Pattern density multiplication by direct self assembly of block copolymers: Towards 300mm CMOS requirements
Résumé
In this paper we investigate the possibility to reach 300mm CMOS requirements by integrating graphoepitaxy of PS-b-PMMA self-assembly. Different schemes to integrate DSA process by using 193nm dry lithography or e-Beam lithography will be presented. Moreover, several challenges like solvent compatibility, bake kinetics and defectivity will be addressed. Concerning defectivity, we will propose a methodology in order to evaluate and optimize the long range order induced by graphoepitaxy of the block copolymer DSA. This approach affords the monitoring of the overall block copolymer self-assembly process and enables us to easily optimize the parameters required for a long-range order structuration, leading to a near zero-defects block copolymers self-assembled arrays. Transfer capabilities of the PS masks in the bulk silicon substrate by using plasma-etching will be also detailed, both with the film on bare silicon or organized with graphoepitaxy approaches. These results show the high potential of DSA to be integrated directly into the conventional CMOS lithography process in order to achieve high resolution and pattern density multiplication, at a low cost.