Atmospheric Pressure Synthesis Of SiO₂ Thin Film And Composition Interpretation Of Aluminosilicate Glass

Silicon dioxide（SiO₂）film and SiO₂-based glass are the important components of silicon-based oxide,which are of great practical significance for the discipline theory,industry prospect,social development and national economy.SiO₂ thin films are widely used in sensors,semiconductor devices,microelectronics and integrated circuits,optoelectronics,optical devices and any other fields due to the excellent properties.However,the application of SiO₂ as an insulating film is limited by the following factors.Firstly,the resistivity is even lower than 10⁵?as the thickness of SiO₂ film is reduced to micron level.Secondly,the high vacuum condition in SiO₂ thin film preparation is usually lower than～10^-1 Pa.Thirdly,it is difficult to prepare on substrates with large size and/or complex surface morphology because the sample size is limited by the size of preparation equipment and method.The above factors limit the SiO₂ thin films preparation on substrates of large size and/or complex surface morphology at atmospheric pressure.In addition,SiO₂ has excellent physical and chemical properties determined by its network structure so that it has been widely used as the main raw material for making glass since ancient times.Aluminosilicate glass is often used as cover glass because of its excellent mechanical properties and toughening properties.However,on the basis of SiO₂,there are many kinds of dopable elements and wide range of doping amount,which lead to many difficulties in glass composition design and industrial production.Most glass components are determined through long-term production experience and engineering practice.Even though researchers have established and developed many semi-empirical models in order to explore the components of glass,they all have their own defects.In order to solve the above problems,the following work is carried out in this paper:（1）Atmospheric pressure plasma jet（APPJ）technique was used to prepare SiO₂ film on the surface of FTO.The effects of discharge voltage on the insulation resistance of SiO₂ films were studied systematically.XRD,TEM,SEM results show that the chemical composition,crystal structure,and surface morphology of SiO₂ films have little influence on the insulation resisitance of SiO₂ films.The OES result shows that the collision between Ar*and HMDSO produces more Si⁴⁺with the increase of discharge voltage,and Si⁴⁺rapidly combines with e to form Si.In addition,oxygen molecules dissociate into oxygen atoms with less energy required.Excessive Si atoms consume more oxygen atoms per unit time,and more Si-O bonds can be formed on the growth surface of SiO₂ films,which lead to the increase of insulation resistance.Through the stepping motor system,the fibrous structure can be avoided in the film growth process,and then the insulation resistance of the film can be improved.（2）APPJ technique was used to prepare SiO₂ film on the outer surface of 304 stainless steel pipe.The effects of APPJ scanning mode,pipe diameter and surface roughness on the insulation resistance of SiO₂ film were studied systematically.Series studies show that the densification and insulation resistance of SiO₂ films can be effectively improved if APPJ is always parallel to the normal direction of the outer surface of 304-SSPs.In case of radii and surface roughness of 304-SSPs in the range 9～16 mm and 0.1～1.0μm,the calculated results show that the negative influence on insulation resistance of SiO₂ films is lower than 0.5,which could be neglected.While,the ratio of 304-SSP diameter to APPJ tube diammeter is about 5:1,SiO₂ film has the best insulation performance.This experiment also proves the feasibility of using APPJ technology to prepare thin film on the surface of complex shape workpiece.（3）The cluster plus glue atom（CPGA）model is used to analyze the composition of commercial aluminosilicate glass,summarize the rules,and predict the composition of the next generation aluminosilicate glass.Through the determination of the composition of the existing six generations of glass,it is found that the values obtained by CPGA model are in good agreement with the measured results for MC²⁺,MC³⁺and MC⁵⁺,which indicates the feasibility and availability of CPGA model in the field of aluminosilicate glass.As a whole,from generation 1 to 6,the sum of MC⁺in CPGA model fluctuates between 10.65 and 11.58,which can be set as the constant 11.The quantity of MC²⁺gradually decreased from 4 to 1.At the same time,the quantity of MC³⁺increased from 4 to 10.Then,based on CPGA model,the composition units of next generation aluminosilicate glass are designed,which could further improve MC³⁺content from 10 to the ultimate goal 12.With the guidance of CPGA model,the aluminosilicate glass enterprise,as well as other kinds of glass enterprise,could avoid the huge research and development costs,as well long time.