Technology And Mechanism Study Of Preparing Silicon Oxide Graded Refractive-Index Filters And Transparent Conductive ZnO Films By Reactive Magnetron Sputtering

Optical coating technologies have been widely applied in many areas,such as scientific research,national defense,military and civilian products etc.To match the fast growing application requirements of optical communication,flat panel display etc, the performance requirements of optical coating is became more and more stringent, which issue new challenge in optical coating materials.The SiO_x and ZnO are both abundant,environmentally friendly and non-toxic new type optical coating materials,which have a wide application prospect in optical and semiconductor device industry.SiO_x materials have a wide range tunable refractive index and high transparency in infrared band,and doped ZnO has a good transparent conductive performance,make them win widespread attention.Magnetron sputtering is a widely used,mature and industrialized production technology.The two importance problem,about how to precisely and repeatedly control refractive index and thickness variation of fabricated SiO_x films,and how to suppress the resputtering effect during the sputtering process of ZnO,are crucial in applying to the industrialized production.The main purpose of this article is about a comprehensive study on the SiO_x and ZnO materials,concerning how magnetron sputtering parameters affect the chemical composition,microstructure and optical properties of deposited films.We do some research from view of application mainly about using reactive magnetron sputtering to get a steady SiO_x material with middle-refractive index and optical coating devices related,analyzing the resputtering phenomenon and the cause in the ways using radical assisted sputtering to prepare ZnO films.From plenty of experiments and careful analysis,we get the following result:1.The art to fabricate SiO_x graded refractive index material and relative SiO_x/SiO₂ multilayer infrared filters by reactive magnetron sputtering:(1) Graded refractive index SiO_x(0≦x≦2) thin film material with precisely controlled refractive index ranging from 3.69 to 1.44(@λ=1550 nm) have been obtained by changing the oxygen flow rate or sputtering power through reactive magnetron sputtering.(2) Successfully demonstrated SiO_x/SiO₂ multilayered band-pass filters and infrared reflective filters by combining the high refractive index SiO₂ and low refractive SiO_x(0≦x≦2) materials together as multilayer thin films.(3) Proved the feasibility to fabricate high quality infrared optical filters by using Si targets only,which provides a practical and economical technology for industrial fabrication.2.Theoretical and practical research on fabricating Rugate Filter by using SiO_x graded refractive index material:(1) Theoretically discussed the effect of material choice and refractive index distribution design on the optical property of rugate filter.It is shown by the experimental results that the optical property of rugate filter can by improved greatly by choosing proper refractive index amplitude modulation function and introducing refractive index matching layer on the interface.(2) Successfully manufactured high optical quality graded refractive index rugate filter by adjusting the oxygen content of the SiO_x layers.3.Research on the resputtering phenomena in radical assisted magnetron sputtering of ZnO transparent conductive film:(1) Sputtering loss mainly orients from diffused deposition and resputtering mechanisms.(2) The bombardment of negative oxygen ions on the deposited low oxide degree ZnO_x film is the main reason yielding the resputtering phenomena. The degree of reputtering is determined by the sputtering threshold of the as deposited ZnO_x film and the concentration of negative oxygen ions in sputtering zone.(3) Suggested a method to suppress the resputtering effect in ZnO film sputtering by adjusting the balance of oxygen distribution between sputtering zone and oxidation zone,provide guidance in both theory and experiment for preparing high quality ZnO transparent conductive film in future.