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Nano Research Feb 2023Inorganic perovskite wafers with good stability and adjustable sizes are promising in X-ray detection but the high synthetic temperature is a hindrance. Herein, dimethyl...
UNLABELLED
Inorganic perovskite wafers with good stability and adjustable sizes are promising in X-ray detection but the high synthetic temperature is a hindrance. Herein, dimethyl sulfoxide (DMSO) is used to prepare the CsPbBr micro-bricks powder at room temperature. The CsPbBr powder has a cubic shape with few crystal defects, small charge trap density, and high crystallinity. A trace amount of DMSO attaches to the surface of the CsPbBr micro-bricks via Pb-O bonding, forming the CsPbBr-DMSO adduct. During hot isostatic processing, the released DMSO vapor merges the CsPbBr micro-bricks, producing a compact and dense CsPbBr wafer with minimized grain boundaries and excellent charge transport properties. The CsPbBr wafer shows a large mobility-lifetime (μτ) product of 5.16 × 10 cm·V, high sensitivity of 14,430 μC·Gy·cm, low detection limit of 564 nGy·s, as well as robust stability in X-ray detection. The results reveal a novel strategy with immense practical potential pertaining to high-contrast X-ray detection.
ELECTRONIC SUPPLEMENTARY MATERIAL
Supplementary material (further details of the characterization, SEM images, AFM images, KPFM images, schematic illustration, XRD patterns, XPS spectra, FTIR spectra, UPS spectra, and stability tests) is available in the online version of this article at 10.1007/s12274-023-5487-3.
PubMed: 37359075
DOI: 10.1007/s12274-023-5487-3 -
Scientific Reports Jan 2024Room temperature wafer bonding is a desirable approach for the packaging and assembly of diverse electronic devices. The formation of [Formula: see text] layer at the...
Room temperature wafer bonding is a desirable approach for the packaging and assembly of diverse electronic devices. The formation of [Formula: see text] layer at the bonding interface is crucial for a reliable wafer bonding as represented by conventional bonding techniques such as hydrophilic bonding and glass frit bonding. This paper reports a novel concept of room temperature wafer bonding based on the conversion of polysilazane to [Formula: see text] at the bonding interface. As polysilazane is converted to [Formula: see text] by hydrolysis, in this work, adsorbed water is introduced to the bonding interface by plasma treatment, thereby facilitating the formation of [Formula: see text] at the wafer bonding interface. The experimental results indicate that the adsorbed water from the plasma treatment diffuses into the polysilazane layer and facilitates its hydrolysis and conversion. The proposed method demonstrates the successful wafer bonding at room temperature with high bond strength without interfacial voids. This technique will provide a new approach of bonding wafers at room temperature for electronics packaging.
PubMed: 38218732
DOI: 10.1038/s41598-024-51800-6 -
Pharmaceuticals (Basel, Switzerland) Dec 2022Curcumin is the main active constituent in turmeric, and it is one of the biopolyphenolic compounds. A cumulative body of research supports the use of curcumin in the...
Curcumin is the main active constituent in turmeric, and it is one of the biopolyphenolic compounds. A cumulative body of research supports the use of curcumin in the treatment of wounds, yet poor water solubility and lack of therapeutic dose determination hamper its use for this therapeutic purpose. This work aimed at preparing novel curcumin wafer dressings to provide a favorable environment for wound healing. Hybrid synthetic (PVA, PVP, HPMC, and CMC) and biodegradable (sodium alginate and dextran) polymers were employed to prepare wafer dressings loaded with incremental three doses (2, 10, and 20 mg) of curcumin per a wafer dressing. The solvent casting method was used to prepare the dressings. Dimension, surface pH, mechanical properties, DSC, FTIR, XRD, erosion time, and in vitro release were studied. Skin wound healing assay was studied in Wistar albino rats. Six curcumin-loaded wafers were successfully prepared with good mechanical properties. Curcumin was dispersed in an amorphous/molecular form, as evidenced by thermal (DSC) and spectral (FTIR and XRD) analyses. Prolonged curcumin release (>24 h) was recorded for F6 (10 mg curcumin) and F7 (20 mg curcumin). Wound healing rate constants and time for 50% wound closure (T1/2) were estimated from a semi-log wound diameter versus time curve. A superior healing rate (up to 3-fold faster) was recorded for curcumin-loaded wafer dressings containing 10 mg (F6) with T1/2 of 7 days compared to 20 days for the placebo-treated group. These results warrant using the selected curcumin-loaded wafer dressing for safer and faster wound closure.
PubMed: 36678535
DOI: 10.3390/ph16010038 -
Materials (Basel, Switzerland) Apr 2022Glass frit bonding is a widely used technology to cap and seal micro-electromechanical systems on the wafer level using a low melting point glass. Screen printing is the...
