Various structures of macroporous silicon intended for the fabrication of lithium ion battery anodes have been studied. Macroporous membranes were prepared by the photoelectrochemical etching of n-type silicon wafers possessing various resistances, followed by the removal of the substrate. The porosity was increased via additional oxidation with the subsequent etching of oxide. The electric contacts on the membrane were fabricated by depositing copper with a titanium sublayer and soldering the structure to a supporting molybdenum disk. The electrochemical characteristics of anodes were studied in a cell with a lithium counterelectrode. These measurements showed that the obtained porous silicon electrodes possess a high capacity for lithium insertion (up to 50 mAh/cm²) and admit more than 20 charge/discharge cycles.

Joint electrochemical etching of deep macropores and trenches in n-Si (100) has been studied. After the substrate was removed, regions of a sample, bounded on all sides by a closed contour of through trenches, were extracted from the sample, with narrow bars of a 2D photonic crystal remaining. The influence exerted by the distance between pores and a trench and by the modes of etching and subsequent oxidation on the roughness of the side walls of the structures and also on the size and shape of pores near the trench is analyzed for the example of a photonic crystal with a square lattice of macropores. Conditions are found in which the lattice distortion of the photonic crystal is at a minimum and the side walls of the structure are the smoothest (root-mean-square roughness height ∼60 nm).

The conditions under which quartz microtubes 5–10 µm in diameter are formed in the course of structuring oxidized macroporous silicon are reported. It is shown that microtubes with a closed bottom can be fixed in a vertical position at equal distances from one another in correspondence with the “lattice” of macroporous silicon and may be of interest as test tubes for a single-chip microlaboratory. In a disordered state, long, thin quartz microtubes form a “glass wool.” It is found that the microtubes and the glass wool exhibit high-intensity photo-and cathodoluminescence with the highest intensity in the green spectral range.

A new technological process for fabricating structures with vertical walls in a thick layer of macroporous silicon on a substrate is reported. The problem of photolithography has been solved by patterning on the back side of the wafer. As a result, the silicon substrate itself serves as a mask through which certain parts of the porous layer are removed. Narrow and high bars of macroporous silicon, aligned with macropore rows, have been fabricated. The 2D photonic crystals obtained have been used for in-coupling of light in the direction perpendicular to the channel axes and for recording IR spectra.