In‐situ operation of oxide‐based memories in a transmission electron microscope

International audienc

Seed Enhancement: A Bridging Technology (6/28/2005) Future Fab Intl. Volume 19 By Paul-Henri Haumesser, Ph.D., CEA-Leti

email Contact author Open PDF With ultra-large-scale integration progress, efficient copper metallization of the narrow features becomes challenging. Among the elementary steps involved in the metallization sequence, the most critical will probably be the deposition of a copper seed layer necessary to initiate the bulk copper electrochemical deposition (ECD). For future generations, physical vapor deposition (PVD) techniques that are currently employed will reasonably reach a limit, as they are not able to perfectly cover the sidewalls of the features. The resulting discontinuous seed layers can cause defects such as voids in the copper lines and contact holes. To overcome this, “seed enhancement ” or “seed repair ” techniques have been proposed, which are able to bridge the local discontinuities of the copper PVD layer. In this article, this concept is illustrated through the example of an electrodeposition process called ECD seed™. The benefits of this approach are demonstrated, and the remaining challenges are discussed

Electroless deposition of CoWP: Material characterization and process optimization on 300 mm wafers

International audienceThe use of copper as a metal for interconnections has driven the apparition of new technological solutions. Selective barriers against copper diffusion deposited by electroless reaction bring interests in term of electromigration. In this article, CoWP electroless barriers deposited in a 300 mm Semitool Raider equipment are studied. Good uniformity for a standard thickness of 15 nm is demonstrated. Different growth rates of the barrier as a function of copper grain orientation are observed. The composition of the barrier is constant throughout the film. The deposition is selective, but corrosion phenomena and a superficial metallic contamination on the interline dielectric are revealed. The selectivity of the process is confirmed electrically for 12 nm thick barriers. The impact of copper corrosion on line resistance is addressed through preclean optimization

Electroless deposition of Co-based barriers: selectivity, corrosion and growth properties.

International audienceElcctroless metallic caps are convincing alternatives to standard SiC(N) barriers for the 45 nm technology node and beyond to improve electromigration resistance and limit the dielectric constant of the structures. In this work, particular emphasis is put on possible selectivity issues, corrosion of the copper lines and nucleation/growth properties for two processes (Pd-activated Co\VP and Pd-free CoWB) deprniited in an industrial 300 mm equipment Co\VP process exhibits promising results for 12 nm nominal thickness. For both processes, the control of the preclean step seems to be fundamental to limit copper corrosion. Under optimal conditions, line resistance increase is limited to less than 3 %

Investigation of Forming, SET, and Data Retention of Conductive-Bridge Random-Access Memory for Stack Optimization

International audienceIn this paper, we investigate in depth Forming, SET, and Retention of conductive-bridge random-access memory (CBRAM). A kinetic Monte Carlo model of the CBRAM has been developed considering ionic hopping and chemical reaction dynamics. Based on inputs from ab initio calculations and the physical properties of the materials, the model offers the simulation of both the Forming/SET and the Data Retention operations. It aims to create a bond between the physics at atomic level and the device behavior. From the model and experimental results obtained on decananometric devices, we propose an understanding of the physical mechanisms involved in the CBRAM operations. Using the consistent Forming/SET and Data Retention model, we obtained good agreement with the experimental data. Finally, the impact of each layer of the CBRAM on the Forming/SET behavior is decorrelated, allowing an optimization of the performance

Carbon monoxide and prognosis in smokers hospitalised with acute cardiac events: a multicentre, prospective cohort studyResearch in context

Summary: Background: Smoking cigarettes produces carbon monoxide (CO), which can reduce the oxygen-carrying capacity of the blood. We aimed to determine whether elevated expiratory CO levels would be associated with a worse prognosis in smokers presenting with acute cardiac events. Methods: From 7 to 22 April 2021, expiratory CO levels were measured in a prospective registry including all consecutive patients admitted for acute cardiac event in 39 centres throughout France. The primary outcome was 1-year all-cause death. Initial in-hospital major adverse cardiac events (MAE; death, resuscitated cardiac arrest and cardiogenic shock) were also analysed. The study was registered at ClinicalTrials.gov (NCT05063097). Findings: Among 1379 patients (63 ± 15 years, 70% men), 368 (27%) were active smokers. Expiratory CO levels were significantly raised in active smokers compared to non-smokers. A CO level >11 parts per million (ppm) found in 94 (25.5%) smokers was associated with a significant increase in death (14.9% for CO > 11 ppm vs. 2.9% for CO ≤ 11 ppm; p  11 ppm was associated with a significant increase in MAE in smokers during initial hospitalisation after adjustment for comorbidities (odds ratio [OR] 15.75, 95% CI [5.56–44.60]) or parameters of in-hospital severity (OR 10.67, 95% CI [4.06–28.04]). In the overall population, CO > 11 ppm but not smoking was associated with an increased rate of all-cause death (HR 4.03, 95% CI [2.33–6.98] and 1.66 [0.96–2.85] respectively). Interpretation: Elevated CO level is independently associated with a 6-fold increase in 1-year death and 10-fold in-hospital MAE in smokers hospitalized for acute cardiac events. Funding: Grant from Fondation Coeur & Recherche

Temporal Trends in Transcatheter Aortic Valve Replacement in France: FRANCE 2 to FRANCE TAVI

International audienceBackground - Transcatheter aortic valve replacement (TAVR) is standard therapy for patients with severe aortic stenosis who are at high surgical risk. However, national data regarding procedural characteristics and clinical outcomes over time are limited. Objectives - The aim of this study was to assess nationwide performance trends and clinical outcomes of TAVR during a 6-year period. Methods - TAVRs performed in 48 centers across France between January 2013 and December 2015 were prospectively included in the FRANCE TAVI (French Transcatheter Aortic Valve Implantation) registry. Findings were further compared with those reported from the FRANCE 2 (French Aortic National CoreValve and Edwards 2) registry, which captured all TAVRs performed from January 2010 to January 2012 across 34 centers. Results - A total of 12,804 patients from FRANCE TAVI and 4,165 patients from FRANCE 2 were included in this analysis. The median age of patients was 84.6 years, and 49.7% were men. FRANCE TAVI participants were older but at lower surgical risk (median logistic European System for Cardiac Operative Risk Evaluation [EuroSCORE]: 15.0% vs. 18.4%; p < 0.001). More than 80% of patients in FRANCE TAVI underwent transfemoral TAVR. Transesophageal echocardiography guidance decreased from 60.7% to 32.3% of cases, whereas more recent procedures were increasingly performed in hybrid operating rooms (15.8% vs. 35.7%). Rates of Valve Academic Research Consortium-defined device success increased from 95.3% in FRANCE 2 to 96.8% in FRANCE TAVI (p < 0.001). In-hospital and 30-day mortality rates were 4.4% and 5.4%, respectively, in FRANCE TAVI compared with 8.2% and 10.1%, respectively, in FRANCE 2 (p < 0.001 for both). Stroke and potentially life-threatening complications, such as annulus rupture or aortic dissection, remained stable over time, whereas rates of cardiac tamponade and pacemaker implantation significantly increased. Conclusions - The FRANCE TAVI registry provided reassuring data regarding trends in TAVR performance in an all-comers population on a national scale. Nonetheless, given that TAVR indications are likely to expand to patients at lower surgical risk, concerns remain regarding potentially life-threatening complications and pacemaker implantation. (Registry of Aortic Valve Bioprostheses Established by Catheter [FRANCE TAVI]; NCT01777828)