Electrical Characterization of the Backside Interface on BSI Global Shutter Pixels with Tungsten-Shield Test Structures on CDTI Process

A new methodology is presented using well known electrical characterization techniques on dedicated single devices in order to investigate backside interface contribution to the measured pixel dark current in BSI CMOS image sensors technologies. Extractions of interface states and charges within the dielectric densities are achieved. The results show that, in our case, the density of state is not directly the source of dark current excursions. The quality of the passivation of the backside interface appears to be the key factor. Thanks to the presented new test structures, it has been demonstrated that the backside interface contribution to dark current can be investigated separately from other sources of dark current, such as the frontside interface, DTI (deep trench isolation), etc

Reducing the environmental impact of surgery on a global scale: systematic review and co-prioritization with healthcare workers in 132 countries

Abstract Background Healthcare cannot achieve net-zero carbon without addressing operating theatres. The aim of this study was to prioritize feasible interventions to reduce the environmental impact of operating theatres. Methods This study adopted a four-phase Delphi consensus co-prioritization methodology. In phase 1, a systematic review of published interventions and global consultation of perioperative healthcare professionals were used to longlist interventions. In phase 2, iterative thematic analysis consolidated comparable interventions into a shortlist. In phase 3, the shortlist was co-prioritized based on patient and clinician views on acceptability, feasibility, and safety. In phase 4, ranked lists of interventions were presented by their relevance to high-income countries and low–middle-income countries. Results In phase 1, 43 interventions were identified, which had low uptake in practice according to 3042 professionals globally. In phase 2, a shortlist of 15 intervention domains was generated. In phase 3, interventions were deemed acceptable for more than 90 per cent of patients except for reducing general anaesthesia (84 per cent) and re-sterilization of ‘single-use’ consumables (86 per cent). In phase 4, the top three shortlisted interventions for high-income countries were: introducing recycling; reducing use of anaesthetic gases; and appropriate clinical waste processing. In phase 4, the top three shortlisted interventions for low–middle-income countries were: introducing reusable surgical devices; reducing use of consumables; and reducing the use of general anaesthesia. Conclusion This is a step toward environmentally sustainable operating environments with actionable interventions applicable to both high– and low–middle–income countries

Développement et caractérisation de mémoires non volatiles OxRAM innovantes fortement intégrées à des transistors SOI pour les noeuds avancés

La mémoire résistive à la base des oxydes de transition métallique (ReRAM) est une classe de technologies de mémoire non volatile dans lesquelles la commutation entre états de mémoire est rendue possible par la décomposition réversible de l’oxyde au moyen de la création et de la dissolution d’un chemin de percolation (filament). Les principaux avantages de cette technologie résident dans l’évolutivité de la cellule de mémoire, principalement en raison de la dimension inférieure à 10 nm du filament, de sa faible consommation d’énergie (<300 pJ / commutateur) et de la compatibilité des matériaux avec la technologie CMOS avancée. Néanmoins, deux obstacles majeurs ont jusqu'à présent empêché la mise en œuvre de ReRAM dans les réseaux de grande taille: premièrement, la nécessité d'une tension de claquage initiale supérieure à la tension de fonctionnement et, deuxièmement, les composantes de variabilité intrinsèque et extrinsique résultant de l'interaction des matériaux à son environnement ainsi qu’à la nature stochastique fondamentale de la conduction percolative. Ce travail est axé sur la technologie ReRAM à base de HfO2. D'abord, des alliages d'HfO2 sont étudiés. Dans la seconde partie, l’alliage HfSiOx proposé est intégré dans le BEOL d’un procédé de 130 nm et l’impact de l’intégration de la zone de commutation dans la formation, la commutation, l’évolution du taux d’erreur et la conservation des données est étudié. Dans la dernière partie, une intégration basée sur HfO2 dans le MOL ancien d’un processus CMOS FDSOI 300 mm avancé est étudiée, qui étudie les performances et les limitations standard de HfO2 ReRAMTransition Metal Oxide ReRAM is a class of non-volatile memory technologies where the switching between memory states is enabled by the reversible breakdown of the oxide by means of the creation and dissolution of a percolation path (filament). The main advantages of the technology lie in the scalability of the memory cell –mainly owed to the sub 10nm dimension of the filament, its low power consumption (< 300 pJ/ switch) and material compatibility to advanced CMOS. Nevertheless, there are two major roadblocks that have prevented so far the implementation of ReRAM in large arrays: first, the requirement for an initial breakdown happening voltages significantly higher than the operating voltage range and second, the intrinsic and extrinsic variability components arising from material interaction to its environment as well as the fundamental stochastic nature of percolative conduction. This work, is focused on HfO2 based ReRAM technology. In the first part, we investigate different dopants to engineer the conductive properties of HfO2 by combining a first-principles approach and in-depth material characterization techniques. In the second part, the proposed HfSiOx alloy is integrated in the BEOL of a 130nm process and the impact of the integration of the switching zone in forming, switching, error rate evolution and data retention is investigated. In the last part, a HfO2 based integration in the early MOL of an advanced FDSOI 300mm CMOS process is demonstrated investigating standard HfO2 ReRAM performances and limitation

