Preparation of boron-doped ZnO thin films by photo-atomic layer deposition

Low-resistivity and high-stability ZnO films were grown by photo-atomic layer deposition (photo-ALD) technique using boron as an n-type dopant. The effect of the UV-irradiation was quantitatively evaluated by controlling the intensity of the incident light. The growth mechanism of ZnO films under UV-irradiation was investigated by varying the UV-irradiation period. In addition to the UV-irradiation, n-type doping using B2H6 was carried out. By optimizing the introduction cycle of B2H6, the lowest resistivity of 6.9×10−4 Ω cm was obtained. Furthermore, ZnO films grown by photo-ALD exhibit excellent stability in the electrical properties under air exposure.