| 1. |
- Driussi, F., et al.
(author)
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Fabrication, characterization and modeling of strained SOI MOSFETs with very large effective mobility
- 2007
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In: ESSDERC 2007. - 9781424411238 ; , s. 315-318
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Conference paper (peer-reviewed)abstract
- Strained Silicon on insulators (sSOI) wafers with a supercritical thickness of 58 nm were produced using thin strain relaxed SiGe buffer layers, wafer bonding, selective etch back and epitaxial overgrowth. Raman spectroscopy revealed an homogeneous strain of 0.63 +/- 0.03% in the strained Si layer. Long channel n-type SOI-MOSFETs showed very large electron mobilities up to 1200 cm(2)/Vs in the strained Si devices. These values are more than two times larger than those of reference SOI n-MOSFETs. Mobility simulations with state of the art scattering models are then used to interpret the experiments.
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| 2. |
- Driussi, F., et al.
(author)
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On the electron mobility enhancement in biaxially strained Si MOSFETs
- 2008
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In: Solid-State Electronics. - : Elsevier BV. - 0038-1101 .- 1879-2405. ; 52:4, s. 498-505
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Journal article (peer-reviewed)abstract
- This paper reports a detailed experimental and simulation study of the electron mobility enhancement induced by the biaxial strain in (001) silicon MOSFETs. To this purpose, ad hoc test structures have been fabricated on strained Si films grown on different SiGe virtual substrates and the effective mobility of the electrons has been extracted. To interpret the experimental results, we performed simulations using numerical solutions of Schroedinger-Poisson equations to calculate the charge and the momentum relaxation time approximation to calculate the mobility. The mobility enhancement with respect to the unstrained Si device has been analyzed as a function of the Ge content of SiGe substrates and of the operation temperature.
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| 3. |
- Thomas, S. M., et al.
(author)
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On the role of Coulomb scattering in hafnium-silicate gated silicon n and p-channel metal-oxide-semiconductor-field-effect-transistors
- 2011
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In: Journal of Applied Physics. - : AIP Publishing. - 0021-8979 .- 1089-7550. ; 110:12, s. 124503-
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Journal article (peer-reviewed)abstract
- In this work, the impact of the local and remote Coulomb scattering mechanisms on electron and hole mobility are investigated. The effective mobilities in quasi-planar finFETs with TiN/Hf(0.4)Si(0.6)O/SiO(2) gate stacks have been measured at 300 K and 4 K. At 300 K, electron mobility is degraded below that of bulk MOSFETs in the literature, whereas hole mobility is comparable. The 4 K electron and hole mobilities have been modeled in terms of ionized impurity, local Coulomb, remote Coulomb and local roughness scattering. An existing model for remote Coulomb scattering from a polycrystalline silicon gate has been adapted to model remote Coulomb scattering from a high-kappa/SiO(2) gate stack. Subsequently, remote charge densities of 8 x 10(12) cm(-2) at the Hf(0.4)Si(0.6)O/SiO(2) interface were extracted and shown to be the dominant Coulomb scattering mechanism for both electron and hole mobilities at 4 K. Finally, a Monte Carlo simulation showed remote Coulomb scattering was responsible for the degraded 300 K electron mobility.
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| 4. |
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| 5. |
- Smith, Anderson, et al.
(author)
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Electromechanical Piezoresistive Sensing in Suspended Graphene Membranes
- 2013
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In: Nano letters (Print). - : American Chemical Society (ACS). - 1530-6984 .- 1530-6992. ; 13:7, s. 3237-3242
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Journal article (peer-reviewed)abstract
- Monolayer graphene exhibits exceptional electronic and mechanical properties, making it a very promising material for nanoelectromechanical devices. Here, we conclusively demonstrate the piezoresistive effect in graphene in a nanoelectromechanical membrane configuration that provides direct electrical readout of pressure to strain transduction. This makes it highly relevant for an important class of nanoelectromechanical system (NEMS) transducers. This demonstration is consistent with our simulations and previously reported gauge factors and simulation values. The membrane in our experiment acts as a strain gauge independent of crystallographic orientation and allows for aggressive size scalability. When compared with conventional pressure sensors, the sensors have orders of magnitude higher sensitivity per unit area.
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