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
Blur, not Wavelength, Determines Resolution at Advanced Nodes
Lithography has been the driving force for shrinking feature sizes for decades, and the most easily identified factor behind this trend is the reduction of wavelength. G-line (436 nm wavelength) was used for 0.5 um in the late 1980s [1], and I-line (365 nm wavelength) was used down to 0.3 um in the 1990s [2]. Then began the era of deep-ultraviolet… Read More
Cautions In Using High-NA EUV
High-NA EUV has received a lot of attention ever since Intel put the spotlight on its receiving the first 0.55 NA EUV tool from ASML [1], expected in 2025. EUV itself has numerous issues which have been enumerated by myself and others, most notoriously the stochastic defects issue. There are also a host of issues related to the propagation… Read More
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
ASML- A Semiconductor Market Leader-Strong Demand Across all Products/Markets
– Strong demand across logic/memory & leading/trailing edge
– Customers want units fast-no time to test
– The main question is can ASML ramp to meet demand?
Revenue & Earnings low due to systems being rushed to customers
ASML reported Euro 4B in sales and Euro 1B in net income which while within guidance… 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
Contrast Reduction vs. Photon Noise in EUV Lithography
The stochastic behavior of images formed in EUV lithography has already been highlighted by a number of authors [1-3]. How serious it appears depends on the pixel size with which the photons are bunched. Generally, though, for features of around 20 nm or less, even 1 nm can have at least a +/- 15% gradient across it, which is still a
KLAC- Great QTR & Guide- Foundry/logic focus driver- Confirms $75B capex in 2021
– KLA put up an excellent quarter and Guide
– Rising above the increasing tide of orders
– Confirms $75B capex in 2021 with upside
– Foundry & Logic continue to be the sweet spot for KLA
Business is very very good and getting better
-Revenues came in at $1.8B with EPS of $3.85, all above the range
-Guidance… Read More
SALELE Double Patterning for 7nm and 5nm Nodes
In this article, we will explore the use of self-aligned litho-etch-litho-etch (SALELE) double patterning for BEOL metal layers in the 7nm node (40 nm minimum metal pitch [1]) with DUV, and 5nm node (28 nm minimum metal pitch [2]) with EUV. First, we mention the evidence that this technique is being used; Xilinx [3] disclosed the… 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
More Headwinds – CHIPS Act Chop? – Chip Equip Re-Shore? Orders Canceled & Fab Delay