Experimental measurements of grain boundary rotation toward bamboo in post-pattern annealing

The microstructure of 0.8 mu m, Al(0.5% Cu) lines has been measured both before and after post-pattern annealing in nitrogen at various times and temperatures. Grain boundary inclinations in single grain segments of lines were determined from Focused Ion Beam (FIB) images of two surfaces of the lines. The statistical distributions of inclination angles before and after annealing reveal the tendency for boundaries to rotate to reduce their area. In these experiments the rotation stagnates with the normals to the grain boundaries having a distribution of inclinations with a FWHM of about 33 degrees around the line direction.