Next-Generation Light Source: Driving plasmas to power tomorrow’s nanolithography

Introduction

Advanced semiconductor devices are produced using extreme ultraviolet (EUV) light at just 13.5nm wavelength. This small wavelength enables patterning the smallest and smartest features on chips. The recent revolutionary introduction of EUV lithography (EUVL) was the culmination of several decades of collaborative work between industry and science – a Project Apollo of the digital age.

EUV Light Production

EUVL is powered by light that is produced in the interaction of high-energy CO2-gas laser pulses with molten tin microdroplets. The use of such lasers, however, leads to unsustainably low overall efficiency in converting electrical power to useful EUV light: delivering a watt of EUV power at the silicon wafer level currently has a megawatt footprint.

Need for Improvement

Replacing gas lasers with much more efficient solid-state lasers will significantly reduce this footprint. It is currently, however, unclear what laser wavelength and what plasma ‘recipe’ should be used. This is because we lack understanding of the underlying complex physics.

Project Objectives

MOORELIGHT will deliver the missing insight that is required to efficiently and reliably power next-generation solid-state-laser-driven EUV light sources. The project will focus on the following objectives:

1. Understanding Phase Changes: We will obtain understanding of phase changes and fragmentation of laser-impacted liquid thin tin targets and develop capabilities for laser-tailoring targets.
2. Investigating Laser Coupling: We will use tailored targets to investigate how these couple to laser light of variable wavelength and spatiotemporal profile to produce hot-and-dense plasma.
3. Advancing Predictive Plasma Modeling: This will provide insight through experiments and modeling into the optimum plasma recipe for producing EUV light, in tandem with efforts to advance predictive plasma modeling by finding the elusive atomic origins of the EUV light.

Impact

Individually, these objectives will significantly impact their related fields of science and technology. Combined, they will enable the sustainable powering of tomorrow’s EUVL and help realize the EU’s ambitions regarding its technological leadership in nanotechnology.