The Effect of Fine Channel & Collisional Mixing on Mist CVD Method
Toshiyuki KAWAHARAMURA
Abstract:The mist CVD method, previously named as mist deposition or spray pyrolysis, is an environmental friendly and cost-effective technology for the deposition of thin oxide films. The mist CVD method features the liquid solution of constituent elements as source materials, which is atomized to form the mist of aerosol particles. The mists are then transferred by a carrier gas to the reaction area to the deposition of thin films. This does not need vacuum systems because it is operated at atmospheric conditions. Furthermore various material solutions are chosen for the source, including innocuous and nonpoisonous ones. Therefore, this method possesses advantages of safety, cost-effective, light load to the environment, harmless to the human, and multiplicity of applying to a lot of materials. And in order to make smoother films on large substrates in this technology, it is important to obtain the uniform flow of mists and carrier gas. We develop two kind of new methods. One of them is named as fine channel mist chemical vapor deposition (FCM-CVD) method which has a fine channel and collisional mixing to obtain uniform flow of mists and carrier gas. The other is named as linear source mist (LSM-) CVD method which is a technique for specializing in a continuous process. With using FCM-CVD, we fabricate ZnO thin films and succeed to obtain the homogeneous thin films on the 100 mm square glass substrate whose deviation rate is } 0.45 % at 40mm2. In this study, we reported the effect of gFine channelh and gcollisional mixingh on mist CVD method from view points of theorem, simulation, experience, and so on. Key Words:Mist CVD, Mist deposition, Spray pyrolysis, ZnO, Zinc acetate, Ultrasonic formation of mist, Fine-channel, Micro-channel, Transparent conductive thin films, Homogeneous thin film, Computational fluid dynamics, The uniform flow of mists