New functional surface treatment process and primers for high-NA EUV lithography

Abstract

For EUV high NA lithography, current conventional tri-layer procss has the critical issue both for EUV litho performance & pattern etch transfer. Especially since the latest EUV PR including CAR and MOR is very low film thickness around 10nm, Si containing hard mask (Si-HM) should be around 5nm. In this case, it is too difficult to transfer to SOC and the bottom hard mask layer. In order to prevent this critical issue, we proose new functional surface treatment process and primers (FSTP) on the conventional CVD hard mask or Si-HM. This FSTP is spin coating materials. However it is almost sigle molecular type ultra thin primer (~1nm) for all of the CVD & spin on hard mask (SiON, SiN, TiN, SiO2, SiHM, SOG and so on) not to bother fine pitch pattern transfer. Moreover, this FSTP has high universalithy to EUV PR CAR and MOR to achieve high patterning performance in EUVL. Therefore FSTP has big advantage in EUV litho process and pattern etch transfer for next generation High NA EUV process.