Stress evolution in the metal layers of TSVs with Bosch scallops
We have studied the stress evolution in the tungsten film of a particular open TSV technology during the thermal processing cycle. The film is attached to the via’s wall, where scallops were observed as a result of the Bosch processing. Our work describes a scheme which considers the scallops on the TSV and conjugates a stress model for thin-films with the traditional mechanical FEM approach. The results reveal potential reliability issues and a specific evolution of the stress in the tungsten layer.