In-sun Park

Reduction of plasma-induced damage during intermetal dielectric deposition in high-density plasma

We have attempted to reduce the plasma-induced damage to the thin gate oxides during intermetal dielectric (IMD) gap-fill process by high-density plasma (HDP) chemical vapor deposition (CVD). It was revealed that the optimization of preheating step could reduce the damage. The H/sub 2/-based HDP CVD process was also effective in reducing plasma-induced damage compared with the conventional He-based process. The gate oxide failure was reduced remarkably at the low deposition temperatures less than 400/spl deg/C. Both the significant damage reduction and the excellent gap-fill performance were achieved by the adoption of the phosphorus silicate glass (PSG) using the low temperature H/sub 2/-based HDP CVD technique.

Plasma-induced damage on sub-5 nm gate oxide by PECVD-Ti process

Plasma-induced damage by the PECVD-Ti process on the leakage current of sub-5 nm gate oxide was investigated. The plasma conditions during the deposition of PECVD-Ti critically affected characteristics of the gate oxide such as the leakage current and the breakdown voltage. Lowering of plasma power in a deposition step improves the gate oxide properties but cannot clearly reduce all gate oxide failure. According to plasma damage monitoring analysis, a large plasma damage during the plasma ignition step was observed, which indicates that failure of the gate oxide was due to the unbalanced plasma ignition in the deposition step. It is very important to optimize process parameters and to control system conditions to prevent the unbalanced plasma ignition during the PECVD-Ti process.