Cavity-based compact light source for extreme ultraviolet lithography

TL;DR

This paper introduces a novel high-power EUV light source based on a superconducting ERL-driven free-electron laser with harmonic lasing, aiming to meet the power demands of next-generation lithography.

Contribution

It proposes a compact, low-energy ERL-based FEL EUV source with harmonic lasing, reducing electron energy and facility size for high-power EUV generation.

Findings

Estimated 2 kW EUV power output.

Reduced electron beam energy to 0.33 GeV.

Compact design with a 16 mm undulator.

Abstract

A critical technology for high-volume manufacturing of nanoscale integrated circuits is a high-power extreme ultraviolet (EUV) light source. Over the past decades, laser-produced plasma (LPP) sources have been actively utilized in this field. However, current LPP light sources may provide insufficient average power to enable future manufacturing at the 3 nm node and below. In this context,accelerator-based light sources are being considered as promising tools for EUV lithography. This paper proposes a regenerative amplifier free-electron laser EUV source with harmonic lasing, drivenby a superconducting energy-recovery linac (ERL). By utilizing the nth harmonic, the required electron beam energy is reduced to 1/sqrt(n) of that in conventional schemes. The proposed configuration, employing an electron beam energy of approximately 0.33 GeV with a short-period (16 mm) undulator, is estimated to provide an average EUV power of about 2 kW. This approach significantly reduces the required electron energy and facility size relative to other accelerator-based proposals,thereby offering new possibilities for constructing high-power EUV sources with low-energy ERLs.