Annealing Textures of Thin Films and Copper Interconnects

摘要

Vapor-, electro-, and electroless-deposits have usually strong fiber textures. When annealed, the deposits undergo recrystallization or abnormal grain growth to reduce their energy stored during deposition. The driving force for recrystallization is mainly caused by dislocations, whereas that for abnormal grain growth is due to the grain boundary, surface, interface, and strain energies. During recrystallization and abnormal grain growth, the texture change can take place. The recrystallization and abnormal grain growth textures are in general of fiber type. However, copper interconnects are subjected to non-planar stress state due to geometric constraints during room temperature and/or elevated temperature annealing. The annealing textures of the thin films and copper interconnects are discussed in terms of the minimization of the surface, interface, and strain energies, the grain boundary energy and mobility, and the strain-energy-release maximization.