379 research outputs found
From farm to fork: Are AI and machine learning set to revolutionise the food industry?
No full textCraig Leadley and Elizabeth Sklar are giving an overview of how artificial intelligence (AI) and Machine Learning (ML) could be successfully integrated in the food industry, from traceability to, potentially, NPD.</p
Silicon–germanium interdiffusion in strained Ge/SiGe multiple quantum well structures
No full textThe corresponding author, Xue-Chao Liu, would like to apologize for the omission of some of the contributing authors from this published paper. The full list of contributing authors should read:
Xue-Chao Liu, R J H Morris, M Myronov, A Dobbie and D R Leadley
Dr R J H Morris contributed the secondary ion mass spectrometry measurement and analysis, shown in figure 2.
Drs M Myronov and A Dobbie contributed by growing the samples.</jats:p
Ohmic contacts to n-type germanium with low specific contact resistivity
No full textA low temperature nickel process has been developed that produces Ohmic contacts to n-type germanium with specific contact resistivities down to (2.3 ± 1.8) x10<sup>-7</sup> Ω-cm<sup>2</sup> for anneal temperatures of 340 degC. The low contact resistivity is attributed to the low resistivity NiGe phase which was identified using electron diffraction in a transmission electron microscope. Electrical results indicate that the linear Ohmic behaviour of the contact is attributed to quantum mechanical tunnelling through the Schottky barrier formed between the NiGe alloy and the heavily doped n-Ge.<p></p>
Long wavelength >1.9 Î1⁄4m Germanium for optoelectronics using process induced strain
No full textThe photoluminescence of tensile strained germanium nanostructures is reported. Sub-micron gratings and pillars were fabricated before being embedded in strained silicon nitride films. Using different deposition conditions and different sizes of structures, the stress in the nanostructures can be controlled. The measured optical properties of the samples show that the direct band-gap is shifted drastically towards higher wavelength to over 1.9 Î1⁄4m wavelength. This process of local control of the stress in germanium nanostructures is compatible with integrated photonic devices in waveguides geometry. This work opens the route towards emitters and photo-detectors above 1.6 Î1⁄4m wavelength integrated on silicon substrates which are not presently available. © The Electrochemical Society
Tuning the electroluminescence of n-Ge LEDs using process induced strain
No full textLEDs are reported from Ge-on-Si in which process induced strain has increased the emission wavelength. The direct bandgap electroluminescence emits up to ~ μW of power between 1.6 μm and ~1.8 μm, significantly larger than previous LEDs
Direct Band-gap Electroluminescence from Strained n-Ge Light Emmitting Diodes
No full textThe fabrication and characterisation of light emitting diode (LED) structures made of Ge grown on Si substrates is reported. The structures are circular mesa of strained n-Ge etched down to an undoped buffer of Ge. The electroluminescence exhibit average power levels at 1.7 μm of a few μW, many orders of magnitude larger than the nW previously reported. Three individual mechanisms of emission are identified which can be used to interpret the results encountered in other publications. This work potentially opens the route for integrated source of light and photodetectors above 1.6 μm on Si with applications for lab-on-a-chip and healthcare
Low specific ohmic contacts to n-type germanium using a low temperatrue NiGe process
No full textA new n-Ge Ohmic contact scheme is demonstrated using a three stage deposition of Ni, Ge and Ni. The lowest specific contact resistivity demonstrated was (1.68 +/- 0.4) x 10^-7 Ω-cm^2, with a low transfer length of (0.95 +/- 0.12) for deposited Ni and Ge annealed at 340 oC for 30 s on n-Ge with a doping density of 3 x 10^19 cm-3
On the role of Coulomb scattering in hafnium-silicate gated silicon n and p-channel metal-oxide-semiconductor-field-effect-transistors
No full textIn 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/Hf0.4Si0.6O/SiO2 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-κ/SiO2 gate stack. Subsequently, remote charge densities of 8 × 1012 cm−2 at the Hf0.4Si0.6O/SiO2 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
Strained Germanium Nanostructures on Silicon Emitting at >2.2 µm Wavelength
No full textThe photoluminescence of process-induced tensile strained nanostructures fabricated using Ge on Si is reported. 100 nm pillars were etched and embedded in a silicon nitride thin film demonstrating photoluminescence emission up to ~2.5 μm
Direct band-gap electroluminescence from strained n-doped Germanium diodes
No full textThe fabrication and characterisation of LED structures made of Ge grown on Si substrates is reported. The structures are circular mesa of strained n-Ge etched down to an undoped buffer of Ge. The electroluminescence exhibit average power levels at 1.7 μm of 10 μW, many orders of magnitude larger than the nW previously reported. 3 individual mechanisms of emission are identified which can be used to interpret the results encountered in other publications. This work potentially opens the route for integrated source of light and photodetectors above 1.6 μm on Si with applications for lab-on-a-chip and healthcare
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