Fast on-wafer electrical, mechanical, and electromechanical characterization of piezoresistive cantilever force sensors

Validation of a technological process requires an intensive characterization of the performance of the resulting devices, circuits, or systems. The technology for the fabrication of micro and nanoelectromechanical systems (MEMS and NEMS) is evolving rapidly, with new kind of device concepts for applications like sensing or harvesting are being proposed and demonstrated. However, the characterization tools and methods for these new devices are still not fully developed. Here, we present an on-wafer, highly precise, and rapid characterization method to measure the mechanical, electrical, and electromechanical properties of piezoresistive cantilevers. The setup is based on a combination of probe-card and atomic force microscopy technology, it allows accessing many devices across a wafer and it can be applied to a broad range of MEMS and NEMS. Using this setup we have characterized the performance of multiple submicron thick piezoresistive cantilever force sensors. For the best design we have obtained a force sensitivity ℜ_F = 158μV/nN, a noise of 5.8 μV (1 Hz–1 kHz) and a minimum detectable force of 37 pN with a relative standard deviation of σ_r ≈ 8%. This small value of σr, together with a high fabrication yield >95%, validates our fabrication technology. These devices are intended to be used as bio-molecular detectors for the measurement of intermolecular forces between ligand and receptor molecule pairs

Ion-sensitive field-effect transistors fabricated in a commercial CMOS technology’,

Abstract: The fabrication of pH-sensitive ISFET devices in an unmodified two-metal commercial CMOS technology (1.0 m from Atmel-ES2) is reported. The ISFET devices have a gate structure compatible with the CMOS process, with an electrically floating electrode consisting on polysilicon plus the two metals. The passivation oxynitride layer acts as the pH-sensitive material in contact with the liquid solution. The devices have shown good operating characteristics, with a 47 mV/pH response. The use of a commercial CMOS process allows the straightforward integration of signal-processing circuitry. An ISFET amplifier circuit has been integrated with the ISFET sensors

Ion-sensitive field-effect transistors fabricated in a commercial CMOS technology

The fabrication of pH-sensitive ISFET devices in an unmodified two-metal commercial CMOS technology (1.0 um from Atmel-ES2) is reported. The ISFET devices have a gate structure compatible with the CMOS process, with an electrically floating electrode consisting on polysilicon plus the two metals. The passivation oxynitride layer acts as the pH-sensitive material in contact with the liquid solution. The devices have shown good operating characteristics, with a 47 mV/pH response. The use of a commercial CMOS process allows the straightforward integration of signal-processing circuitry. An ISFET amplifier circuit has been integrated with the ISFET sensors.Peer reviewe

Resistless ion implantation of sub-micron scale features through nano-stencil

Resistless ion implantation of sub-micron scale features through nano-stenci

A Fully Integrated Electrochemical BioMEMS Fabrication Process for Cytokine Detection: Application for Heart Failure

AbstractIn this present study, a fully integrated BioMEMS was developed using silicon technology to simultaneously detect varying cytokine biomarkers: interleukin-1 (IL-1), interleukin-10 (IL-10), and interleukin-6 (IL-6) using eight gold working microelectrodes (WE). The biomarkers are one of many antigens that are secreted in acute stages of inflammation after left ventricle assisted device (LVAD) implantation for patients suffering from heart failure (HF). The monoclonal antibodies (mAb): anti-human IL-1, IL-10, and IL-6 were immobilized onto gold microelectrodes through functionalization with carboxyl diazonium, respectively. Cyclic voltammetry (CV) was applied during the microelectrode functionalization process to characterize the gold microelectrode surface properties, while electrochemical impedance spectroscopy (EIS) was used to characterize the modified gold microelectrodes. The BioMEMS was highly sensitive towards the three cytokines in a range of 1 pg/mL to 15 pg/mL, which is the window where acute inflammations were observed

Image resonance in the many-body density of states at a metal surface

The electronic properties of a semi-infinite metal surface without a bulk gap are studied by a formalism that is able to account for the continuous spectrum of the system. The density of states at the surface is calculated within the GW approximation of many-body perturbation theory. We demonstrate the presence of an unoccupied surface resonance peaked at the position of the first image state. The resonance encompasses the whole Rydberg series of image states and cannot be resolved into individual peaks. Its origin is the shift in spectral weight when many-body correlation effects are taken into account

Development of an artificial nose integrating NEMS and biological olfactory receptors

Development of an artificial nose integrating NEMS and biological olfactory receptor