The Impact Of Irradiation Of Optical Materials At Far-infrared And Ultraviolet Waveband

Single crystal silicon is an important material used for semiconductor devices and also a potential material in device research. In this thesis, the single crystal silicon samples are implanted by helium ions and nitrogen ions, irradiated by γ irradiations with different doses, and coated by Ag films with different thicknesses. The optical properties and surface morphology of the silicon based samples are studied. The experimental results would be helpful for the research of properties of single crystal silicon. The main contents are as follows:(1) The single crystal silicon samples are implanted by helium ions with different doses. The absorption coefficients and refractive indices of silicon samples with different helium concentrations are measured at the temperature range from 145 K to 520 K. The results show that the absorption coefficient increases with the increasing dose of helium ions, but the refractive index decreases. The correlations between absorption coefficients and refractive indices and temperature of all samples are similar. The refractive index increases with temperature in the whole measurement temperature range, but the absorption coefficient has the different trend in the different waveband. The absorption coefficient decreases with the increase of temperature when the wave number is less than 12 cm-1. However, the absorption coefficient increases when the wave number is more than 30 cm-1. The absorption coefficient curves at different wavebands are calculated by using the Drude model a nd the experimental results coincide with the calculated ones. The roughness increases with the increasing dose of helium ions measured by an atomic force microscope. There are some hills at the dose of 2.0×1017 cm-2. Both absorption coefficient and luminescence intensity of samples and density of He bubbles increase with the increasing dose of helium ions. The spalling of sample surface occurs when the dose is 4.0×1017 cm-2. There are some new peaks occurred at 360 nm, 407 nm, 537 nm and 600 nm, respectively, when the dose is 1×1017 cm-2.(2) The properties of Ag films with different thicknesses are studied. The roughness, particle size and absorption coefficient increase with the increasing thickness.(3) The single crystal silicon and SiO2/Si samples are implanted by nitrogen ions with different doses. The absorption coefficient, transmittance, refractive index and dielectric constant of Si have little change and the roughness increases with the increasing dose of N ions. The transmittance of SiO2/Si samples has little change with increasing dose of N ions, but the roughness first decreases and then increases.(4)The single crystal silicon and SiO2/Si samples are irradiated by Co60 γ-ray with different doses. The damage become serious and the absorption coefficient and intensity increase with the increasing doses. There is no new peak appeared in the samples. The damage of SiO2/Si samples become serious and the refractive index has little change with the increasing dose.