Influence of thermal annealing ambient on Ga-doped ZnO thin films

• Published in: Journal of crystal growth 2007-12, Vol.309 (2), p.128-133
• Main Authors: Du Ahn, Byung, Hoon Oh, Sang, Hee Lee, Choong, Hee Kim, Gun, Jae Kim, Hyun, Yeol Lee, Sang
• Format: Article
• Language: English
• Subjects: A1. Adsorption; A1. Defects; A1. Desorption; A1. Doping; B2. Semiconducting II–VI materials; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Condensed matter: structure, mechanical and thermal properties; Exact sciences and technology; Optical properties and condensed-matter spectroscopy and other interactions of matter with particles and radiation; Optical properties of bulk materials and thin films; Physical properties of thin films, nonelectronic; Physics; Solid surfaces and solid-solid interfaces; Structure and morphology; thickness; Surfaces and interfaces; thin films and whiskers (structure and nonelectronic properties); Thermal stability; thermal effects; Thin film structure and morphology
• ISSN: 0022-0248; 1873-5002
• DOI: 10.1016/j.jcrysgro.2007.09.014

The effect of thermal annealing on the structural, chemical, electrical, and optical properties of Ga-doped ZnO (GZO) films was investigated in various ambients, such as oxygen, nitrogen, and forming gas (95% N 2 5% H 2). The variation of these properties is thought to be related to the chemisorption and removal of adsorbed oxygen on the GZO film surface. The carrier concentration of the GZO films increased with heat treatment in the forming gas ambient. However, the carrier concentration of the GZO films decreased with heat treatment in oxygen and nitrogen. Annealing under forming gas, oxygen weakly absorbed on the GZO film was removed. Annealing under N- and O-rich conditions, chemisorption of oxygen was dominant. These results were clarified by comparatively analyzing the chemical states of oxygen on the surface of the GZO films.