Study On HfO₂ Thin Film By RF Magnetron Reactive Sputtering

Diamond has excellent properties such as good transmittance in the infrared wave band, low absorption coefficient, high resistance to thermal shock and friction. So diamond is an ideal material for airborne LWIR (8-12μm) windows and domes. However, diamond is easily subject to oxidation in air at temperatures greater than 750℃, and the optical transmittance is degraded greatly. It's useful to prepare anti-oxidation and anti-reflective films on the diamond surface to meet the need for applications of high-speed or high temperature environment. Hafnium oxide (HfO₂) is a promising anti-oxidation material with good physical, chemical properties and good anti-oxidation property. Some progress has been made in the researches about HfO₂ anti-oxidation films overseas. But no domestic work has been done on HfO₂ optical and protective films. Researches of the paper mostly concentrate on preparation of HfO₂ films by magnetron sputtering and the functions of experiment parameters on films components, structure, optical properties and deposition rate. The main contents and results are listed as follows:HfO₂/Diamond and HfO₂/a-Si:H//Diamond antireflection film systems are designed by OPFCAD, and the sensitive factors and deviation of the films' structure are analyzed. Results show that the average transmittance in LWIR waveband can exceed 85% after both films systems are deposited on the surfaces of diamond, which can meet the requirements high-speed infrared windows and domes.The influence of main parameters on deposition rate is discussed, and the main parameters are optimized. The results show that deposition rate of films increases with the sputtering power increasing, and decreases with sputtering pressure and O₂ flux increasing, and deposition rate is insensitive to growth temperature. The orthogonal experiment results show that the effect of O₂ flux on the deposition rates is the most significant, and the parameters to get high deposition rate are decided. XPS and XRD analyses as well as SE transmission spectrum tests are carried out.