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Background: Severe acute respiratory coronavirus virus 2 (SARS-CoV-2), able to cause pneumonia in humans, was discovered in Wuhan, Hubei Province, China. Investigations related to transmissibility are ongoing, but human-to-human transmission involving healthcare workers providing patient care and close contacts of infected patients have been confirmed. Infection control procedures are necessary to prevent transmission during delivery of health care in healthcare settings. Public health in Canada is a shared responsibility among municipal, provincial, territorial, and federal governments. Significant public health events require coordination between all levels of government and a consistent approach across jurisdictions. The objective of this summary is to describe the Public Health Agency (PHAC)’s Infection Prevention and Control (IPC) guideline on SARS-CoV-2. Methods: The PHAC’s interim guideline for infection prevention and control of 2019-nCoV in acute healthcare settings was informed by the currently limited evidence available, and adapted to the context of healthcare delivery in Canada. The guideline is based upon Canadian guidance developed for previous coronavirus outbreaks (eg, SARS and MERS), as well as the World Health Organization (WHO)’s interim guidance. Technical advice was provided by the National Advisory Committee on Infection Prevention and Control (NAC-IPC) of the Government of Canada. Interjurisdictional collaboration and decision making between multiple authorities and levels of government was facilitated using PHACs federal/provincial/territorial (FPT) Public Health Response Plan for Biological events (Fig. 1). Results: In the absence of effective drugs or vaccines, IPC strategies to prevent or limit SARS-CoV-2 transmission in healthcare settings include the following: prompt identification of signs, symptoms and exposure criteria, implementation of appropriate IPC measures (eg, contact and droplet precautions, patient isolation, N95 respirator plus eye protection when performing aerosol-generating medical procedures on a person under investigation), and etiologic diagnosis. Guideline recommendations are informed by collective expert interpretation of available evidence. Recommendations cover all relevant areas including screening and assessment, public health surveillance and notification, laboratory testing and reporting, respiratory hygiene, hand hygiene, patient placement and flow, management of visitors, use of personal protective equipment, environmental cleaning and discontinuation of precautions. Conclusions: This guideline is an ever-changing document. Changes in recommendations provided may be warranted with new evidence, changes in WHO guidelines, or other identified concerns. FPT governments continue to work collaboratively to ensure that Canada is ready to respond to public health events and is prepared to protect the health of Canadians. Opportunities for international collaboration on IPC products, as well as knowledge exchange and mobilization, continue to thrive.
Background: Surgical site infections (SSI) related to colorectal procedures are detrimental to patients and publicly reportable events. Our institution implemented a successful bundle of interventions to decrease SSI rates in 2014. In 2018, compliance started to wane, with a concurrent increase in infections. In an effort to enhance compliance and incorporate up-to-date information, we convened a multidisciplinary team to streamline this process. Methods: Our team evaluated published studies on successful bundle components and updates to professional guidelines for SSI prevention to determine adjustments. Modifications included allowing surgeon preference for (rather than mandating) wound protector use and simplification of clean closure protocol (determined by intraoperative contamination, leading to more efficient closure time). In addition, measures were added to achieve perioperative patient optimization (maintenance of normothermia, prevention of intraoperative hypoxia, tighter glucose control and postoperative bathing). The bundle was implemented in stages starting January 2019. SSI rates were monitored throughout the process using NHSN definitions, and rates were compared using χ2 analysis (Epi Info, CDC). Results: From 2015 to 2017, bundle compliance was 90%, and 8 SSIs (rate, 3.8 per 100 procedures) were detected (Table 1). In 2018, compliance was 82%, with 4 SSIs (rate, 6.6 per 100 procedures). From January through September 2019, SSI rates decreased to a rate of 4.8 per 100 procedures, with notable increase in superficial SSI, with zero cases of deep or organ-space infections. Feedback from operating-room personnel indicated their commitment to bundle compliance and perceived intraoperative time savings. Conclusions: Revamping an existing colorectal SSI bundle, including relaxation of time-intensive and expensive intraoperative measures and increased focus on evidence-based guidelines, resulted in decreased deep-organ space SSI rates, as well as increased satisfaction from procedural team members. Successful implementation of care pathways to prevent infections is an iterative process and requires the engagement of practitioners.
