Research And Application Of Novel Anode Layer Ion Source

As a cathode gas ion source with high ion beam current and simple structure,anode layer ion source has been widely used in ion beam assisted deposition,substrate cleaning and film deposition process,etc.Furthermore,its prepared diamond-like coatings(DLC)have low internal stress and excellent tribological properties.However,contamination occurs on anode surface after a long period of operation,resulting in reduce discharge stability and coating defects.In view of above problems,this project developed a new anode layer ion source through the improvement of gas input path and electrode structure.The anode pollution is greatly reduced and this equipment can sustain long-term stable work with excellent DLC performance,which basically eliminates defects such as particles.Firstly,PIC/MCC method programmed by Matlab software was used to simulate the discharge process and plasma distribution of the anode layer ion source.The simulation results indicated that the plasma was cut into two parts due to the uneven electromagnetic coupling field.One part diffuses outward producing an output beam.The other portion deposites directly on anode surface or the bottom of inner cathode and forms contaminations because of the particles are carbonized at the discharge temperature.As the pollution accumulated,the gas flow blows it into the vacuum chamber.To solve this problem,the internal gas path and electrode structure of the ion source were redesigned by Solidworks software.The effects of gas path and cathode position on plasma discharge and distribution were studied.It was found that the solid cathode with tip structure and raised by 6 mm can obtain the best particle distribution and achieve the highest ionization intensity and diffusion at 1 Pa of working pressure.Furthermore,venting from the inside of the anode allowed the reaction gas enter the plasma region directly,the pollution of anode surface and the effect of airflow to the contaminated attachments are greatly reduced.Finally,ultra-thick DLC coating was prepared by the novel anode layer ion source.The results reveal that the novel anode layer ion source has a higher discharge intensity and a better working stability.The contamination was greatly reduced within 8 hours of deposition time.The defects of the prepared DLC coating are substantially eliminated.The hardness,adhesion values,tribological properties and especially the corrosion resistance are significantly improved.