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Scott E Thompson - One of the best experts on this subject based on the ideXlab platform.
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comparison between high field Piezoresistance coefficients of si metal oxide semiconductor field effect transistors and bulk si under uniaxial and biaxial stress
Journal of Applied Physics, 2008Co-Authors: Min Chu, Toshikazu Nishida, Nidhi Mohta, Scott E ThompsonAbstract:A comprehensive set of two-dimensional (2D) inversion layer Piezoresistance coefficients (π-coefficients) was measured using four-point and concentric-ring wafer bending setups on the (001) and (110) surface, ⟨110⟩ and ⟨100⟩ channel, n- and p-type silicon (Si) metal-oxide-semiconductor field-effect transistors (MOSFETs). The extracted π-coefficients, including in-plane longitudinal, transverse, and biaxial π-coefficients, are compared to the published surface Piezoresistance coefficients as well as the corresponding bulk Si values. For the (001)-oriented n-MOSFETs, the uniaxial π-coefficients depend on the applied electric field, doping density, and channel direction, while the biaxial π-coefficient has a relatively little electric field dependence. For the (001)-oriented p-MOSFETs, only the ⟨110⟩ transverse π-coefficient exhibits a strong dependence on the applied electric field. All π-coefficients for the (110)-oriented MOSFETs differ significantly from bulk Si values. A qualitative argument for the rep...
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hole mobility in silicon inversion layers stress and surface orientation
Journal of Applied Physics, 2007Co-Authors: G Sun, Toshikazu Nishida, Yongke Sun, Scott E ThompsonAbstract:Hole transport in the p-type metal-oxide-semiconductor field-effect-transistor (p-MOSFET) inversion layer under arbitrary stress, surface, and channel orientation is investigated by employing a six-band k∙p model and finite difference formalism. The Piezoresistance coefficients are calculated and measured at stresses up to 300MPa via wafer-bending experiments for stresses of technological importance: uniaxial and biaxial stresses on (001) and (110) surface oriented p-MOSFETs with ⟨110⟩ and ⟨111⟩ channels. With good agreement in the measured and calculated small stress Piezoresistance coefficients, k∙p calculations are used to give physical insights into hole mobility enhancement at large stress (∼3GPa). The results show that the maximum hole mobility is similar for (001)∕⟨110⟩, (110)∕⟨110⟩, and (110)∕⟨111⟩ p-MOSFETs under uniaxial stress, although the enhancement factor is different. Strong quantum confinement and a low density of states cause less stress-induced mobility enhancement for (110) p-MOSFETs. ...
Yongliang Yang - One of the best experts on this subject based on the ideXlab platform.
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giant Piezoresistance of p type nano thick silicon induced by interface electron trapping instead of 2d quantum confinement
Nanotechnology, 2011Co-Authors: Yongliang YangAbstract:The p-type silicon giant piezoresistive coefficient is measured in top-down fabricated nano-thickness single-crystalline-silicon strain-gauge resistors with a macro-cantilever bending experiment. For relatively thicker samples, the variation of piezoresistive coefficient in terms of silicon thickness obeys the reported 2D quantum confinement effect. For ultra-thin samples, however, the variation deviates from the quantum-effect prediction but increases the value by at least one order of magnitude (compared to the conventional Piezoresistance of bulk silicon) and the value can change its sign (e.g. from positive to negative). A stress-enhanced Si/SiO2 interface electron-trapping effect model is proposed to explain the 'abnormal' giant Piezoresistance that should be originated from the carrier-concentration change effect instead of the conventional equivalent mobility change effect for bulk silicon piezoresistors. An interface state modification experiment gives preliminary proof of our analysis.
