Research On Remo Val Characteristics Of Radio Frequency Ion Source

With the rapid development of modern science and technology,the demand for super-smooth surface is increasing in the fields of Optics and microelectronics.At the same time,new requirements are put forward for the surface accuracy of related important components,Which need to reach the level of nanometer or even sub-nanometer.Ion beam polishing is a highly deterministic and ultra-smooth optical surface processing technology in recent years,in Which the removal characteristics are the focus and difficulty of its research.In this paper,fused quartz samples were processed by radio frequency ion source,and the removal characteristics and process parameters optimization of radio frequency ion source Were studied.The main Work and conclusions are as follows:Firstly,the working principle of ion beam polishing is expounded.The structure of radio frequency ion source and the mechanism of ion beam generation are introduced in detail.The removal theory of ion beam polishing is studied.The simulation analysis is carried out by SRIM software.It is found that the removal depth is related to the number,energy and incident angle of the incident ions.The sputtering yield expresses the sputtering ability of the incident ions and energy.The larger the incident angle is,the higher the sputtering yield first increases and then decreases,and there is an extreme value.The larger the energy of the incident ion,the larger the sputtering yield.Secondly,the removal characteristics of RF ion source are studied.It is found that with the change of working distance,the distribution of ion beam is gaussian,and the waist position of ion beam is at 60 mm.Orthogonal experiment is carried out at three factors and three levels.The influence degree of the three factors on the evaluation index of ion beam is radio frequency power > grid voltage > argon flow rate in turn.Increasing the power of radio frequency changes the alternating electromagnetic field,more power is added to plasma,the chance of gas collision increases,and the removal width decreases with increasing the power of radio frequency.The higher the grid voltage,the better the etching effect.This is because the size of the grid voltage can directly determine the number of ion beam arcing discharge and ion beam induced.The increase of gas flow rate will directly increase the chance of gas collision,resulting in the increase of ionized argon ions,and the depth of ion beam removal will also increase;the removal depth will also increase with the increase of working pressure,but the removal width will decrease with the increase of working pressure;and the removal depth will also increase with the increase of incident angle.Then,the stability of the ion source is analyzed.The parameters of RF power,working pressure and working distance are very stable for the removal characteristics,while the small perturbations of grid voltage and gas flow can not be neglected for the consistency error of the removal characteristics,and there is no good stability;neutralization analysis,filament neutralization compared with RF pulse neutralization,the removal of the ion source.The overall removal efficiency is relatively high;the relationship between the beam shape distribution of ion source and the sample removal characteristics is studied,and the variation trend of RF power is very consistent between the two.Finally,the removal function of the ion source is measured by etching experiments.The peak removal rate A of the removal function of the radio frequency ion source is 132.43 nm/min,and the distribution parameter of the Gauss function is 3.31 mm.The thermal effect of the sample surface under the action of the radio frequency ion beam is explored,and the heat source is analyzed.The surface roughness of the sample before and after etching is measured,and it is found that the ion beam etching is effective for the sample surface.Surface roughness has an effect.