Novel Samsung advanced resist for thermal flow process material for nano-processing

Abstract

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, 240nm contact holes were defined by KrF lithography system, and then following a one-step thermal flow process, resulted in contact holes down to 80nm with a vertical sidewall profile. At 90nm resolution, the critical dimension variation on a 200mm wafer was less than 10nm. 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 100–150nm without any significant pattern deformation. The thermal flow process using the SMART is a promising candidate for the fabrication of nanodevices.