Recently, a patent application from TSMC [1] revealed target EUV doses used in the range of 30-45 mJ/cm2. However, it was also acknowledged in the same application that such doses were too low to prevent defects and roughness. Recent studies [2,3] have shown that by considering photon density along with blur, the associated shot… Read More
Tag: advanced lithography
Stochastic Effects from Photon Distribution Entropy in High-k1 EUV Lithography
Recent advances in EUV lithography have largely focused on “low-k1” imaging, i.e., features with pitches less than the wavelength divided by the numerical aperture (k1<0.5). With a nominal wavelength of 13.5 nm and a numerical aperture of 0.33, this means sub-40 nm pitches. It is naturally expected that larger… Read More
Stochastic Origins of EUV Feature Edge Roughness
Due to the higher energy of EUV (13.3-13.7 nm wavelength) compared to ArF (193 nm wavelength) light, images produced by EUV are more susceptible to photon shot noise.
Figure 1. (Left) 40 nm dense (half-pitch) line image projected onto wafer at 35 mJ/cm2; (Right) 20 nm dense (half-pitch) line image projected onto wafer at 70 mJ/cm2.… Read More
SPIE 2021 – ASML DUV and EUV Updates
At the SPIE Advanced Lithography Conference held in February, ASML presented the latest information on their Deep Ultraviolet (DUV) and Extreme Ultraviolet (EUV) exposure systems. I recently got to interview Mike Lercel of ASML to discuss the presentations.
DUV
Despite all the attention EUV is getting, most layers are still… Read More
SPIE Advanced Lithography
SPIE Advanced Lithography is a Digital Forum in 2021
We look forward to you joining us 22 – 26 February 2021
Attend the Advanced Lithography Digital Forum, the leading event for the lithography community and where leaders come to solve challenges in optical and EUV lithography, patterning technologies, metrology, and
How Line Cuts Became Necessarily Separate Steps in Lithography
Pretty much all the semiconductor nodes in the last two decades have had at least one layer where the minimum pitch pushes the limitation of the state-of-the-art lithography tool, with a k1 factor < 0.5, i.e., the half-pitch is less than 0.5*wavelength/numerical aperture. A number of published reports [1-4] have touched upon… Read More
Impact of Defocus and Illumination on Imaging of Pitch
In an earlier article [1], the resolution limit for the space between paired features was described by the Rayleigh criterion of ~0.6 wavelength/numerical aperture, where the numerical aperture (NA) represented the sine of the largest angle for a ray focused from the lens to a point. It is also given by the radius of the lens divided… Read More
EUV Litho, Inc.
Promoting EUV Lithography via Workshops, Consulting & Education
Introducing the EUVL Supplier Showcase: an Amazing Way to Learn Directly from Suppliers about the Newest and Best Products and Services for the EUVL Infrastructure (Blog Post)
EUV Litho, Inc., together with EUV-IUCC, is excited to announce EUVL Supplier… Read More
Lithography Resolution Limits – Arrayed Features
State-of-the-art chips will always include some portions which are memory arrays, which also happen to be the densest portions of the chip. Arrayed features are the main targets for lithography evaluation, as the feature pitch is well-defined, and is directly linked to the cost scaling (more features per wafer) from generation… Read More
A Forbidden Pitch Combination at Advanced Lithography Nodes
The current leading edge of advanced lithography nodes (e.g., “7nm” or “1Z nm”) features pitches (center-center distances between lines) in the range of 30-40 nm. Whether EUV (13.5 nm wavelength) or ArF (193 nm wavelength) lithography is used, one thing for certain is that the minimum imaged pitch … Read More