To reduce time-to-knowledge and costs associated with wafer scale processing a laboratory scale copper electrochemical deposition (ECD) system was developed for screening new organic additives which promote bottom-up fill in interconnect trenches and vias. This new setup enables working process conditions and functionality trends to be identified for open source and proprietary suppressors and levelers at leading edge feature sizes (sub 50nm). The laboratory results can then be compared to the in-line wafer scale plating tool results to ensure their compatibility. A reliable laboratory setup that can mimic the dynamic conditions found inside the wafer scale plating tool will enable the main objective of this work to be efficiently realized. The main objective is to test two previously published models describing copper fill inside the trenches by bridging the gap between fundamental electrochemical measurements and wafer scale plating results. To date this work will focus on the reliability and transferability of plating results between the laboratory setup and a wafer scale plating tool and present preliminary data using gap fill and bottom-up growth ratio as performance metrics.
A thermal metalorganic atomic layer deposition (ALD) process was developed for the in situ, sequential growth of Pt/TaNx stacks for use as barrier/seed stacks for subsequent copper electroplating. Ultrathin platinum films were deposited by alternating pulses of (methylcyclopentadienyl)trimethylplatinum (MeCpPtMe3) and oxygen (O2) as co-reactants. An ALD process window was established and optimized by investigating saturation of Pt film-growth rate versus MeCpPtMe3 and O2 exposure as controlled by the length of reactant pulses and the duration of the inert gas purge cycles separating the reactant pulses. The resulting low-temperature (300 °C) ALD Pt process yielded uniform and continuous Pt films with typical carbon and oxygen impurity levels around, respectively, 2.5 and 1 at.%. Film conformality was nearly 100% in 120-nm trench structures with 11:1 aspect ratio.
Ultra-thin platinum (Pt) films grown by atomic layer deposition (ALD) have been investigated as an alternative to conventional physical vapor deposited (PVD) Cu as seed layer for copper (Cu) electroplating. The wetting angles between the electrolyte and both Pt and Cu seed layers were analyzed using sessile-drop contact-angle analysis prior to plating. Both constant current and pulse reverse current (PRC) were applied to electroplate Cu on both types of blanket seed layers. Scanning electron microscope (SEM) revealed that Cu nucleation density on ALD Pt is lower than on its PVD Cu counterpart, after 30 seconds plating using PRC. Nevertheless, Cu nuclei were observed after only 1.0 minute plating on ALD Pt surfaces, and continuous Cu films were achieved at longer plating times. To fill trench structures coated with ALD Pt/TaN, PRC was applied using the same organic-additive-free electrolyte. Initial results suggest that these seed layers were adequate for ECD fill of trenches with 200 nm feature size and aspect ratio 7:1. The composition and microstructure of the Cu films were analyzed by Auger electron spectroscopy (AES), X-ray diffraction (XRD), and cross-sectional transmission electron microscopy (TEM). Thermal stability of the Cu/Pt system was examined by annealing in forming gas at 450°C for 1 hour and subsequent analysis by XRD and TEM.
Solid-state wetting experiments were carried out to derive the work of adhesion (adhesion energy) of pertinent Cu/liner interfaces via the Young–Dupré equation using contact-angle measurements of the Cu equilibrium crystal shape on Ta and TaNx liners. Four types of liner surfaces were examined: untreated sputtered Ta (uSp-Ta), untreated sputtered TaNx (uSp-TaN), untreated atomic layer deposited (ALD) TaNx (uALD-TaN), and indium surfactant-treated ALD TaNx (tALD-TaN). All Cu-liner stacks were subsequently annealed at 600 °C for 48 h in a forming gas (95% Ar/5% H2) ambient. For Cu/uSp-Ta, the work of adhesion was found to be 2170 mJ/m2, corresponding to an average contact angle of 74°, while for Cu/uSp-TaN, the work of adhesion amounted to 1850 mJ/m2 for an average contact angle of 85°. Alternatively, the work of adhesion for Cu/uALD-TaN was determined to be 1850 mJ/m2, corresponding to an average contact angle of 85°, while for Cu/tALD-TaN, the work of adhesion was 2280 mJ/m2, at an average contact angle of 70°. These findings indicate that the highest degree of surface wetting occurs for the indium surfactant-treated ALD TaNx. It is thus suggested that surfactant treatment causes a reduction in the energy barrier to Cu nucleation, resulting in an enhancement in Cu wetting characteristics and a more uniform concentration of Cu nucleation sites. A critical potential outcome is the formation of atomically smooth Cu-liner interfaces with enhanced adhesion characteristics.
