Dislocations induced by boron diffusion in silicon: A transmission electron microscopy study

摘要

The misfit dislocations that are introduced into silicon (001), (111) and (110) wafers by boron diffusion are found to nucleated from the diffusion surface as half-loops with Burgers vectors inclined to the surface. The expansion of the dislocation half-loop on its glide plane leaves a 60 degrees misfit dislocation in the diffusion front. Numerous dislocation reaction products which are the results of the interation among the half-loops during their expansion are characterized by cross-section and plan-view transmission electron microscopy. The dislocations with density of the order of 10(8) cm(-2) are distributed mainly in the region that is in a certain depth below the surface, leaving the top region basically dislocation free. The misfit dislocations that are nucleated from surface are not enough to relax all the strain in the diffused layer.