ASM International (Belgium)

Dry deposited and dry developed photoresist continue to demonstrate low defectivity and roughness with 0.33NA imaging. This work showcases a test vehicle that was developed on 0.33 NA to characterize the dry resist performance at P26L/S single exposure and validate defectivity performance through large area electrical yield measurement. The effect of different process parameters such as underlayer, post exposure bake, dry development and mask bias, on post litho and post etch performance are evaluated using this test vehicle (e.g., we showed that by optimizing dry development chemistry we can improve roughness without impact to dose to size). The electrical yield in large area (1m long meander and fork-fork structures) is measured post a W-damascene based metallization, and is used to verify the yield benefit of the optimized resist chemistry. This vehicle offers the ability to co-optimize process parameters to demonstrate best roughness and defectivity. at improved sensitivity enabling us to push the limits of the RLS trade-off. By adopting this holistic approach, we demonstrate our readiness for high NA EUV patterning.

Backside power delivery network (BSPDN) has gained much attention due to its potential to independently optimize signal and power routing. In this work, long slit nano through silicon vias (nTSVs) is used for high-density connections between frontside (FS)-patterned buried power rails (BPRs) and orthogonally patterned metal rails on the wafer backside (BS). These nTSVs are in situ patterned on top of BPR with self-alignment using FS lithography, and the length of the slits can also be tuned. This design relaxes overlay requirements for BS patterning that are typically stringent due to wafer grid distortions during bonding. Additionally, extreme wafer thinning stopping on a 10 nm Si0.75Ge0.25 etch stop layer (ESL) is enabled using an optimized thinning sequence with excellent total thickness variation (TTV) control. For the first time, low resistance barrier-free Molybdenum (Mo)-filled nTSVs are demonstrated, confirming the potential for further scaling compared to TiN/W-filled counterparts.

In EUV lithography, the underlayers (ULs) play a crucial role for EUV exposure dose reduction as well as the prevention of the pattern collapse of the resist. In this work, we have focused on the EUV exposure dose reduction which is important for cost reduction and productivity enhancement. To accomplish so, we have developed an dry deposited underlayer engineered for metal oxide resist (MOR). A series of ULs with various chemistry, thickness, and processing conditions were screened with MOR resist using ASML’s NXE3400 EUV exposure system to print 14nm dense line CD. We observed a 27% dose reduction on the best deposited underlayer compared to spin on glass (SOG) UL. In addition to the exposure dose reduction, we observed that unbiased roughness values (LWR 2.44nm and LER1.86 nm) is maintained the same as SOG UL (LWR: 2.49 nm and LER 1.86 nm). Furthermore, the defect free window is comparable to the SOG process. Considering all these advantages, the dry deposited ULs could be one of the underlayer candidates for high NA EUV lithography.

We report on an improved thermally-stable, high-performance CMOS RMG FinFET platform for DRAM-periphery beyond the 10nm node. This is a first demonstration of novel Mo and MoN work-function metal (WFM) integration into a high-performance dual-WFM + dual-dipole logic RMG flow, capable of enduring high thermal-budget linked to memory-array fabrication. We demonstrate superior N/P Vt balance compared to a TiN/TiAl dual-WFM + dual-dipole CMOS reference, as well as 0.12V PMOS Vt with Mo pWFM coupled with p-dipole down to scaled gate-lengths with excellent short-channel control.

Dual monopole exposure has been proposed1 as a way to improve imaging performance in EUV lithography by reducing the loss of contrast from image fading caused by the image shifts for the two poles of a dipole source. Simulations showed that the imaging advantages can be significant, with more than 15% image contrast improvements predicted. This paper presents experimental wafer data to demonstrate and verify the predicted advantages. The observed imaging enhancements include: • 18% better NILS (Normalized Image Log-Slope) for 28nm pitch patterns. • Better tip-to-tip patterns enabling gaps as much as 3nm smaller than normal patterning. Tip-to-tip LCDU and exposure latitude were improved at the same time, for better overall T2T capability. • Best focus offsets between three pitches: P28, P56 and P96 was reduced from 30nm range to nearly zero. • Smaller LWR (Line-Width Roughness), as much as 20% depending on pitch. • Reduced micro-bridging defects in the “stochastic cliffs” of narrow trenches, as large as a 40X defect density reduction for narrow trenches with 82nm pitch. Our experimental results validate the substantial imaging advantages seen by initial simulations. In addition to verifying dual monopole imaging advantages, our experiments have measured the pole-to-pole image shift δx_P2P, an important parameter relating to image contrast which has never been measured before. This important parameter depends on the detailed mask structure as well as the specific shape and location of the source poles. Our measured δx_P2P was consistent with simulated expectations.

