Epitaxial lateral overgrowth of Si on (1 0 0)Si substrates by liquid-phase epitaxy

Abstract

We have grown epitaxial silicon layers by liquid-phase epitaxy on (1 0 0) oriented, oxidised silicon substrates containing various line-seed patterns. For the case where single, unconnected line seeds are used, the amount of growth out of the lines is limited and the epilayer displays a triangular shape in cross section. However, when a mesh pattern is used, the presence of continuous sources of atomic steps at the interSections of the seeding lines leads to the growth of thick epitaxial layers displaying a diamond shape in cross section. By orienting the grid so that the seeding lines are aligned approximately 20° off the 〈1 1 0〉 directions, layers with nearly uniform thickness have been obtained. The epitaxial structures can be detached from the substrate, to allow its re-use for the growth of a subsequent epilayer. Due to their high crystalline quality, the epilayers are particularly suitable for solar cell applications.