Nanocomposite thin films consisting of Au nanoparticles embedded in yttria-stabilized zirconia (YSZ) were synthesized at room temperature by radio frequency magnetron co-sputtering from YSZ and Au targets and subsequently annealed in an argon atmosphere. Au microstructure and particle size were characterized as a function of annealing temperature from 600 to 1000 °C by x-ray diffraction, transmission electron microscopy, scanning electron microscopy, and Rutherford backscattering spectroscopy. Spectroscopic ellipsometry was also used to determine the optical constants of the resulting films. In particular, the refractive index of the nanocomposites was found to undergo an anomalous dispersion in the spectral region where the extinction coefficient achieves its maximum. Additionally, the incorporation of Au in the YSZ matrix was found to increase the refractive index in comparison to that of YSZ. At annealing temperatures higher than 800 °C, a good agreement was found between experimental findings and theoretical models using bulk dielectric functions for Au, as modified to account for a reduced mean free path for scattering than that for free electrons. However, for annealing temperatures below 800 °C, an additional offset was required for the optical constants of Au to obtain good agreement between theory and experiment. This behavior was attributed to a relatively high atomic Au concentration in the YSZ matrix.
Responses to disasters involve many factors beyond personnel, such as medical andnon-medical equipment and supplies. When disaster teams respond, they must do so with sufficient amounts of medicine and supplies to manage all of the patients expected for several days before re-supply. In order for this process to be efficient and expedient, accurate and advanced planning for supplies needed by disaster workers is necessary. These supplies must provide for general medical care and for hazard-specific problems.
To develop a model that provides the framework for determining supply requirements for the National Disaster Medical System, Disaster Medical Assistance Teams, or other responding disaster teams in a civilian environment.
A community hospital was modeled to determine patient characteristics when presenting to an emergency department (ED), including patient demographics and chief complaint, medications administered during the emergency department visit and prescribed at discharge, and laboratory tests ordered to assess disaster team supply requirements. Data were downloaded from a patient tracking software package and abstracted from various hospital data information systems. Data from the community hospital were compared with data published from two hurricane disasters by members of the National Disaster Medical System.
To the extent possible, the model predicted the proportion of patient complaints and, therefore, the medicine and supplies needed for the management of these patients.
This model offers a first step in preparing disaster medical teams for deployment.
Observation of GaN-based islands surrounded by V-defects in the barrier layer of green LED is reported for InGaN MQWs deposited under no hydrogen or at growth temperatures of less than 800°C. Nanoscale mechanical properties of the areas enclosed and outside of the ring defects does not show any appreciable variation as measured by UFM. Chemical etching of the MQW structure in addition to cross-sectional TEM analysis ruled out the possibility of growth of inversion domains of N-polar GaN in a Ga-polar GaN matrix.
Results are presented from a systematic investigation to design and optimize a low-pressure chemical vapor deposition (CVD) process for manganese-doped zinc sulfide (ZnS:Mn) thin films for electroluminescent (EL) device applications. The CVD process used diethylzinc (DEZ), di-π-cyclopentadienyl manganese (CPMn), and hydrogen sulfide (H2S) as co-reactants and hydrogen (H2) as carrier gas. A design of experiments approach was used to derive functionality curves for the dependence of ZnS:Mn film properties on substrate temperature and flow rates (partial pressures) of DEZ, CPMn, H2S, and H2. Film physical, chemical, structural, and optical properties were examined using Rutherford backscattering spectrometry, dynamic secondary ion mass spectroscopy, x-ray photoelectron spectroscopy, nuclear-reaction analysis, x-ray diffraction, transmission electron microscopy, atomic force microscopy, and scanning electron microscopy. EL measurements were carried out on ZnS:Mn-based dielectric–sulfur–dielectric stacks incorporated into alternating-current thin-film electroluminescent devices. An optimized process window was established for the formation of films with predominantly (0 0 2) orientation, grain size larger than 0.2 μm, and Mn dopant level approximately 0.5 at.%. A brightness of 407 cd/m2 (119 fL) and efficiency of 1.6 lm/W were obtained, as measured at 40 V above threshold voltage and 60 Hz frequency.
