A transmission electron microscopy quantitative study of the growth kinetics of H platelets in Si

Proton implantation and thermal annealing of silicon result in the formatio n of a specific type of extended defects involving hydrogen, named "platele ts" or "cavities." These defects have been related to the exfoliation mecha nism on which a newly developed process to transfer thin films of silicon o nto various substrates is based. The density and the size of these platelet s depend on the implantation and annealing conditions. In this letter, rigo rous statistical methods based on transmission electron microscopy have bee n used to quantitatively study the thermal behavior of these defects. Upon annealing, it is shown that the cavities grow in size, reduce their density , while the overall volume they occupy remains constant. This phenomenon is due to a conservative ripening of the cavities. The transfer of hydrogen a toms from small to large cavities leads to a decrease of the elastic energy within the implanted layer while the strain locally increases around the p rojected range of the protons. (C) 2000 American Institute of Physics. [S00 03-6951(00)02707-8].