Abstract:
The spontaneous self-organization of a porous surface mosaic structure in the form of islands of oxidized por-Si nanocrystallites separated by silicon ledges has been observed during prolonged anodic etching of $p$-Si (100) in electrolytes with an internal current source. The por-Si mosaic structure is spontaneously formed as a result of relaxation of an elastically strained layer of the porous surface. The self-organization of the mosaic structure of the por-Si surface, island sizes, and the period of their arrangement are controlled by a number of factors arising in the complex heterophase system electrolyte/por-Si/$c$-Si/during etching, i.e., the spatio-temporal distribution of point defects of interstitials $I_{\mathrm{Si}}$ and vacancies $V_{\mathrm{Si}}$ in the $c$-Si surface region, the formation of capillary fluctuation forces at the electrolyte/por-Si/$c$-Si/interface, the elastic deformation forces induced by the lattice parameter mismatch between the oxidized por-Si nanocrystallites and the $c$-Si matrix. The conditions responsible for the manifestation of these forces depend on the self-consistent parameters of etching of the complex heterophase electrochemical system electrolyte/por-Si/$c$-Si/with an internal current source, including the electrode characteristics and cell parameters.
Fulltext:
PDF file (2387 kB)
