Study On Ion Beam Etching Mechanism Of Crystal Surfaces

With the development of science and technology, space optics components, high power lasers, X-ray optics system has gained more and more applications, at the same time integrated circuits also develop towards large-scale and ultra-large-scale, which require higher surface quality of optical element and optoelectronic element. Ion beam etching polishing as a non-contact polishing, has many advantages, therefore, it has been widely applied in the optical element and optoelectronic element to obtain high quality surface.The research is divided into two parts:ion beam etching polishing and ion beam deposition correction polishing of KDP sample. Using ion beam etching polishing technology etches quartz, ZnS and KDP sample, the influence of different ion beam process parameters on the ion beam etching polishing was investigated. Also ion beam deposition correction polishing was studied, and it was applied to polish KDP sample.(1) Ion beam etching polishing of quartz, ZnS and KDP sample. The influence of different process parameters (ion beam incident energy, ion flux density, ion beam incident angle as well as the working gas flow rate) on the ion beam etching was studied, the relationship between the evolution of the crystal surface morphology and ion beam parameters during ion beam etching, and ion beam etching mechanisms of crystal surface was revealed.(2) Ion beam deposition correction polishing of KDP sample. Firstly, the planarization layer was thinned, the ICP thinning and ion beam etching thinning was compared, choose ion beam etching to thin the planarization layer, the process parameters are as follows:ion beam incident angle of 45°, ion flux density of 354 μA/cm2, ion beam incident energy of 500eV, the flow rate in working gas of argon and oxygen of 7.2sccm and 6sccm respectively. Secondly, choose ion beam deposition correction polishing process parameters of ion beam deposition correction polishing, which needs to meet KDP and planarization layer has the same etching rate, while there is not much loss of surface morphology, the process parameters are as follows: ion beam incident angle of 45°, ion flux density of 310 μA/cm2, ion beam incident energy of 400eV, the flow rate in working gas of argon and oxygen of 12.2sccm and 1sccm respectively. Finally, using ion beam deposition correction polishing to polish KDP makes the KDP sample surface roughness reduces 0.31nm.