A Comparative Study on Cu Drift Diffusion of Low-k Dielectrics and Thermal Oxide by use of BTS Technique

Advanced back-end processing requires the integration of low-k dielectrics and Cu. However, in the presence of an electric field and a temperature, positive Cu ions may drift rapidly through dielectric and causing reliability problems. Therefore, in this paper, Cu+ drift diffusion in two low-k materials and silicon oxide is evaluated. The drift diffusion is investigated by measuring shifts in the flat band voltage of capacitance-voltage measurements on Cu gate capacitors after bias thermal stressing. The Cu+ drift late in $SiO_{x}C_{y}\;(2.85{\pm}0.03)$ and Polyimide(2.7${\leq}k{\leq}3.0$) is Considerably lower than in thermal oxide.

BTS 방법을 사용한 Low-K 유전체 물질들과 산화막의 Cu 드리프트 확산에 대한 비교 연구