Everyone who deals with the history of linguistics must have met with the name of E. F. K. Koerner. Last year, the sad news arrived that Koerner had died. His life was colourful and is known to those who know (see, e.g., Cowan -Foster 1989, Swiggers 1999 and most recently Joseph 2021), so here I will only mention its main stops. Koerner was born in a Grenzland: in Hofleben (Mlewiec) near Thorn (Toruń); this, perhaps, was the reason that he was aware that things are often not as clear as people not born in Grenzländer often think. After finishing high school in 1960 in Krefeld, where his family eventually settled, sharing the wanderer fate of many German families after WW II, he first served in the military, which apparently gave him what not a few intellectuals lack: the awareness that there are more important things than those they write about. It was not until 1968 that he finished his MA studies with a thesis on the German subjunctive submitted at the University of Gießen. More importantly, in 1971 he defended his dissertation on Saussure at Simon Fraser University in Canada, which was published in 1973 (Koerner 1973) . From then on, he worked continuously in the history of linguistics and became the most visible and active person in this field. In 1976, he even went "into the wilderness" and accepted the offer of an associate professorship at the University of Ottawa as the chance of lifetime, as he wrote himself, to advance the study of the history of the language sciences. Among his numerous activities, the most important was editing the journal Historiographia Linguistica and the series Amsterdam Studies in the Theory and History of Linguistic Sciences. After his retirement from the university in 2001, he returned home, to Berlin, but continued, with no less passion, his work in the historiography of linguistics. If I think about Koerner's work and the inspirations one can find in it, what first occurs to me is his appeal for specialization or professionalization in the historiography of linguistics: the demand for doing linguistic historiography not as a "byproduct", but as a separate discipline. This appeal is still relevant, or it at least seems to be, judging from the example provided by the volume of the Oxford Handbooks dedicated to the history of linguistics (Allan 2013) that is marked by a remarkable "non-professionalism": an absence of both criticism of the sources and a theoretical frame. It is symptomatic that Koerner did not participate in this volume. Another thing is, of course, to what extent such a demand for a "professional"

Extending 0.33 NA extreme ultraviolet single patterning to 28-nm pitch becomes challenging in stochastic defectivity, which demands high-contrast lithographic images. The low-n attenuated phase-shift mask (attPSM) can provide superior solutions for individual pitches by mitigating mask three-dimensional effects. The simulation and experiment results have shown substantial imaging improvements: higher depth of focus at similar normalized image log slope and smaller telecentricity error values than the best binary mask configuration. In this work, the exploration of low-n attPSM patterning opportunity for pitch 28-nm metal design is investigated. Using generic building block features, the lithographic performance of the low-n attPSM is compared with the standard binary Ta-based absorber mask. In addition, the impact of mask tone (bright field (BF) versus dark field) on the pattern fidelity and process window is evaluated both by simulations and experiments. The results indicate that BF low-n attPSM provides the best patterning performance. Consequently, the BF low-n attPSM patterning performance is assessed with an actual imec N3 pitch 28-nm random logic metal design. The wafer data indicate BF low-n attPSM enables good patterning fidelity, as well as good overall process window with high exposure latitude (∼20 % ).

In this study, we explored the key properties and functionalities of plasma enhanced atomic layer deposition (PEALD) SiNx films, synthesized using different deposition temperatures (500–550 °C) and plasma conditions (lower and higher), both on 300 mm blanket Si and on several integrated 3D topology substrates, at the thicknesses relevant for diverse nanoscale applications. Our study shows that with an increase of temperature (500–550 °C), a small reduction in HF wet etch rate (1.1–0.69 nm/min), and H content (9.6% vs 7.4%) was observed. When using higher plasmas, significant improvements in blanket properties were observed. The films were denser (2.95 g/cm3), exhibited lower H content (2.4%), showed better etch rates (0.39 and 0.44 nm/s for HF and CF4 based), and SiNx grew without any nucleation delay on alternative Si1−xGex channel surfaces. The vertical and lateral conformality was found to be similar and appears not to be impacted with the plasma conditions. Extensive steam oxidation barrier studies performed at the sidewalls of different aspect ratio lines showed the PEALD SiNx liner scaling potentiality down to 1 nm when deposited using higher plasma. In addition, the outer gate and inner spacer properties were found to be superior (with lower loses) for higher plasma films when subjected to several dry etch, strips, and H3PO4 chemistries. The outstanding conformality (90%–95% on aspect ratios ≤10:1) combined with excellent high end material properties in the ultrathin regimes (1–10 nm) corroborate the virtue of PEALD SiNx toward integration in scaled down and advanced nanoelectronics device manufacturing.