Highly doped zinc oxide films produced by advanced thermal processing in the millisecond range

Zinc oxide (ZnO) is an attractive candidate to replace indium tin oxide in microelectronic and photovoltaic applications. Furthermore, ZnO nanostructures hold great promise for sensor applications. Whereas n-type doping can be easily achieved, p-type doping is a more challenging issue as most defects like Zn interstitials act as n-type dopants.
In this work 100 nm thick ZnO layers were grown by atomic layer deposition on a thermal SiO2 layer on top of a Si wafer. Subsequently, the layers were implanted by phosphorus or antimony, followed by flash lamp annealing (FLA). The ZnO layers were investigated by means of Raman, photoluminescence, sheet resistance and Hall measurements. Depending on the FLA conditions, the doping type shifts from n-type dominated by defects to p-type caused by the implanted group V elements.