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Project

Extreme ultraviolet interference lithography

Lithography lies at the heart of semiconductor manufacturing for information and communications technology (ICT) devices. Until recently, mass production of ICT devices was conducted using deep ultraviolet exposure; however, the push for smaller and faster components and devices has led the ICT industry to pursue extreme ultraviolet (EUV) lithography as a viable means of production. By moving to EUV exposure, the diffraction limit of the light is reduced thereby decreasing the achievable print features. However, the printing of smaller features is more prone to stochastic print defects that can lead to device failure. Studying the formation of stochastic defects and optimization of EUV lithographic processes has proved difficult, as EUV sources with sufficient photon flux have, until recently, only been available from building-sized machines (e.g., EUV scanners) or large scale facilities such as synchrotrons or free electron lasers. An alternative source of EUV light for lithography is high-order harmonic generation (HHG), in which visible or near infrared laser pulses supplied by a tabletop laser are converted to UV or EUV light. These tabletop sources can be deployed for interference lithography of photoresist materials, thus enabling a versatile testbench for lithography. This PhD project aims to peer into the lithography process during and after EUV exposure. The project will be utilizing the HHG-based EUV sources within the newly installed imec AttoLab for lithography. The project will involve deployment of already established techniques for interference lithography joined with development of new techniques and improvements of the methodology. The diagnostics of the generated patterns will be conducted at imec’s state-of-the-art lithography analytics facilities and will be compared and reconciled with results obtained from our commercial EUV scanners. The experimental results will be used to build lithography exposure models to further our understanding of the entwined lithography physics and complex photoresist chemistry.The acquired knowledge will pave the way for mitigation of stochastic print defects while increasing throughput by reducing the effective exposure dose of EUV scanners while maintaining image fidelity.

Date:17 Aug 2021 →  Today
Keywords:Lithography, Extreme Ultraviolet, Photoresist, Patterning
Disciplines:Nanofabrication, growth and self assembly, Nonlinear optics and spectroscopy, Analytical spectrometry
Project type:PhD project