Formation of an antireflective structure on the surface of single-crystal silicon by accelerated Xe ions

The paper studies the effect of ion-beam etching on the reflectivity characteristics of single-crystal silicon. The surface morphology formed during ion beam treatment was investigated and it was found that at normal incidence of Xe ions on the sample surface and low ion energies, a regular pit structure is formed with an increase in the amplitude of inhomogeneities in the spatial frequency range of 0.025–0.5 μm -1 , and at grazing incidence of Xe ions and high energies, a scaly topology is formed with an increase in the amplitude of inhomogeneities in the spatial frequency range of 0.025–10 μm -1 . Based on the study, a technique for forming a developed regular structure on the surface of a polished single-crystal silicon wafer with the (110) orientation using ion-beam etching is proposed. The technique consists in irradiating the surface of a single-crystal silicon sample with a wide quasi-parallel beam of monoenergetic Xe ions. It is shown that the treatment of monocrystalline silicon with a beam of accelerated Xe ions at an ion incidence angle of 70° and an ion energy of 1000 eV for only 30 min. forms a developed relief on the sample surface, reducing reflection and providing absorption of radiation with wavelengths in the wavelength range of 400–1000 nm by more than 90%. The technique provides a decrease in the reflection coefficient greater than that of black silicon prepared by standard technology at wavelengths of 532 and 793 nm, as well as in a wider range of incidence angles at wavelengths of 532, 633 and 793 nm, which in the future will allow the manufacture of solar power plants without expensive rotary supports and reduce their operating costs.