Resistless EUV lithography: photon-induced oxide patterning on silicon

TL;DR

This paper demonstrates a resistless EUV lithography technique that uses photon-induced oxide patterning on silicon, achieving 75 nm half-pitch features without photoresist, potentially overcoming current resolution limits.

Contribution

It introduces a novel resistless EUV patterning method on silicon, enabling high-resolution oxide patterning without traditional photoresists.

Findings

Achieved 75 nm half-pitch SiO2/Si gratings.

Demonstrated photon-induced oxide growth on H-terminated silicon.

Showed potential for resistless EUV lithography to surpass current resolution limits.

Abstract

In this work, we show the feasibility of extreme ultraviolet (EUV) patterning on an HF-treated Si(100) surface in the absence of a photoresist. EUV lithography is the leading lithography technique in semiconductor manufacturing due to its high resolution and throughput, but future progress in resolution can be hampered because of the inherent limitations of the resists. We show that EUV photons can induce surface reactions on a partially H-terminated Si surface and assist the growth of an oxide layer, which serves as an etch mask. This mechanism is different from the H-desorption in scanning tunneling microscopy-based lithography. We achieve SiO2/Si gratings with 75 nm half-pitch and 31 nm height, demonstrating the efficacy of the method and the feasibility of patterning with EUV lithography without the use of a photoresist. Further development of the resistless EUV lithography method can be a viable approach to nm-scale lithography by overcoming the inherent resolution and roughness limitations of photoresist materials.