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giant Piezoresistance of nano thick silicon induced by interface electron traping effect
International Conference on Micro Electro Mechanical Systems, 2009Co-Authors: Yongliang YangAbstract:Both n- and p-type nano-thick piezoresistors are fabricated on SOI (silicon on insulator) wafers using micro-fabrication processes. Giant Piezoresistance is measured and theoretically explained for nano-thick silicon resistors. Compared to bulk silicon, one order of magnitude higher piezoresistive coefficients are, for the first time, tested with 13nm-thick n-type and 9nm p-type samples. Surpassing 2-D quantum effect, Si-SiO2 interface electron trapping effect dominates the giant Piezoresistance. Different from equivalent mobility change in conventional Piezoresistance of bulk silicon, the giant Piezoresistance come from carrier concentration change and have the same effect on the longitudinal and transverse piezoresistors.
Rowe A. C. H. - One of the best experts on this subject based on the ideXlab platform.
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Piezoresistance in defect-engineered silicon
'American Physical Society (APS)', 2021Co-Authors: Li H., Arscott S., Thayil A., Lew C. T. K., Filoche M., Johnson B. C., Mccallum J. C., Rowe A. C. H.Abstract:The steady-state, space-charge-limited Piezoresistance (PZR) of defect-engineered, silicon-on-insulator device layers containing silicon divacancy defects changes sign as a function of applied bias. Above a punch-through voltage ($V_t$) corresponding to the onset of a space-charge-limited hole current, the longitudinal $\langle 110 \rangle$ PZR $\pi$-coefficient is $\pi \approx 65 \times 10^{-11}$~Pa$^{-1}$, similar to the value obtained in charge-neutral, p-type silicon. Below $V_t$, the mechanical stress dependence of the Shockley-Read-Hall (SRH) recombination parameters, specifically the divacancy trap energy $E_T$ which is estimated to vary by $\approx 30$~$\mu$V/MPa, yields $\pi \approx -25 \times 10^{-11}$~Pa$^{-1}$. The combination of space-charge-limited transport and defect engineering which significantly reduces SRH recombination lifetimes makes this work directly relevant to discussions of giant or anomalous PZR at small strains in nano-silicon whose characteristic dimension is larger than a few nanometers. In this limit the reduced electrostatic dimensionality lowers $V_t$ and amplifies space-charge-limited currents and efficient SRH recombination occurs via surface defects. The results reinforce the growing evidence that in steady state, electro-mechanically active defects can result in anomalous, but not giant, PZR.Comment: 9 pages, 8 figure
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Piezoresistance in Silicon and its nanostructures
'Cambridge University Press (CUP)', 2014Co-Authors: Rowe A. C. H.Abstract:Piezoresistance is the change in the electrical resistance, or more specifically the resistivity, of a solid induced by an applied mechanical stress. The origin of this effect in bulk, crystalline materials like Silicon, is principally a change in the electronic structure which leads to a modification of the charge carriers effective mass. The last few years have seen a rising interest in the piezoresistive properties of semiconductor nanostructures, motivated in large part by claims of a giant Piezoresistance effect in Silicon nanowires that is more than two orders of magnitude bigger than the known bulk effect. This review aims to present the controversy surrounding claims and counter-claims of giant Piezoresistance in Silicon nanostructures by presenting a summary of the major works carried out over the last 10 years. The main conclusions that can be drawn from the literature are that i) reproducible evidence for a giant Piezoresistance effect in un-gated Silicon nanowires is limited, ii) in gated nanowires a giant effect has been reproduced by several authors, iii) the giant effect is fundamentally different from either the bulk Silicon Piezoresistance or that due to quantum confinement in accumulation layers and heterostructures, the evidence pointing to an electrostatic origin for the Piezoresistance, iv) released nanowires tend to have slightly larger Piezoresistance coefficients than un-released nanowires, and v) insufficient work has been performed on bottom-up grown nanowires to be able to rule out a fundamental difference in their properties when compared with top-down nanowires. On the basis of this, future possible research directions are suggested.Comment: 41 pages, 4 figure
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On giant Piezoresistance effects in silicon nanowires and microwires
