Design And Optimization Of Spatial Separated Atomic Layer Deposition System

Atomic layer deposition（ALD）is a technique of thin-film growth that can be controlled by nanoscale precision.For conventional temporal ALD,the growth rate is relatively slow and the size of the device is limited.Therefore the development of the industry is limited.Spatial Atomic Layer Deposition（S-ALD）is a kind of thin film growth technology based on ALD technology.Compared with the traditional atomic layer deposition technology,the spatial atomic layer deposition technology has a high throughput,large scale,which can realize continuous production,and even can be applied to the characteristics of flexible substrate.This paper focuses on the design and construction of a spatial atomic layer deposition system,and explores process conditions of thin film growth and the optimization design of this system.The main contents of the work include the following aspects:（1）Based on the theory of spatial atomic layer deposition,an S-ALD system is designed and built.The atomic layer deposition experiment is carried out on the self-built system to explore the process conditions of the atomic deposition technique.The optimum experimental parameters of the system are obtained through the experimental study of the flux of precursors,the flow rate of the isolated gas,the deposition temperature,the distance of the gap and the velocity of the substrate.（2）The S-ALD design is optimized through analyzing the problems in the experiment and finding out the shortcomings of the S-ALD system.The main optimization includes:the size and structure of the nozzle are redesigned to achieve a large scale film deposition and more uniform gas distribution;a more accurate lifting platform is used to obtain more accurate clearance distance;the use of linear motor to drive the movement of the substrate to obtain faster movement speed and less vibration;the sealed box is used to reduce the open environment of water and oxygen during the film deposition and get high quality films.（3）ZnO/TiO₂ nanostructured thin films are deposited by our self-built S-ALD system.The deposition process of ZnO/TiO₂ nanolaminates is investigated,and the ZnO/TiO₂nanolaminates are deposited under the optimum conditions.Characterizations and analyses of the microstructures,surface morphology,optical properties and electrical properties for the samples are tested by transmission electron microscopy（TEM）,X-ray diffraction（XRD）,atomic force microscopy（AFM）,ellipsometer,UV/VIS spectrometer and Hall effect tester.