Prepartion Of ATO Thin Films By APCVD And Study On The Effects Of Technological Parameters On Structure And Properties Of Thin Films

In this paper a comprehensive introduction of low emissivity (low-E) coatingglass has been given including the development, energy saving characteristic, typesand preparation methods. It shows that antimony doped tin dioxide thin film haspromising prospect as the material of low emissivity coating glass because of itsexcellent optical and electric conductivity properties and cheap cost and easiness tohandle.Based on the process flow and equipment of the floating glasses on-line CVD,we designed the gasification equipment,the reactor and the premix equipment byourselves.Using the equipment system which we put up and using metal saltsSnCl₂·2H₂O and SbCl₃ as Precursors, antimony-doped tin oxide films with goodoptical and electrical properties have been deposited on soda-lime glass with SiO₂coated by APCVD method.The sheet resistance can reach as low as 62Ω/â–¡underoptimum deposition conditions(substrate temperature:525℃,substrate conveyingspeed:5mm/s, Sb/(Sn+Sb) atomic ratio:3%,flow rate of N2:3.5m3/h,deposited 8times).The visible transmission is about 82% with Infrared reflection about 56%.It has been found that the substrate temperature, substrate conveying speed, flowrate of N₂, heat-treatment temperature have strong influence on the structure andcomposition of SnO₂ films. The SnO₂ crystals exist as tetragonal rutile structure byAPCVD method. With the substrate temperature increasing the crystal structure tendstoward integrity, the ionic valence state of Sb on the surface of the films is Sb⁵⁺.While the substrate temperature is at 530℃, the carbon is not burn out and exists inthe form of C-O group in the film. A change of preferred orientation from (110) to(200) with the increase of substrate conveying speed was observed.But after the filmhas been treated, the preferred orientation changed from(200) to(110). The preferredorientation of the film at (110) is benefit to its infrared reflectance. The flow rate ofN2 play an important role on morphology of the films. The morphology changed fromsmoothness to having many small holes with an increase of the gas flow.