'American Physical Society (APS)', 2010Co-Authors: Milne J. S., Arscott S., Renner C., Rowe A. C. H.Abstract:The giant Piezoresistance (PZR) previously reported in silicon nanowires is experimentally investigated in a large number of surface depleted silicon nano- and micro-structures. The resistance is shown to vary strongly with time due to electron and hole trapping at the sample surfaces. Importantly, this time varying resistance manifests itself as an apparent giant PZR identical to that reported elsewhere. By modulating the applied stress in time, the true PZR of the structures is found to be comparable with that of bulk silicon
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Giant Room-Temperature Piezoresistance in a Metal-Silicon Hybrid Structure
'American Physical Society (APS)', 2008Co-Authors: Rowe A. C. H., Donoso-barrera A., Renner Christoph, Arscott S.Abstract:Metal-semiconductor hybrids are artificially created structures presenting novel properties not exhibited by either of the component materials alone. Here we present a giant Piezoresistance effect in a hybrid formed from silicon and aluminum. The maximum piezoresistive gage factor of 843, measured at room temperature, compares with a gage factor of -93 measured in the bulk homogeneous silicon. This Piezoresistance boost is not due to the silicon-aluminum interface, but results from a stress induced anisotropy in the silicon conductivity that acts to switch current away from the highly conductive aluminum for uniaxial tensile strains. Its magnitude is shown, via the calculation of hybrid resistivity weighting functions, to depend only on the geometrical arrangement of the component parts of the hybrid
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Giant room temperature Piezoresistance in a metal/silicon hybrid
'American Physical Society (APS)', 2008Co-Authors: Rowe A. C. H., Donoso-barrera A., Ch. Renner, Arscott S.Abstract:Metal/semiconductor hybrids are artificially created structures presenting novel properties not exhibited by either of the component materials alone. Here we present a giant Piezoresistance effect in a hybrid formed from silicon and aluminum. The maximum piezoresistive gage factor (GF) of 843, measured at room temperature, compares with a GF of -93 measured in the bulk homogeneous silicon. This Piezoresistance boost is not due to the silicon/aluminum interface, but results from a stress induced anisotropy in the silicon conductivity that acts to switch current away from the highly conductive aluminum for uniaxial tensile strains. Its magnitude is shown, via the calculation of hybrid resistivity weighting functions, to depend only on the geometrical arrangement of the component parts of the hybrid.Comment: 4 pages, 4 figures, accepted for publication in Physical Review Letter
Arscott S. - One of the best experts on this subject based on the ideXlab platform.
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Piezoresistance in nano-silicon
HAL CCSD, 2021Co-Authors: Rowe Alistair, Arscott S., Mccallum Jeffrey, Johnson Brett, Lew Christopher, Li Heng, Thayil Abel, Filoche MarcelAbstract:International audiencePiezoresistance (PZR) in nano-silicon has long promised to provide a means to sensitively transduce motion in nano-electromechanical systems. Giant or anomalous effects loosely ascribed tomechanically sensitive electronic defects have been reported in lightly doped nano-objects. On the basis of two recent works [1, 2] a quantitative description of the piezoresponse of trap-mediated, space-charge-limited transport will be given. Using silicon nano-membranes containing both native and engineered defects, it will be shown that under steady-state conditions the magnitude of the Piezoresistance is always comparable to that of charge-neutral, bulk silicon although a sign change can be induced under bipolar conditions due to stress-induced shifts in the trap activation energies. Under non-steady-state conditions, this same shift in trap activation energies can yield a giant piezoresponse at measurement frequencies close to the characteristic trapping rates. In terms of possible nano-sensing applications, the difficulties likely to be encountered when trying to exploit this giant piezo-impedance will be discussed
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Piezoresistance in defect-engineered silicon
