Pattern Evolution And Performance Analysis Of Micro-Nano Structure Irradiated By Ion Beam

The research on functional surfaces of micro-nano structures is a hot topic in the field of surface engineering.In this paper,by constructing micro-nano structures on the surface of fused silicon,which can effectively improv the surface transmittance and wettability and expand its application in the field of long-wave infrared.In this paper,the geometric parameters of the micro-nano structures on the silicon surface were designed based on the thin film anti-reflection theory and the equivalent medium theory.,and then optical models of the above structures,which were established and simulated by finite element simulation.Based on the wettability theory,a mathematical model was established.By means of radical plasma source(Radical Plasma Source,RPS)etching technology and low-energy ion beam etching technology,the preparation of micro-nano composite structure with both antireflection and hydrophobic functions was completed on the silicon surface.The specific research contents were as follows:(1)The model of the micro-nano structure was established by finite element simulation,and the law of the optical performance of different topography and geometric parameters(period,height,duty cycle)changing with the geometric parameters were studied.The simulation results showed that the period of the microstructure was an important factor to realize the antireflection effect;when the period and height of the microstructure were fixed,the antireflection effect of a certain band could be achieved by adjusting the height of the microstructures;the antireflection effect of the trapezoidal microstructure was better than that of the conical and square columnar microstructures;nanostructures had no obvious antireflection effect in the infrared band.In terms of the antireflection effect,the influence of microstructures on the transmittance was dominant,and nanostructures basically had no great influence on the transmittance.A mathematical model of wettability was established,and the geometric parameters of the microstructures affected its wettability.The following conclusions were drawn: the contact angle of microstructures decreased with the increase of the period,and the contact angle of the microstructure increased with the increase of the height,the contact angle of the microstructure decreased with increasing duty cycle.(2)RPS etching technology was used to prepare microstructures on the silicon surface with photoresist mask,and the effect of etching time on the microstructure of silicon surface was systematically studied,and the evolution characteristics of the geometric size of microstructures with time and the fabrication process parameters of the microstructure were obtained..The law of influence of microstructure height and period on contact angle was obtained.The results showed that when other process parameters were fixed,with the increase of etching time,the height of the microstructures was larger,the sidewall angle of the microstructure was basically unchanged,the width of the bottom of the microstructure tended to decrease,and the period of the microstructure was basically unchangded.(3)Nanostructures were prepared on the silicon surface by low-energy ion beam etching technology.The evolution law of the nanostructures on the silicon surface with different ion beam currents,ion beam energy and incident angle were mainly studied,and the preparation parameters of high aspect ratio nanostructures were obtained.The results showed that with the increase of the ion beam current could improve the height and orderness of its nanostructures to a certain extent.By increasing the incident angle of the ion beam,the height of the nanostructure showed an increasing trend,and the faceted structure gradually appeared.(4)On the basis of microstructures and nanostructures experiments,the preparation experiment of micro-nano composited structures were carried out,and the transmittance and wettability test of micro-structures,nano-structures and micro-nano composited structures were carried out.The results showed that the contact angle of the micro-nano composite structures was larer than only with the microstructures and nanostructures,which indicated that the existence of the micro-nano structure could improve the hydrophobicity of the silicon surface;the transmittance of the micro-nano composited structures was slightly larger than the transmittance of microstructures.In the infrared band,the microstructures played a dominant role in realization of the antireflection function,and the nanostructures basically had no antireflection effect,which verified the effectiveness of the simulation analysis at the same time.