A resist flow process using a cross-linkable additive called the Samsung advanced resist for thermal flow process (SMART) was studied. SMART consists of conventional polyhydroxystyrene-based polymers and additives inducing thermal cross-linking reactions with the base polymers. With the SMART resist, 240 nm contact holes were defined by KrF lithography system, and then following a one-step thermal flow process, resulted in contact holes down to 80 nm with a vertical sidewall profile. At 90 nm resolution, the critical dimension variation on a 200 mm wafer was less than 10 nm. It also showed good etch selectivity to silicon oxide due to the cross-linking reaction of the additive. The main advantage of the SMART system is a one-step process having a linear dependency of flow rate on baking temperature. The amount of resist flow can be controlled within the range of 100-150 nm without any significant pattern deformation. The thermal flow process using the SMART is a promising candidate for the fabrication of nanodevices. (c) 2007 American Vacuum Society.