'American Physical Society (APS)', 2021Co-Authors: Li H., Arscott S., Thayil A., Lew C. T. K., Filoche M., Johnson B. C., Mccallum J. C., Rowe A. C. H.Abstract:The steady-state, space-charge-limited Piezoresistance (PZR) of defect-engineered, silicon-on-insulator device layers containing silicon divacancy defects changes sign as a function of applied bias. Above a punch-through voltage ($V_t$) corresponding to the onset of a space-charge-limited hole current, the longitudinal $\langle 110 \rangle$ PZR $\pi$-coefficient is $\pi \approx 65 \times 10^{-11}$~Pa$^{-1}$, similar to the value obtained in charge-neutral, p-type silicon. Below $V_t$, the mechanical stress dependence of the Shockley-Read-Hall (SRH) recombination parameters, specifically the divacancy trap energy $E_T$ which is estimated to vary by $\approx 30$~$\mu$V/MPa, yields $\pi \approx -25 \times 10^{-11}$~Pa$^{-1}$. The combination of space-charge-limited transport and defect engineering which significantly reduces SRH recombination lifetimes makes this work directly relevant to discussions of giant or anomalous PZR at small strains in nano-silicon whose characteristic dimension is larger than a few nanometers. In this limit the reduced electrostatic dimensionality lowers $V_t$ and amplifies space-charge-limited currents and efficient SRH recombination occurs via surface defects. The results reinforce the growing evidence that in steady state, electro-mechanically active defects can result in anomalous, but not giant, PZR.Comment: 9 pages, 8 figure
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On giant Piezoresistance effects in silicon nanowires and microwires
'American Physical Society (APS)', 2010Co-Authors: Milne J. S., Arscott S., Renner C., Rowe A. C. H.Abstract:The giant Piezoresistance (PZR) previously reported in silicon nanowires is experimentally investigated in a large number of surface depleted silicon nano- and micro-structures. The resistance is shown to vary strongly with time due to electron and hole trapping at the sample surfaces. Importantly, this time varying resistance manifests itself as an apparent giant PZR identical to that reported elsewhere. By modulating the applied stress in time, the true PZR of the structures is found to be comparable with that of bulk silicon
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Giant Piezoresistance Effects in Silicon Nanowires and Microwires
'American Physical Society (APS)', 2010Co-Authors: Milne J.s., Arscott S., Rowe A.c.h., Renner ChristophAbstract:The giant Piezoresistance (PZR) previously reported in silicon nanowires is experimentally investigated in a large number of depleted silicon nano- and microstructures. The resistance is shown to vary strongly with time due to electron and hole trapping at the sample surfaces independent of the applied stress. Importantly, this time-varying resistance manifests itself as an apparent giant PZR identical to that reported elsewhere. By modulating the applied stress in time, the true PZR of the structures is found to be comparable with that of bulk silicon
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Giant Room-Temperature Piezoresistance in a Metal-Silicon Hybrid Structure
'American Physical Society (APS)', 2008Co-Authors: Rowe A. C. H., Donoso-barrera A., Renner Christoph, Arscott S.Abstract:Metal-semiconductor hybrids are artificially created structures presenting novel properties not exhibited by either of the component materials alone. Here we present a giant Piezoresistance effect in a hybrid formed from silicon and aluminum. The maximum piezoresistive gage factor of 843, measured at room temperature, compares with a gage factor of -93 measured in the bulk homogeneous silicon. This Piezoresistance boost is not due to the silicon-aluminum interface, but results from a stress induced anisotropy in the silicon conductivity that acts to switch current away from the highly conductive aluminum for uniaxial tensile strains. Its magnitude is shown, via the calculation of hybrid resistivity weighting functions, to depend only on the geometrical arrangement of the component parts of the hybrid
Tingkuo Kang - One of the best experts on this subject based on the ideXlab platform.
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evidence for giant Piezoresistance effect in n type silicon nanowire field effect transistors
Applied Physics Letters, 2012Co-Authors: Tingkuo KangAbstract:Experimental evidence for the giant Piezoresistance (PZR) effect in n-type silicon nanowires (SiNWs) on silicon-on-insulator wafers, also called SiNW field-effect transistors (SiNWFETs), is demonstrated. While an external mechanical strain is applied to SiNWFETs depleted by a back-gate bias, a marked increase in the subthreshold drain current is found, thus supporting the widely reported giant Piezoresistance effect. This increase can be attributed to the change in Si/SiO2 interface states, further suggesting interface trap-induced giant Piezoresistance. Furthermore, through repeated cycles of tensile and released strain, the electromechanical response of the subthreshold drain current with time offers a potential for creating strain-gated SiNWFETs.