Correlation between special grain boundaries and electromigration behavior of aluminum thin films

Abstract

The texture in thin films develops during processing steps such as deposition and annealing. Recent studies show that texture plays an important role in stress voiding, thermal hillock formation, grain collapse and electromigration failure. Specifically, electromigration failure depends on the grain misorientation distribution, which describes the probability of different grain boundaries and, therefore, links the grain boundary structure to the mass transport that takes place primarily along the grain boundaries. To understand the relationship between the grain misorientation and electromigration lifetime in aluminum thin films, the texture was measured on three sets of films from different manufacturing conditions. The frequency of occurrence of coincidence site lattice (CSL) grain boundaries, which represent special misorientations between grains, was obtained, and electromigration tests were done for all three conditions. Experimental results show that the lifetime of patterned films increases as the amount of 111 texture and the frequency of CSL boundaries increased. © 1995, Canadian Institute of Mining and Metallurgy. All rights reserved.