Rapid thermal annealed Al-doped ZnO film for a UV detector

A low-resistive Al-doped ZnO (AZO) film was achieved by rapid thermal annealing. A co-sputtering method was used in the initial growth of AZO films and a rapid annealing process was performed on the as-deposited AZO film under N-2 atmosphere for 3 min. An as-deposited AZO film had an optical transmittance of 84.78% at 550 nm and a resistivity of 7.8 x 10(-3) Omega cm. A rapid annealing process significantly improved the optical transmittance and electrical resistivity of the AZO film to 99.67% and 1 x 10(-3) Omega cm, respectively. The structural changes of the AZO films were investigated by X-ray diffraction and transmission electron microscopy. The high quality AZO film was used to fabricate a metal-semiconductor-metal (MSM) structure for a UV detector. The MSM device provided a stable current of 25 mu A at a bias of 2 V in a dark condition. Under UV illumination, the MSM device was highly responsive to UV light uniformly and repeatedly, and it enhanced the current by 80% at 45 mu A. This rapid thermal annealing process may provide a useful method to fabricate quality AZO films for photoelectric applications with a low thermal budget. (C) 2010 Elsevier B.V. All rights reserved.The authors acknowledge the financial support from the Converging Research Center Program through the Ministry of Education, Science and Technology (MEST, 2010K001078) and Institute Core Research Program (NK-155B) by Korea Institute of Machinery and Materials (KIMM). Professor Wayne A. Anderson is grateful for the support through the U.S. Air Force Office of Scientific Research (FA95501010154) with Dr Kitt Reinhardt as monitor. Professor Jung-Ho Lee is thankful to the Human Resources Development of the Korea Institute of Energy Technology Evaluation and Panning (KETEP) grant funded by MEST and the financial support of the Sixth-stage Brain Korea 21 Project in 2010. Professor Junsin Yi acknowledges the support from the Korea research Council of Fundamental Science & Technology (KRCF) and Sungkyunkwan University (SKKU) for National Agenda Project Program