초록 |
The resistance of ultralow dielectrics (ULKs) to plasma is very important during BEOL process. The plasma-damage causes carbon loss and hydrophilicity which leads to higher dielectric constant. To minimize plasma damage, it is effective to increase the carbon content of ULKs. However, mechanical properties generally decrease with increased carbon contents which inevitably lead to CMP failure. Therefore, it is critically important to improve the plasma resistance by increased carbon contents with high network structures in ULK. In this study, we have developed the propylene-bridged OSGs with high network structures and carbon contents. We have controlled propylene-bridge ratio to increase carbon contents and compared their effects on the plasma resistance and other properties. Nanoporous ULKs were obtained by introducing trimethoxysilyl xylitol as a reactive porogen to OSGs. ULKs (k ~ 2.3) showed the improved PID resistance and CMP processibility (E > 6 GPa) by more carbon contents. |