Formation of porous silicon by nanopowder sintering

The technique of the electrochemical and photoelectrochemical etching of single-crystal silicon wafers commonly used to fabricate macroporous silicon layers is inefficient and costly. An alternative method for forming bulk macroporous silicon is the high-temperature sintering of Si powder. The process of nanopowder sintering preliminarily subjected to dry cold compression (without binding additives) is investigated. The properties of the sintered material, including its microstructure, density, and electrical conductivity, are studied at different annealing temperature and time. Techniques for changing the porosity of the sintered samples and for determining of the interior surface area are discussed.