The Energy Filter Magnetron Sputtering Technology Preparation And Properties Optimization Of ITO Films

Tin doped indium oxide(ITO) is a kind of n-type semiconductor material. It has been one of the hotspot in research of materials, microelectronics and optoelectronics because of its excellent electric conductivity, high visible light through the performance, excellent mechanical properties and so on.The ITO thin films have a variety of preparation methods, such as: chemical vapor deposition method, spray pyrolysis method, vacuum evaporation method, sol-gel method, magnetron sputtering method, etc. Magnetron sputtering technology has been widely applied to various fields because it has high melting point of thin film material, high substrate adhesion, large film forming area, and good uniformity, etc. But the technology also has some shortcomings, such as in sputtering coating process, the plasma particles not only have In3 +, Sn4 +, In2O3, Sn O2, but also have O2 ˉ, O ˉ and secondary electron anion, these high-energy ion and electron will has sputtering damage on substrate and deposited thin films. In addition, the energetic particles into the film can make impurity gas mix, produce defects and the increase internal stress of the films, which has a negative impact on the performance of the film. To reduce the negative stress of thin film, we improve on the traditional DC Magnetron Sputtering(DMS) technology, and independently developed a called "Energy filter Magnetron Sputtering"(EFMS) coating technology, ITO thin films prepared by using EFMS technology have higher quality and better photoelectric properties.As solar cells, flat-panel display technology, OLED technology’s rapid development and wide application, they have higher requirements on the photoelectric properties of ITO thin films. This article mainly improves the photoelectric properties of ITO thin films by changing the process conditions, improving the preparation technology and using the TFCalc software optimization.This research were mainly divided into the following three parts:(1) Using DC magnetron sputtering technology to prepare ITO thin film on K9 glass(2.5 cm x 2.5 cm x 0.1 cm). The purity of ITO sputtering target material is 99.99%, the quality ratio of the In2O3:Sn O2 is 9:1. Using control variable method, we studied the influence of the argon ratio, substrate temperature, sputtering time, oxygen sputtering power and sputtering pressure on the properties of ITO thin film, and the influence of preparation conditions on the ITO thin film refractive index. We characterized to the thin film structure, surface morphology and optical properties(light transmittance, refractive index, extinction coefficient) and electrical performance(square resistance and resistivity) by XRD, SEM and spectrophotometer, elliptic polarization spectrometer and four point probe resistance. The results show that the preparation conditions and preparation technology have an effect on the photoelectric properties and refractive index more or less.(2) Using DC magnetron sputtering(DMS) filtering technology and Energy filter magnetron sputtering(EFMS) technology, we prepared a batch of same-thickness samples of ITO thin film respectively at room temperature and high temperature separately. We studied the effect of the two kinds of preparation technology on the properties of ITO thin film, and the influence of the two kinds of preparation technology on thin film refractive index. The results show that EFMS technology has a better photoelectric properties, and a lower index of refraction.(3)Based on the front study of ITO thin film, we found out the preparation condition and technology of lowest refractive index and highest refractive index of ITO thin film. With the condition and technology, we prepared ITO thin film samples, and measured the refractive index by elliptic polarization spectrometer, imported it into TFCalc software for optimization. We obtained the optimal preparation conditions of ITO monolayer antireflection coating and ITO homogenous double antireflection coating, and prepared the double antireflection coating under the optimal conditions, and characterized the photoelectric properties. The results show that these two kinds of the antireflection coating not only rise the average transmittance in the visible but also improve electrical properties.