Thermal Stability and Performance of NbSiTaTiZr High-Entropy Alloy Barrier for Copper Metallization

Development of better diffusion barriers for Cu metallization is one of the key issues for the microelectronics industry. Although metallic diffusion barriers offer many advantages, their application is hindered due to their inferior thermal stability relative to ceramic barriers. Here we report on a metallic diffusion barrier, NbSiTaTiZr, which shows thermal stability comparable to ceramic barriers. The outstanding performance of NbSiTaTiZr is due to its better structural and chemical stability at high temperatures.