Study On Durable Carbon-based Infrared Thin Films With Hydrogen Assisted Pulse DC Magnetron Sputtering

Infrared glass has the advantages of good light uniformity,low cost,easy processing,flexible size,good stability and so on.It can be applied to infrared weapon system,infrared imaging,infrared guidance and other fields.However,these applications are mostly used in extreme weather,such as wind,sand,rain and snow.The simple infrared glass cannot be used directly,so it is necessary to deposit the durable infrared protective film on its surface.The softening temperature of most infrared glass is relatively low,so it is of great significance to study the deposition of durable infrared protective films at low temperature.Boron carbide,germanium carbide and carbon are three kinds of widely used durability infrared materials,and have the advantages of high hardness,good stability,corrosion resistance,etc.,which are very suitable for infrared window protection film.The specific research contents are as follows:In this paper,infrared thin films were prepared by hydrogen assisted microwave plasma pulsed DC sputtering film deposition system,also known as Microdyn.This method can deposit thin films at low temperature without heating substrate,and has the advantages of high deposition rate and good quality.This paper mainly studies the influence of sputtering power,gas flow rate and other process parameters on the structure,mechanics and optical properties of Micro Dyn thin film deposition system.In the characterization of the film performance,FTIR was used to characterize the optical performance of the film,wafer geometric parameter tester to characterize the film stress,Vickers hardness tester or nano-indentation instrument to characterize the young's modulus and hardness of the film,and Raman or XRD to characterize the structure of the film.In this paper,the optical properties of the film FTIR are analyzed by using CODE software and appropriate dispersion model.Through fitting,the thickness,refractive index and extinction coefficient of the film are obtained.The following results were obtained from the study:The structures of infrared films of carbon,boron carbide and germanium carbide were amorphous.The hydrogen flow rate has great influence on the optical and mechanical properties of boron carbide films and carbon films.With the increase of hydrogen flow,the transmittance of the film increases gradually,and the extinction coefficient and refractive index decrease gradually.With the increase of hydrogen flow,the hardness,Young's modulus and membrane stress of the film all decreased.Ge target power has great influence on the optical properties of germanium carbide films when double target sputtering is used.With the increase of Ge target power,Ge volume fraction increases to 72.9% at most,film refractive index increases from 2.3 to 3.4,and extinctioncoefficients are around 0.02.The increase of Ge target power can increase hardness from9.4GPa to 10.3GPa.