Thermally stable ZrN/Zr3N4 bilayered barrier system for through-Si-via process

We propose the use of a system composed of successively deposited ZrN (diffusion barrier)/Zr3N4 (insulating layer) barrier layers with the same constituents in the via-last through-Si-via (TSV) process. A preliminary examination of low-temperature-deposited Zr3N4 films by reactive sputtering reveals that the films show good characteristics as an insulating layer comparable to those of SiNx films prepared at low temperatures. The TSV model system of Cu/ZrN/Zr3N4/Si tolerates annealing at 500 °C for 60 min without any change in structure and/or configuration, showing good thermal stability as a candidate TSV barrier system.