Optimization of Area Selective Barrier on Different Metal Interconnects

Area selective atomic layer deposition of barriers with self-assembled monolayer (SAM) is increasingly being used in device fabrication to lower resistivity between inter layer metal interconnects by eliminating the barrier between them. In this paper, selectivity of atomic layer deposition (ALD) TaN on a Cu metal surface is optimized by tuning deposition conditions of both the SAM blocking layer and ALD TaN. Furthermore, we investigate SAM selectivity performance on different metal surfaces: Co, and Ru. The selectivity efficacy of SAM is shown to be highly dependent on deposition conditions.