A metal–organic thermal atomic layer deposition (ALD) approach was developed for the growth of ultrathin tantalum nitride (TaNx) films by alternate pulses of tert-butylimido trisdiethylamido tantalum (TBTDET) and ammonia (NH3). An optimized ALD process window was established by investigating saturation of film-growth rate versus TBTDET and NH3 exposures, as controlled by the length of reactant pulses and the duration of the inert gas purge cycles separating the reactant pulses. The resulting low-temperature (250 °C) ALD process yielded uniform, continuous, and conformal TaNx films with a Ta:N ratio of 1:1. Carbon and oxygen impurity levels were in the 5–8 at.% range. Associated film conformality in 100-nm trench structures with 11:1 aspect ratio was nearly 100%.
A previously developed metal-organic atomic layer deposition (ALD) tantalum
nitride (TaNx) process was employed to investigate the growth of
TaNx liners on low dielectric constant (low-k) materials for
liner applications in advanced Cu/low-k interconnect metallization schemes.
ALD of TaNx was performed at a substrate temperature of 250°C by
alternately exposing low-k materials to
tertbutylimido-tris(diethylamido)tantalum (TBTDET) and ammonia
(NH3), separated by argon purge steps. The dependence of
TaNx film thickness on the number of ALD cycles performed on
both organosilicate and organic polymer-based low-k materials was determined
and compared to baseline growth characteristics of ALD TaNx on
SiO2. In order to assess the effect of the deposition of
TaNx on surface roughness, atomic force microscopy (AFM)
measurements were carried out prior to and after the deposition of
TaNx on the low-k materials. The stability of the interface
between TaNx and the low-k materials after thermal annealing at
350°C for 30 minutes was studied by examining interfacial roughness profiles
using cross-sectional imaging in a high-resolution transmission electron
microscope (HR-TEM). The wetting and adhesion properties of Cu/low-k were
quantified using a solid-state wetting experimental methodology after
integration of ALD TaNx liners with Cu and low-k dielectrics.
The influence of surfactant-based liner post-treatment on the wetting and nucleation characteristics of ultra-thin copper (Cu) films has been examined, employing ultra-thin atomic layer deposited (ALD) tantalum nitride (TaNx) as liner material. This surfactant-based posttreatment consists of in-situ exposure of the liner to a metal-organic source containing a low surface free energy metal (Sn) surfactant, which is a potential candidate for enhancing the wetting of Cu on liner surfaces and subsequently suppressing island-type growth of Cu, due to both the high atomic volume and low surface free energy of the surfactant relative to Cu. A methodology involving thermally-enhanced de-wetting of Cu, promoted by annealing Cu/liner stacks in a forming gas (95% Ar, 5% H2) ambient under several applied thermal budgets (annealing at 350°C for 30 minutes, and at 600°C for 4, 12, and 48 hrs, respectively), was utilized to both elucidate and quantify the wetting properties of Cu on liners, via detailed analyses of the surface morphology of annealed stacks by atomic force microscopy (AFM) and scanning electron microscopy (SEM). By comparing stacks containing ALD TaNx liners to those that contain post-treated ALD TaNx liners, this method allowed an evaluation of the effectiveness of surfactant-based liner surface post-treatments in inhibiting Cu de-wetting.
