Study On Discharge Characteristics Of Active Gas In Helicon Wave Plasma

Due to its special physical and chemical properties,plasma has been widely used in industry.Typical industrial applications are:plasma etching,coating,surface modification,spraying,sintering,smelting,heating,harmful treatment and so on.However,the most widely used plasma production methods are capacitive coupled plasma sources,inductive coupled plasma discharge and so on.The application of helicon wave plasma source is very few,and as a new type of high-density plasma source has aroused widespread concern in recent years.The main work of this paper involves three aspects.The first is to optimize the helicon wave plasma discharge system of the laboratory,including optimization of RF antenna cooling system,optimization of matching system,optimization of external magnetic field cooling system,optimization of gas path system.The second is based on the optimized discharge system to study the Ar/CH₄ gas discharge,firstly,the influence of RF power and magnetic field intensity on Ar/CH4 gas discharge plasma parameters?electron temperature,electron density,active group and Ion Energy?is studied,and the relationship between carbon films prepared by CH4 gas discharge and plasma parameters.Optimized RF antenna cooling and magnetic field cooling system can achieve long time?10min-45min?stable helical plasma discharge.It is found that the increase of RF power can significantly increase the electron density and electron temperature of helicon wave plasma.The electronic temperature increases from 4.25eV?300W?to 7.75eV?1500W?,and the electron density increases from 0.510 at 300W to 3.47 10 at 1500W.The emission intensity of argon atom and argon ion spectral line increases with the increase of RF power,and the increase of RF power increases the energy of ions.The density of plasma increases with the increase of magnetic field strength.The emission spectrum diagnosis shows that the content of the material?CH??H Balmer series??in the plasma tends to saturate as the magnetic field increases to 2074 Gs.The results of mass spectrometry diagnosis show that there are unstable phenomena in long time Ar/CH₄ plasma discharge under different magnetic field intensities.We find that the Ar/CH₄ helicon wave plasma discharge is relatively stable when the magnetic field strength is 1841 Gs,which is beneficial to the growth of carbon films.