Novel resist pattern transfer process for 70 nm technology node using 157-nm lithography

A novel resist pattern transfer process for the 70 nm technology node is presented using 157-nm lithography. By using newly developed 157-nm resists and a 157-nm microstepper (NA=0.60), sub-100 nm resist patterns are fabricated. Three types of structures are presented for the pattern transfer process. Two of these are hard mask (HM) processes. and the other is a bi-layer process using Si-containing resist. For all these structures, the underlayers of resist work well as anti-reflecting layers. By optimizing the RIE gas conditions, resist patterns are successfully transferred to the underlayer. Using the HM as an etching mask, sub-100 nm gate patterns are fabricated.