Yaoling Pan

Selective processing of semiconductor nanowires by polarized visible radiation

Semiconductor nanowires have attracted intense interest due to potential applications in electronics, sensors and photonics. Introduction of dopants and their subsequent activation are essential for exploiting the electronic properties of semiconductor materials. In this work, we demonstrate pulsed laser annealing of silicon nanowires by visible radiation to be an efficient way for activating incorporated dopants and repairing implantation damage in a process that is compatible with sensitive flexible substrates. In situ electrical monitoring was used to study the laser annealing process. The absorption of laser light in SiNWs was shown to be strongly dependent on the light polarization and nanowire diameter based on finite difference time domain simulations.

Excimer laser annealing of silicon nanowires

Nanowires can potentially be used with low-cost flexible plastic substrates for applications such as large-area displays and sensor arrays. However, high temperature processing steps such as thermal annealing that are incompatible with plastic substrates are still a major hindrance. Laser annealing permits localized energy input without affecting the underlying substrate and can help overcome this problem. In this study, the excimer laser annealing of silicon nanowires is demonstrated to be an efficient means of activating implanted dopants. The optical absorption of the nanowires is discussed and the effect of parameters such as fluence and number of pulses is investigated.

Laser Thermal Processing of Nanowires

Semiconductor nanowires offer an alternative bottom-up route for nanoscale electronics and photonics application. The possibility of combining nanowires with cheap flexible substrates in the form of nanowire thin-films or composite materials composed of nanowires has opened up a new paradigm for inorganic semiconductor based technologies on flexible substrates. Recently, thin film transistors have been fabricated on plastic substrates based on this technique. This paper discusses laser thermal processing of nanowires as an alternative to conventional thermal processing. Ultra-short pulsed lasers allow for localized energy deposition into nanowires and can therefore enable thermal processing of nanowires on sensitive substrates such as plastics. Laser-based annealing of ion-implanted silicon nanowires is investigated for application in high performance flexible electronics. The efficacy of laser processing is examined through studies of the effect of number of pulses and incident fluence levels on conductance of the nanowires. Finally, numerical predictions of the absorption in the nanowires are presented.Copyright