Beyond 100 nm Resolution in 3D Laser Lithography: Post Processing Solutions

TL;DR

This paper presents post-processing techniques combining plasma etching and pyrolysis to surpass 100 nm resolution in 3D laser lithography, enabling nanoscale structures with controlled dimensions.

Contribution

It introduces a novel post-processing method to improve resolution and control in 3D laser lithography beyond 100 nm.

Findings

Achieved smaller feature sizes through plasma etching and pyrolysis.

Controlled overall size and cross-sectional dimensions of 3D structures.

Resolution limited by polymer properties and structure geometry.

Abstract

Laser polymerization has emerged as a direct writing technique allowing the fabrication of complex 3D structures with microscale resolution. The technique provides rapid prototyping capabilities for a broad range of applications, but to meet the growing interest in 3D nanoscale structures the resolution limits need to be pushed beyond the 100 nm benchmark, which is challenging in practical implementations. As a possible path towards this goal, a post processing of laser polymerized structures is presented. Precise control of the cross-sectional dimensions of structural elements as well as tuning of an overall size of the entire 3D structure was achieved by combining isotropic plasma etching and pyrolysis. The smallest obtainable feature sizes are mostly limited by the mechanical properties of the polymerized resist and the geometry of 3D structure. Thus the demonstrated post processing steps open new avenues to explore free form 3D structures at the nanoscale.