Annealing Effect on Lattice Distortion in Anodized Porous Silicon Layers

Abstract

The annealing effect on the lattice distortion of porous silicon (PS) layers have been studied mainly by X-ray multiple-crystal diffractometry and infrared spectroscopy. The lattice spacing of PS layers changed with increasing annealing temperature and finally became smaller than that of the unanodized Si substrate above 350°C. The lattice contraction of PS layers was found to be strongly related to the desorption of hydrogen atoms from the PS layer. It is also shown that the lattice expansion of as-prepared PS layers is attributable to hydrogen atoms chemisorbed on the pore surfaces in the PS layer.