Effect of Hf Metal Layer on the Switching Characteristic of HfOX-based Resistive Random Access Memory

In this study, we propose the insertion of an ultrathin Hf layer at the interface between TiN (top electrode) and HfOX (electrolyte), and then studied its effect on the device electrical properties. In order to obtain the desired switching characteristics, the Hf layer thickness must be precisely engineered. The device with optimized Hf layer thickness exhibits better uniformity and lower forming voltage. This could be explained by the role of Hf layer in the creation of permanent oxygen vacancies in the oxide layer, which facilitates the switching phenomena

Resistive RAM endurance: Array-level characterization and correction techniques targeting deep learning applications

Limited endurance of resistive RAM (RRAM) is a major challenge for future computing systems. Using thoroughendurance tests that incorporatefine-grainedread operations at the array level, we quantify for the first time temporary write failures (TWFs) caused by intrinsic RRAM cycle-to-cycle and cell-to-cell variations. We also quantify permanent write failures (PWFs) caused by irreversible breakdown/dissolution of the conductive filament. We show how technology-, RRAM programing-, and system resilience-level solutions can be effectively combined to design new generations of energy-efficient computing systems that can successfully run deep learning (and other machine learning) applications despite TWFs and PWFs. We analyze corresponding system lifetimes and TWF bit error ratio

Co-design of ReRAM Passive Crossbar Arrays Integrated in 180nm CMOS Technology

This work presents the co-integration of resistive random access memory crossbars within a 180nm Read-Write CMOS chip. TaOx-based ReRAMs have been fabricated and characterized with materials and process steps compatible with the CMOS Back-End-of-the-Line. Two different strategies, consisting in insertion of an Al2O3tunnel barrier layer and the design of a dedicated CMOS read circuit, have been developed in order to increase the cell high-to-low resistance ratio of a factor of 1000 and to reduce the sneak-path current effects by one order of magnitude. The ReRAM cells have been integrated directly on a standard CMOS foundry chip, enabling low cost ReRAM-CMOS integration. The integrated memories show a set and reset voltages of -1 and 1.3V, respectively. The measured operating voltages are compatible for low-voltage applications

Stacked Nanowires FETs: Mechanical robustness evaluation for sub-7nm nodes

session 8: advanced CMOS and New Devices ConceptsInternational audienceStacked Nanowires FETs are proposed to replace FinFET and FDSOI for sub-7nm nodes. While most studies demonstrate the performances gain offered by such structures, mechanical stability of the suspended silicon channels needs to be considered. This paper provides a fully mechanical analytical description of nanowire stacks to explain the occurrence of buckling phenomena of silicon channels

SMAD4 Loss in Colorectal Cancer Patients Correlates with Recurrence, Loss of Immune Infiltrate, and Chemoresistance

SMAD4 has shown promise in identifying patients with colorectal cancer at high risk of recurrence or death. A discovery cohort and independent validation cohort were classified by SMAD4 status. SMAD4 status and immune infiltrate measurements were tested for association with recurrence-free survival (RFS). Patient-derived xenografts from SMAD4-deficient and SMAD4-retained tumors were used to examine chemoresistance. The discovery cohort consisted of 364 patients with stage I-IV colorectal cancer. Median age at diagnosis was 53 years. The cohort consisted of 61% left-sided tumors and 62% stage II/III patients. Median follow-up was 5.4 years (interquartile range, 2.3-8.2). SMAD4 loss, noted in 13% of tumors, was associated with higher tumor and nodal stage, adjuvant therapy use, fewer tumor-infiltrating lymphocytes (TIL), and lower peritumoral lymphocyte aggregate (PLA) scores (all < 0.04). SMAD4 loss was associated with worse RFS ( = 0.02). When stratified by SMAD4 and immune infiltrate status, patients with SMAD4 loss and low TIL or PLA had worse RFS ( = 0.002 and = 0.006, respectively). Among patients receiving 5-fluorouracil (5-FU)-based systemic chemotherapy, those with SMAD4 loss had a median RFS of 3.8 years compared with 13 years for patients with SMAD4 retained. In xenografted mice, the SMAD4-lost tumors displayed resistance to 5-FU. An independent cohort replicated our findings, in particular, the association of SMAD4 loss with decreased immune infiltrate, as well as worse disease-specific survival. Our data show SMAD4 loss correlates with worse clinical outcome, resistance to chemotherapy, and decreased immune infiltrate, supporting its use as a prognostic marker in patients with colorectal cancer