Readiness of EUV Lithography for Insertion into Manufacturing: The IMEC EUV Program

Abstract

The EUV program at imec aims at identifying the critical issues to prepare EUV lithography for insertion into high volume IC production. The program started in 2006 with the 0.25 NA ASML Alpha Demo Tool and has since then evolved around several focus areas. 1) scanner performance, reliability and monitoring, 2) definition and verification of OPC strategies for generic and EUV specific imaging effects 3) reticle defectivity, focusing on multi-layer defects, reticle handling and reticle cleaning, 4) resist screening, focusing on identification of materials that not only simultaneously give optimal performance in terms of resolution, line width roughness and sensitivity, but that also allow adequate transfer of the EUV-fabricated patterns into the underlying layers and 5) implementation of EUV lithography into fabrication of representative device structures. Since 2011 The Alpha Demo Tool has been replaced by the ASML NXE:3100, allowing higher resolution and productivity. In this paper, selected highlights in the latest achievements of the imec EUV program will be discussed.

Scanning coherent diffractive imaging methods for actinic EUV mask metrology

“…1 However, the key issue to solve, apart from the source power performance gap, still remains the reliable detection and repair of mask defects. 2,3 Actinic mask metrology, being regarded as an essential part of the EUV mask infrastructure, is a major challenge and methods beyond the state-of-the-art are needed.…”

In situ characterization of nano-scale pattern roughness during resist dissolution process

“…The fabrication of nano-scale patterns become more and more difficult as the semiconductor industry advance to more stringent pattern sizes in the sub-10 nm level [1][2][3][4]. Resist materials have played a large role in supporting these technological shifts into finer resolutions, while maintaining acceptable sensitivity and line width roughness/line edge roughness (LWR/LER).…”

A two-step method for fast and reliable EUV mask metrology

“…Extreme ultraviolet (EUV) lithography has been developed over the past decades and is considered the most promising technique for upcoming technology nodes with the industry getting ready for high-volume manufacturing. 1 One of the major challenges to be solved remains the reliable and high-throughput detection of mask defects. 2,3 Actinic mask metrology, being regarded as an essential part of the EUV mask infrastructure, is a major challenge and methods beyond the state-of-the-art are needed for patterned mask inspection.…”