Study of inductively coupled plasma effects for ZO:N thin films

ZnO has been considered in various industrial applications owing to its piezoelectric properties and wide band gap of near ultraviolet. However, its application to optoelectronic and display devices is still very limited due to the difficulty in obtaining good and stable p-type ZnO. In order to study p-type ZnO (ZO:N), we developed a plasma enhanced atomic layer deposition (PEALD) system adopting an inductively coupled plasma (ICP) source; its plasma generation was carried out and ZnO thin films were fabricated using both PEALD and ALD process. Diethylzinc was used as a zinc precursor, H₂O as an oxidant, nitrogen as a dopant, and argon as a carrier and purge gas. Self-limiting growth and doping effects were investigated at various flow rates, reaction times and radio-frequency powers. The properties of thin films were investigated using field emission scanning electron microscopy (FESEM), Auger electron spectroscopy (AES), Hall measurement, photoluminescence measurement (PL), X-ray diffraction (XRD), etc. Detailed results will be presented.