Microeletronic pressure sensor based on the transversal piezoresistive effect in silicon / Sensor de pressão microeletronico baseado no efeito piezoresistivo transversal em silicio

AUTOR(ES)
DATA DE PUBLICAÇÃO

2008

RESUMO

This work describes a CMOS-Compatible multiterminal piezoresistive pressure sensor based on the transversal piezoresistive effect, which consists of a piezotransducer fabricated on a membrane. The layout of this piezoelement is designed in such a way that its sensitivity is improved by maximizing the effect of the mechanical stress over the equipotential lines distribution in its active region. We performed Element Finite analyses in both membrane and piezoelement designs. The sensor was fabricated using two different technologies: CMOS 0,35 ?m AMS process (Austria Mikro Systeme International) - supported by the Fapesp Multi-User Project - and CCS/Unicamp process (Center for Semiconductor Components). In the AMS process, we realized a diaphragm by reducing the thickness of the die through a mechanical polishing process. In the sensor fabricated at CCS/Unicamp process, a backside bulk micro-machining was performed by using an automated KOH chemical etching apparatus, which provides a well-controlled anisotropic etching process. The sensor sensitivity is proportional to the number of input current terminals. The sensor sensitivity dependence related to its geometry is minimized even for a wide range of the sensor layout´s aspect-ratio. In the AMS process, sensor s sensitivity amounted to 0.24 mV/psi and in the CCS/Unicamp process the sensitivity amounted to 4,8 mV/psi with a maximum linearity of about 5,6% FSO

ASSUNTO(S)

microeletronica integrated circuits pressure sensors transdutores de pressão microelectronics pressure transducers circuitos integrados sensor de pressão

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