Julien Arcamone

Dynamic range enhancement of nonlinear nanomechanical resonant cantilevers for highly sensitive NEMS gas/mass sensor applications

This paper describes a comprehensive nonlinear multiphysics model based on the Euler–Bernoulli equation that remains valid up to large displacements in the case of electrostatically actuated nanocantilevers. This purely analytical model takes into account the fringing field effects which are significant for thin resonators. Analytical simulations show very good agreement with experimental electrical measurements of silicon nanodevices using wafer-scale nanostencil lithography (nSL), monolithically integrated with CMOS circuits. Close-form expressions of the critical amplitude are provided in order to compare the dynamic ranges of NEMS cantilevers and doubly clamped beams. This model allows designers to cancel out nonlinearities by tuning some design parameters and thus gives the possibility of driving the cantilever beyond its critical amplitude. Consequently, the sensor performance can be enhanced by being optimally driven at very large amplitude, while maintaining linear behavior.

Nanomechanical Mass Sensor for Spatially Resolved Ultrasensitive Monitoring of Deposition Rates in Stencil Lithography

Keywords: mass sensors ; nanoelectromechanical systems ; nanolithography ; nanomechanical sensors ; High-Frequency Applications ; Cmos-Mems ; Devices Reference LMIS1-ARTICLE-2009-006doi:10.1002/smll.200990007View record in Web of Science Record created on 2009-01-28, modified on 2017-05-10

A Compact and Low-Power CMOS Circuit for Fully Integrated NEMS Resonators

This brief presents a fully integrated nanoelectromechanical system (NEMS) resonator, operable at frequencies in the megahertz range, together with a compact built-in CMOS interfacing circuitry. The proposed low-power second-generation current conveyor circuit allows detailed read-out of the nanocantilever structure for either extraction of equivalent circuit models or comparative studies at different pressure and dc biasing conditions. In this sense, extensive experimental results are presented for a real mixed electromechanical system integrated through a combination of in-house standard CMOS technology and nanodevice post-processing by nanostencil lithography. The proposed read-out scheme can be easily adapted to operate the nanocantilever in closed loop operation as a stand-alone NEMS oscillator

Ultra-scaled high-frequency single-crystal Si NEMS resonators and their front-end co-integration with CMOS for high sensitivity applications

This paper reports on ultra-scaled single-crystal Si NEMS resonators (25-40 nm thick) operating in the 10-100 MHz frequency range. Their first monolithic integration at the front-end level with CMOS enables to extract the signal from background leading to possible implementation of direct/homodyne measurement, for high sensitivity sensing applications and portable systems.

Efficient capacitive transduction of high-frequency micromechanical resonators by intrinsic cancellation of parasitic feedthrough capacitances

Parasitic feedthrough capacitances represent a generic issue for capacitively transduced microelectromechanical resonators. Those parasitic capacitances degrade the output signal’s magnitude and phase by increasing the feedthrough signal and attenuating the resonance peak because of the resulting antiresonance peak. Whereas classical capacitive actuation/detection schemes only partially circumvent this issue, this work presents a specific, balanced, set-up that intrinsically cancels the effects of feedthrough capacitances. The resonator can recover its intrinsic purely RLC behavior thanks to this method which preferentially applies to given bulk modes, such as Lame for plates and elliptic for disks. It has been experimentally tested on 100 MHz plates and disks.

Dry etching for the correction of gap-induced blurring and improved pattern resolution in nanostencil lithography

We present nanostencil lithography as a new and parallel nanopatterning technique for batch fabrication of micro/ nanoelectromechanical systems (MEMS/NEMS) with high throughput and resolution. We use nanostencil lithography for the purpose of integrating nanomechanical resonators into complementary metal-oxide semiconductor (CMOS) circuits. When patterning nonflat substrates, which is the case of CMOS wafers, the gap between the nanostencil membrane and the surface induces a pattern blurring that constitutes an intrinsic limitation to the maximum achievable resolution. In our case, the lateral blurring is on the order of 150 nm on each side. We present here a remedy to this limitation that is based on a corrective dry etching step that removes the excess material and which recovers the designed pattern dimensions. As a demonstration, we succeed in the patterning of an entire 100-mm-diam wafer with nanomechanical devices having lateral dimensions in the range of 200 nm.

Dynamic stencil lithography on full wafer scale

In this paper, the authors present a breakthrough extension of the stencil lithography tool and method. In the standard stencil lithography static mode, material is deposited through apertures in a membrane (stencil) on a substrate which is clamped to the stencil. In the novel dynamic mode, the stencil is repositioned with respect to the substrate inside the vacuum chamber and its motion is synchronized with the material deposition. This can be done either in a step-and-repeat or in a continuous mode. The authors present the first results proving the accurate x-y-z in situ positioning and movement of our stages during and in between patterning.

VHF NEMS-CMOS piezoresistive resonators for advanced sensing applications

This work reports on top-down nanoelectromechanical resonators, which are among the smallest resonators listed in the literature. To overcome the fact that their electromechanical transduction is intrinsically very challenging due to their very high frequency (100 MHz) and ultimate size (each resonator is a 1.2 μm long, 100 nm wide, 20 nm thick silicon beam with 100 nm long and 30 nm wide piezoresistive lateral nanowire gauges), they have been monolithically integrated with an advanced fully depleted SOI CMOS technology. By advantageously combining the unique benefits of nanomechanics and nanoelectronics, this hybrid NEMS-CMOS device paves the way for novel breakthrough applications, such as NEMS-based mass spectrometry or hybrid NEMS/CMOS logic, which cannot be fully implemented without this association.

Fully monolithic and ultra-compact NEMS-CMOS self-oscillator based-on single-crystal silicon resonators and low-cost CMOS circuitry

We report on the first experimental demonstration of a self-oscillator based on a single-crystal silicon NEMS resonator monolithically co-integrated with a CMOS circuitry. The latter, composed only by seven transistors, is manufactured with a very low-cost 0.35μm technology. The NEMS-CMOS self-oscillator pixel is as small as 50×70 μm2 (pads excluded) and can oscillate near 8MHz. In this paper are described the NEMS-CMOS oscillator characteristics and the implementation method of the self-oscillating loop.

100 MHz oscillator based on a low polarization voltage capacitive Lamé-mode MEMS resonator

This paper describes the implementation of a 100 MHz oscillator based on a Lamé-mode MEMS resonator polarized with a low dc bias voltage (< 5 V). Under low vacuum, the MEMS resonator exhibits high quality factors up to 60000 ensuring reasonable performance in terms of measured phase noise: −100 dBc/Hz @ 1kHz from carrier. A specific capacitive actuation/detection scheme ensures an active cancellation of the feedthrough capacitances and facilitates the balance by the rack-level sustaining electronics of the equivalent 50 kΩ motional impedance (on resonance) of the 100 MHz resonator.