Deposition Of ZnO And Al Doped ZnO Films By Magnetron Sputtering And Fabrication Of MSM Ultraviolet Photodetector

Wide band semiconductors has been greatly developed with ultraviolet photodetectors applied more and more widely in many aeras. ZnO, as a direct and wide band gap semiconductor, has promising applications on optoelectronic devices. In recent years ZnO has been a hotspot in the area of semiconductor optoelectronic material. At present, high quality ZnO film is grown on sappire by MOCVD or MBE, which is expensive and limits potential applications of ZnO material. Magnetron sputtering is a simple technique which has been widely applied on film deposition. It is cheap and has a good compatibility with integrate circuit technology. It is a very significant task that high quality ZnO film is prepared by adjusting the technology parameters of magnetron sputtering. ZnO is resistant to high energy proton irradiation, which makes it have particular advantages over other wide gap semiconductors on fabrication of ultraviolet photodetector. In this dissertation, high quality ZnO and AZO films were deposited on SiO₂/Si and quartz glass substrates by RF magnetron sputtering. Based on the study of the films, MSM structure ultraviolet photodetects were fabricated on ZnO films on SiO₂/Si substrate. The work is of a great significance in application of ZnO film on optoelectronic devices. The main contents of this dissertation are summarized as follow:The ZnO and AZO films with c-axis preferred orientation were deposited on SiO₂/Si and quartz glass substrates by RF magnetron sputtering. The effects of sputtering parameters on the properties of the films were investigated by XRD, AFM, SEM, Hall effect and transmission spectra. The ZnO and AZO films on SiO₂/Si under better sputtering parameters were annealed. The quality of the films was improved with annealing temperature raising.Ag-ZnO-Al and Au-ZnO-Al quadrate structures were fabricated on the ZnO films on SiO₂/Si annealed at 900℃. The results indicate that schottky contact is achieved by Ag-ZnO contact and ohmic contact is achieved by Au-ZnO contact. Ag-ZnO-Ag and Au-ZnO-Au MSM photodetectors were fabricated on the annealed ZnO films on SiO₂/Si. Metal electrodes were achieved by a lift-off process. I-V, C-V and photoresponsivity characteristics of the photodetectors were analyzed. The photoresponsivity was high in the ultraviolet range and exhibited a maximum value around 370nm.In the dissertation, A lot of experiments and theory research have been conducted. Some technical problems are solved innovatively: The compact ZnO and AZO films with c-axis preferred orientation and uniform grains were deposited on SiO₂/Si and quartz glass substrates by RF magnetron sputtering; We discussed ZnO film growth process by ZnO film growth model and cross section image of the ZnO sample; The effects of sputtering parameters and annealing on the properties of the films were investigated; Optical band gap of the AZO films was analyzed by Burstein-Moss effect; Ag-ZnO-Ag MSM schottky photodetectors and Au-ZnO-Au MSM Photoconductive detectors were designed and fabricated.