Thin film electroluminescent devices employing zinc sulfide doped with manganese are extensively used for applications in which the weight, brightness and mechanical robustness requirements preclude the use of other types of displays such as cathode ray tubes or liquid crystal displays. The physical, optical and electrical properties of phosphors such as ZnS:Mn can often depend strongly on microstructure, which in turn depends on the growth and processing of the film. For this study, ZnS:Mn layers were fabricated by metalorganic chemical vapor deposition (MOCVD) in the 250°-500°C range on an Al2TiO/ In2SnO5 /glass stack. Selected samples were then subjected to a post-deposition anneal in H2S/Ar at 700°C for up to 4 hours. The microstructure of the ZnS:Mn films was examined by Transmission Electron Microscopy (TEM). For all growth and annealing conditions, the films consisted of columnar grains whose column axis was parallel to the growth direction, and which widened laterally through the thickness of the films. For the as-deposited films, the crystal structure was found to be predominantly 2H structure, with the 8H polytype being identified in the low-temperature ZnS:Mn films. The 700°C post-deposition annealing was found to initiate a solid state transformation to the cubic (3C) ZnS crystal structure. All films contained high densities of stacking faults and microtwins, whose role in the 2H-3C transformation is discussed. Also discussed are initial Ultrasonic Force Microscopy (UFM) results which suggest a correlation between the defect microstructure and the elastic response of the material.
Zinc sulfide doped with manganese is extensively used for thin film electroluminescent device applications. In order to assess the key material and process challenges, ZnS:Mn layers were fabricated by metalorganic chemical vapor deposition in the 250°-500°C range on an AlTiO/InSnO/glass stack. The microstructure of the ZnS:Mn films was examined by Transmission Electron Microscopy (TEM) as part of a larger study which fully characterizes these films by a variety of structural and chemical characterization techniques, including Rutherford Backscattering, Secondary Ion Mass Spectroscopy, Atomic Force Microscopy, Scanning Electron Microscopy and X-ray Diffraction. For all the growth conditions, the films were found to be polycrystalline having predominantly 2H hexagonal ZnS structure. The ZnS grains are found to grow columnar as the film thickness increases, also widening in the direction parallel to the substrate surface and reaching the 100 - 200 nm average lateral size at the 650 nm film thickness. The presence of the 8H ZnS polytype was detected in the low-temperature ZnS:Mn films by TEM selected area electron diffraction and confirmed by X-ray diffraction analysis. Dark field TEM imaging correlated this 8H ring with very small (∼2.5 nm) grains present throughout the low temperature film with a slightly higher density at the film/substrate interface. The 700°C post-deposition annealing was found to initiate a solid state transformation to the cubic (3C) ZnS crystal structure, and resulted in an average grain size of ∼250 nm at the surface of the annealed film.
Diffraction-contrast TEM, focused probe electron diffraction, and high-resolution X-ray diffraction were used to characterize the dislocation arrangements in a 16µm thick coalesced GaN film grown by MOVPE LEO. As is commonly observed, the threading dislocations that are duplicated from the template above the window bend toward (0001). At the coalescence plane they bend back to lie along  and thread to the surface. In addition, three other sets of dislocations were observed. The first set consists of a wall of parallel dislocations lying in the coalescence plane and nearly parallel to the substrate, with Burgers vector (b) in the (0001) plane. The second set is comprised of rectangular loops with b = 1/3  (perpendicular to the coalescence boundary) which originate in the coalescence boundary and extend laterally into the film on the (100). The third set of dislocations threads laterally through the film along the  bar axis with 1/3<110>-type Burgers vectors These sets result in a dislocation density of ∼109 cm−2. High resolution X-ray reciprocal space maps indicate wing tilt of ∼0.5º.
Diffraction-contrast TEM, focused probe electron diffraction, and high-resolution X-ray diffraction were used to characterize the dislocation arrangements in a 16[.proportional]m thick coalesced GaN film grown by MOVPE LEO. As is commonly observed, the threading dislocations that are duplicated from the template above the window bend toward (0001). At the coalescence plane they bend back to lie along  and thread to the surface. In addition, three other sets of dislocations were observed. The first set consists of a wall of parallel dislocations lying in the coalescence plane and nearly parallel to the substrate, with Burgers vector (b) in the (0001) plane. The second set is comprised of rectangular loops with b = 1/3 [11 20] (perpendicular to the coalescence boundary) which originate in the coalescence boundary and extend laterally into the film on the (1 100). The third set of dislocations threads laterally through the film along the [1 100] bar axis with 1/3<11 20>-type Burgers vectors These sets result in a dislocation density of ∼109 cm−2. High resolution X-ray reciprocal space maps indicate wing tilt of ∼0.5°.