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Top-Down CMOS-NEMS Polysilicon Nanowire with Piezoresistive Transduction.

Marigó E, Sansa M, Pérez-Murano F, Uranga A, Barniol N - Sensors (Basel) (2015)

Bottom Line: The resonator made from a single polysilicon layer has a fundamental in-plane resonance at 27 MHz.Piezoresistive transduction avoids the effect of the parasitic capacitance assessing the capability to use it and enhance the CMOS-NEMS resonators towards more efficient oscillator.The displacement derived from the capacitive transduction allows to compute the gauge factor for the polysilicon material available in the CMOS technology.

View Article: PubMed Central - PubMed

Affiliation: Department of Electronics Engineering, Universitat Autònoma de Barcelona (UAB), Barcelona 08193, Spain. eloi_marigo@silterra.com.

ABSTRACT
A top-down clamped-clamped beam integrated in a CMOS technology with a cross section of 500 nm × 280 nm has been electrostatic actuated and sensed using two different transduction methods: capacitive and piezoresistive. The resonator made from a single polysilicon layer has a fundamental in-plane resonance at 27 MHz. Piezoresistive transduction avoids the effect of the parasitic capacitance assessing the capability to use it and enhance the CMOS-NEMS resonators towards more efficient oscillator. The displacement derived from the capacitive transduction allows to compute the gauge factor for the polysilicon material available in the CMOS technology.

No MeSH data available.


Piezoresistive sensing set-up with an electrostatic excitation. f will be around the first mode resonance frequency of the CMOS-NEMS CC-beam (around f = 27 MHz), and the low frequency is in our case 543 Hz.
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sensors-15-17036-f003: Piezoresistive sensing set-up with an electrostatic excitation. f will be around the first mode resonance frequency of the CMOS-NEMS CC-beam (around f = 27 MHz), and the low frequency is in our case 543 Hz.

Mentions: The set-up for piezoresistive sensing is based on a downmixing scheme using the NEMS CC beam as a mixer in order to detect its motion at low frequencies (Figure 3). This technique often called two-source, double-frequency technique has been previously used to characterize bottom-up and also top-down crystalline silicon nanowires [23]. The actuation electrode is connected to an excitation signal with a frequency, fRF, which is equally to the first lateral mode of the CC-beam. This signal along with a bias voltage VDC, induces the motion of the beam producing its resonance at fRF. This beam motion produces a change in resistance which will be at 2fRF due to the quadratic dependence of the resistance versus the displacement (piezoresistance effect, Equation (9)). In order to produce a down-mixing in the final piezoresistance current, an additional signal at 2fRF + Δf is applied directly to the CC-beam. In this way a mixing process will take place at the CC-beam, producing a piezoresistive signal proportional to the product of the signals with frequencies 2fRF and 2fRF + Δf and thus composed of several harmonics, one of which is at Δf. Finally the lock-in amplifier will detect only the component at Δf, neglecting all the others. This reference signal for the lock-in is generated through a mixer and a frequency doubler. A lock-in amplifier is used instead of the network analyzer due to the benefits of using a superheterodyne receiver where a known low frequency reference signal is multiplied by the input signal and amplified, so the scheme is capable to detect small signals even buried in noise.


Top-Down CMOS-NEMS Polysilicon Nanowire with Piezoresistive Transduction.

Marigó E, Sansa M, Pérez-Murano F, Uranga A, Barniol N - Sensors (Basel) (2015)

Piezoresistive sensing set-up with an electrostatic excitation. f will be around the first mode resonance frequency of the CMOS-NEMS CC-beam (around f = 27 MHz), and the low frequency is in our case 543 Hz.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4541920&req=5

sensors-15-17036-f003: Piezoresistive sensing set-up with an electrostatic excitation. f will be around the first mode resonance frequency of the CMOS-NEMS CC-beam (around f = 27 MHz), and the low frequency is in our case 543 Hz.
Mentions: The set-up for piezoresistive sensing is based on a downmixing scheme using the NEMS CC beam as a mixer in order to detect its motion at low frequencies (Figure 3). This technique often called two-source, double-frequency technique has been previously used to characterize bottom-up and also top-down crystalline silicon nanowires [23]. The actuation electrode is connected to an excitation signal with a frequency, fRF, which is equally to the first lateral mode of the CC-beam. This signal along with a bias voltage VDC, induces the motion of the beam producing its resonance at fRF. This beam motion produces a change in resistance which will be at 2fRF due to the quadratic dependence of the resistance versus the displacement (piezoresistance effect, Equation (9)). In order to produce a down-mixing in the final piezoresistance current, an additional signal at 2fRF + Δf is applied directly to the CC-beam. In this way a mixing process will take place at the CC-beam, producing a piezoresistive signal proportional to the product of the signals with frequencies 2fRF and 2fRF + Δf and thus composed of several harmonics, one of which is at Δf. Finally the lock-in amplifier will detect only the component at Δf, neglecting all the others. This reference signal for the lock-in is generated through a mixer and a frequency doubler. A lock-in amplifier is used instead of the network analyzer due to the benefits of using a superheterodyne receiver where a known low frequency reference signal is multiplied by the input signal and amplified, so the scheme is capable to detect small signals even buried in noise.

Bottom Line: The resonator made from a single polysilicon layer has a fundamental in-plane resonance at 27 MHz.Piezoresistive transduction avoids the effect of the parasitic capacitance assessing the capability to use it and enhance the CMOS-NEMS resonators towards more efficient oscillator.The displacement derived from the capacitive transduction allows to compute the gauge factor for the polysilicon material available in the CMOS technology.

View Article: PubMed Central - PubMed

Affiliation: Department of Electronics Engineering, Universitat Autònoma de Barcelona (UAB), Barcelona 08193, Spain. eloi_marigo@silterra.com.

ABSTRACT
A top-down clamped-clamped beam integrated in a CMOS technology with a cross section of 500 nm × 280 nm has been electrostatic actuated and sensed using two different transduction methods: capacitive and piezoresistive. The resonator made from a single polysilicon layer has a fundamental in-plane resonance at 27 MHz. Piezoresistive transduction avoids the effect of the parasitic capacitance assessing the capability to use it and enhance the CMOS-NEMS resonators towards more efficient oscillator. The displacement derived from the capacitive transduction allows to compute the gauge factor for the polysilicon material available in the CMOS technology.

No MeSH data available.