Nanostructuring Surfaces of HgCdTe by Ion Bombardment

Abstract

Presented in this work are the results concerning formation of nanoscale patterns on the surface of a ternary compound. The evolution of surface morphology of (111) Hg_1–xCd_xTe (х ∼ 0.223) epilayers due to ion irradiation in the energy range 100–140 keV was studied. Modification was performed using the method of normal- (θ = 0°) and oblique-incidence (θ = 45°) ion bombardment. We have shown that in the range of nanoscale, arrays of holes and mounds on (111) Hg_1–xCd_xTe surface have been fabricated using B⁺ and Ag⁺ ion beam irradiation, respectively. In addition, after normal-incidence irradiation with Ag⁺ ions, a uniform array of nano-islands 5–25 nm in height was obtained, while the topometry investigation after oblique-incidence irradiation with Ag⁺ ions points to the structures with fractal geometry. Processing of Hg_1–xCd_xTe films with ions of different radiuses leads to the formation of surface layers which are significantly different in thickness (400 nm and 100 nm for B ⁺ and Ag ⁺, respectively), as well as with maximum mechanical stresses that differ by two orders of magnitude (1.4 × 10³ Pa and 2.2 × 10⁵ Pa, respectively). The role of ion beam sputtering and deformation fields appearing upon implantation of ternary compound is discussed in the framework of existing models of surface patterning.