DSA patterns line pitches down to 18nm
Imec has demonstrated the capability of directed self-assembly (DSA) to pattern line/spaces with a pitch as small as 18nm, using a high-chi block copolymer (high-χ BCP) based process under high volume manufacturing (HVM) conditions.
An optimized dry-etch chemistry was used to successfully transfer the pattern into an underlying thick SiN layer – which will enable further defectivity inspection. These results confirm the potential of DSA to complement traditional top-down patterning for the industrial fabrication of sub-2nm technology nodes.
The further miniaturization of devices will require the patterning of features that have critical pitches below 20nm. For these small feature sizes, the traditional top-down lithography patterning is increasingly challenged with issues that are inherent to the reaction of the photosensitive materials with light – such as stochastic printing failures and line-edge/line-width roughness (LER/LWR).