Analysis of plate and colony precipitates decorating stacking faults in a single-crystal silicon

Publisher Website
Google Scholar
Abstract
Oxidation of silicon wafers containing lattice damage at the surface normally results in the formation of extrinsic stacking faults. Optical microscope investigation following decorative etching shows that on certain specimens the faults have a straight line appearance while on others the ends of the defect are much enlarged giving a ‘‘dog-bone’’ shape. Analytical electron microscopy investigation confirmed that the dog-bone shaped faults were decorated with two types of precipitates near their edges, colonies and plate. Both resided on the (111) fault planes and extended over several thousand angstroms. Precipitate diffraction spots were not found due to the small volume fraction, but translational Moiré fringes were observed for certain matrix g vectors, thus aiding in the crystallographic analysis. Energy dispersive x-ray analysis revealed that colony precipitates were due to Ni and Cu contamination while plate precipitates were due to Ni. Crystal structures for both were determined to be NiSi2 type silicides.