Impact of Defocus and Illumination on Imaging of Pitch

Impact of Defocus and Illumination on Imaging of Pitch
by Fred Chen on 10-26-2020 at 10:00 am

Impact of Defocus

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


Lithography Resolution Limits – Arrayed Features

Lithography Resolution Limits – Arrayed Features
by Fred Chen on 04-17-2020 at 6:00 am

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

A Forbidden Pitch Combination at Advanced Lithography Nodes
by Fred Chen on 03-06-2020 at 10:00 am

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


EUV is NOT Ready for 7nm!

EUV is NOT Ready for 7nm!
by Daniel Nenni on 02-27-2017 at 8:00 am

The annual SPIE Advanced Lithography Conference kicked off last night with vendor sponsored networking events and such. SPIE is the international society for optics and photonics but this year SPIE Advanced Lithography is all about the highly anticipated EUV technology. Scotten Jones and I are at SPIE so expect more detailedRead More