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Semiconductor nanowires (NWs) attract significant attention due to their superb electrical and mechanical properties and large surface area to volume ratio. They are promising building blocks of devices for a number of possible applications such as nanoelectronics, nanophotonics, photovoltaics, sensorics, etc. Among the large variety of semiconductor NWs, the ones based on group IV elements – mainly silicon (Si), germanium (Ge) and their alloys with tin (Sn) (Si1-x-yGeySnx) – stand out because of their appealing properties and superior compatibility with the well-established silicon technology. This is an important prerequisite for their relatively easy integration into the existing semiconductor fabrication platforms. In the talk, the NWs that we work with will first be presented. These include top-down fabricated Si and Ge NWs as well as nanowires of binary and ternary Si1-x-yGeySnx alloys with varying content of the different elements. Particular attention will be paid to structural and electrical characterisation of the nanowires and especially to Hall Effect measurements using a novel six-contact Hall bar configuration with symmetric contact bars located opposite to each other. Such a configuration with narrowbars increases the precision of Hall contacts fabrication and enhances the accuracy of the Hall Effect measurement by avoiding shorting out the Hall voltage. This allows to reliably evaluate the electrical properties of even very small nanowires, down to 20-30 nm, and quantify their carrier concentration (n), Hall mobility (μH), and resistivity (ρ). The innovative nanoelectronic devices that we are targeting will also be discussed, namely junctionless nanowire transistors (JNTs) and reconfigurable field effect transistors (RFETs). We are in particular interested in Si JNTs for sensing application as well as in Ge, SiGe, GeSn and SiGeSn JNTs for digital logic. In the case of RFETs, we are currently working on Si, SiGe and GeSn RFETs and planning to work also on SiGeSn RFETs. Different configurations of such devices will be discussed together with their structural andelectrical characterisation. Additional Information: Yordan Georgiev delivered this presentation at the14th International Conference on Electron Beam Technologies. RADICAL represents a 'Fundamental Breakthrough in Detection of Atmospheric Free Radicals'. Find out more on the RADICAL project website:radical-air.eu The RADICAL project has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement number 899282. |
