The Study Of Self-organization Nanostructure Formed By Low-energy Ion Beam Etching

Self-organization nanostructure is become a hot research in nanotechnology because of its novel structural features and huge potential. Low-energy ion beam erosion has been shown to be a viable route for the generation of self-organization nanostructure.In this thesis, we used AFM, SEM, non-contact surface measuring instrument and Fourier transform infrared spectrometer to characterize and test on the basis of the theory of low energy ion beam etching technology. By changing ion beam parameters of cold cathode ion source and microwave cyclotron resonance ion source, such as ion energy, ion incidence angle, ion flux and etch time, We analyzed surface topography, roughness and infrared transmittance of the etched wafer surfaces.We obtained the following conclusions after etching experiments of cold cathode ion source.1) With the increase from 800eV to 1600eV of the energy of ion beams which are 30mA in ion flux and normal in incident angle, the etched surface roughness tends to increase firstly and then decrease. When the ion energy reach to 1400eV, Self-organization nanostructures on etched surfaces are obtained, which are caused by ion beam sputter-induced roughening, and the surface roughness is increased.2) Ion beam incident energy is set up 1400eV and normal incident angle, when the beam increase from 25mA to 45mA, etching wafer surface roughness is changed; When the beam is increased to 30mA, we can see the hole shape and arrangement structure of silicon surface. At this time, roughness plays a main role and can be reached to maximum.3) Ion beam incident energy is set up 1400eV and the ion flux of ion beam is set up 30mA,when incidence angles is increased from 0°to 75°, etching silicon surface roughness is changed. When the incident angle is 45°, wafer surface plays the leading role and become smooth. That is to say. the roughness is up to minimum.4) Ion beam incident energy is 1400eV, beam is 30mA and normal incident angle, when etching time from 15 min to 90 min. surface roughness is changed. Silicon wafer surface become even of the organization point.We obtained the following conclusions after etching experiments of microwave cyclotron resonance ion source.1) Water surface is formed the organization structure when ion beam density is 300 uA/cm2, the incident angle is 5°and the incident energy is 1400eV. When the incident energy is 1000eV, wafer surface is up to the largest transmission rate, and the most large peak is 57.48% (infrared wavelength is 2.5um～5.0um).2) When ion beam incident energy is 1400eV, beam density is 300 uA/cm2 and the incident angle is 35°, we can see the etching wafer surface appear a similar blob-shaped structure. We can see the etching wafer surface become more even smooth when the incident angle is 45°, and the transmission rate is 54.70%. We can see the etching wafer surface appear cylindrical structure when the incident angle is up to 75°.At this time, the wafer surface minimum transmission rate is 50.97%(infrared wavelength for 2.5um～5.0un).