Performance of tri-layer process required for 22 nm and beyond

Silicon-containing antireflection coating (SiARC) and spin-on carbon (SOC) under-layers have been widely implemented for advanced semiconductor manufacturing since the 45 nm node. The combination of SiARC and SOC promises a superior solution for reflection control and a high etch selectivity. With the industry marching towards 22 nm and beyond, the tri-layer materials and processes are being finely tuned to meet the requirements. We report comprehensive evaluation results of the SiARC (with high silicon content) and carbon under-layer from manufacturing perspective. It focuses on the performances that are required to extend the tri-layer applications from the original 45 nm nodes to 22 nm and beyond, such as thickness selection, etch selectivity, resist compatibility, rework capability, and under-layer pattern wiggling issues.