Doping issues in silicon nanowires by ion implantation and flash lamp annealing
Doping issues in silicon nanowires by ion implantation and flash lamp annealing
Berencen, Y.; Prucnal, S.; Wang, M.; Rebohle, L.; Helm, M.; Zhou, S.; Skorupa, W.
Abstract
Semiconducting nanowires (NWs) hold promises for functional nanoscale devices. Although several applications have been demonstrated in the areas of electronics, photonics and sensing, the doping of NWs remains challenging. Ion implantation is a standard doping method in top-down semiconductor industry, which offers precise control over the areal dose and depth profile as well as allows for the doping of all elements of the periodic table even beyond their equilibrium solid solubility. Yet its major disadvantage is the concurrent material damage. A subsequent annealing process is commonly used for the healing of implant damage and the electrical activation of dopants. This step, however, might lead to the out-diffusion of dopants and eventually the degradation of NWs because of the low thermal stability caused by the large surface–area-to-volume ratio.
In this work, we report on non-equilibrium processing (flash lamps) for controlled doping of drop-casted Si/SiO2 core/shell NWs with shallow- and deep-level dopants below and above their equilibrium solid solubility. The approach lies on the implantation of either shallow-level dopants, such as B and P, or deep-level dopants like Se followed by millisecond flash lamp annealing. In case of amorphization upon high-fluence implantation, recrystallization takes place via a bottom-up template-assisted solid phase epitaxy. Non-equilibrium Se concentrations lead to intermediate-band Si/SiO2 core/shell NWs that have room-temperature sub-band gap photoresponse when configured as a photoconductor device [1]. Alternatively, the formation of a cross-sectional p-n junction is demonstrated by co-implanting P and B in individual NWs at different depth along the NW core.
[1] Y. Berencén, et al. Adv. Mater. Interfaces 2018, 1800101
Keywords: doping; nanowires; semiconductor; silicon; ion implantation; flash lamp annealing
Beteiligte Forschungsanlagen
- Ionenstrahlzentrum DOI: 10.17815/jlsrf-3-159
Verknüpfte Publikationen
- DOI: 10.17815/jlsrf-3-159 is cited by this (Id 28313) publication
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Vortrag (Konferenzbeitrag)
22nd International Conference on Ion Implantation Technology, 16.-21.09.2018, Würzburg, Deutschland
Permalink: https://www.hzdr.de/publications/Publ-28313