimal electrostatic transduction is achieved measuring electrical frequency responses with high peaks (up to 20 db or more) and
Datos académicos de la tesis doctoral «Monolithic cmos-mems resonant beams for ultrasensitive mass detection«
- Título de la tesis: Monolithic cmos-mems resonant beams for ultrasensitive mass detection
- Autor: Jaume Verd Martorell
- Universidad: Autónoma de barcelona
- Fecha de lectura de la tesis: 18/04/2008
Dirección y tribunal
- Director de la tesis
- Nuria Barniol Beumala
- Tribunal
- Presidente del tribunal: Francisco Serra mestres
- jaume Segura fuster (vocal)
- adoración Rueda rueda (vocal)
- Tamayo de Miguel Javier (vocal)