Glass frit bonding is a widely used technology to cap and seal micro-electromechanical systems on the wafer level using a low melting point glass. Screen printing is the main method to apply glass frit paste on wafers. Screen printing of glass frit paste is usually performed on less sensitive, less critical wafers, normally the capping wafer, because screen printing is a rough process involving the mechanical contact of the screen printing mesh and the wafer. However, for some applications in which contactless patterning of glass frit materials on the device wafers are preferred (e.g., 3D topographies, micro-lens and optics integration) jet dispensing could be a promising approach. Consequently, in this study, wafer-level jetting of glass frit materials on silicon wafers was proposed and investigated. The jetting parameters such as jetting distance, power and temperature were optimized for a glass frit paste. Additionally, the effect of jetted pitch size on the bond-line thickness was assessed. The wafers with jetted glass frit pastes were conclusively bonded in low vacuum and characterized. As a single-step (non-contact) additive approach, the jet printing of glass frit was revealed to be a straightforward, cost-effective and flexible approach with several implications for hermetic packaging.
PubMed: 35454479
DOI: 10.3390/ma15082786 -
Mathematical Biosciences and... May 2023The semiconductor manufacturing industry relies heavily on wafer surface defect detection for yield enhancement. Machine learning and digital image processing...
The semiconductor manufacturing industry relies heavily on wafer surface defect detection for yield enhancement. Machine learning and digital image processing technologies have been used in the development of various detection algorithms. However, most wafer surface inspection algorithms are not be applied in industrial environments due to the difficulty in obtaining training samples, high computational requirements, and poor generalization. In order to overcome these difficulties, this paper introduces a full-flow inspection method based on machine vision to detect wafer surface defects. Starting with the die image segmentation stage, where a die segmentation algorithm based on candidate frame fitting and coordinate interpolation is proposed for die sample missing matching segmentation. The method can segment all the dies in the wafer, avoiding the problem of missing dies splitting. After that, in the defect detection stage, we propose a die defect anomaly detection method based on defect feature clustering by region, which can reduce the impact of noise in other regions when extracting defect features in a single region. The experiments show that the proposed inspection method can precisely position and segment die images, and find defective dies with an accuracy of more than 97%. The defect detection method proposed in this paper can be applied to inspect wafer manufacturing.
PubMed: 37501422
DOI: 10.3934/mbe.2023526 -
Nanomaterials (Basel, Switzerland) Nov 2022Recently, the uniformity in the wafer edge area that is normally abandoned in the fabrication process has become important for improving the process yield. The wafer...
Recently, the uniformity in the wafer edge area that is normally abandoned in the fabrication process has become important for improving the process yield. The wafer edge structure normally has a difference of height between wafer and electrode, which can result in a sheath bend, distorting important parameters of the etch, such as ionic properties, resulting in nonuniform etching. This problem nowadays is resolved by introducing the supplemented structure called a focus ring on the periphery of the wafer. However, the focus ring is known to be easily eroded by the bombardment of high-energy ions, resulting in etch nonuniformity again, so that the focus ring is a consumable part and must be replaced periodically. Because of this issue, there are many simulation studies being conducted on the correlation between the sheath structural characteristics and materials of focus rings to find the replacement period, but the experimental data and an analysis based on this are not sufficient yet. In this study, in order to experimentally investigate the etching characteristics of the wafer edge area according to the sheath structure of the wafer edge, the etching was performed by increasing the wafer height (thickness) in the wafer edge area. The result shows that the degree of tilt in the etch profile at the wafer edge and the area where the tilt is observed severely are increased with the height difference between the wafer and electrode. This study is expected to provide a database for the characteristics of the etching at the wafer edge and useful information regarding the tolerance of the height difference for untilted etch profile and the replacement period of the etch ring.
PubMed: 36432249
DOI: 10.3390/nano12223963 -
ACS Nano Feb 2021Graphene and related materials can lead to disruptive advances in next-generation photonics and optoelectronics. The challenge is to devise growth, transfer and...
Graphene and related materials can lead to disruptive advances in next-generation photonics and optoelectronics. The challenge is to devise growth, transfer and fabrication protocols providing high (≥5000 cm V s) mobility devices with reliable performance at the wafer scale. Here, we present a flow for the integration of graphene in photonics circuits. This relies on chemical vapor deposition (CVD) of single layer graphene (SLG) matrices comprising up to ∼12000 individual single crystals, grown to match the geometrical configuration of the devices in the photonic circuit. This is followed by a transfer approach which guarantees coverage over ∼80% of the device area, and integrity for up to 150 mm wafers, with room temperature mobility ∼5000 cm V s. We use this process flow to demonstrate double SLG electro-absorption modulators with modulation efficiency ∼0.25, 0.45, 0.75, 1 dB V for device lengths ∼30, 60, 90, 120 μm. The data rate is up to 20 Gbps. Encapsulation with single-layer hexagonal boron nitride (hBN) is used to protect SLG during plasma-enhanced CVD of SiN, ensuring reproducible device performance. The processes are compatible with full automation. This paves the way for large scale production of graphene-based photonic devices.
PubMed: 33522789
DOI: 10.1021/acsnano.0c09758 -
Micromachines Aug 2023Detecting and classifying defects on unpatterned wafers is a key part of wafer front-end inspection. Defect inspection schemes vary depending on the type and location of...
Detecting and classifying defects on unpatterned wafers is a key part of wafer front-end inspection. Defect inspection schemes vary depending on the type and location of the defects. In this paper, the structure of the prototype is designed to meet the requirements of wafer surface and edge defect inspection. This prototype has four inspection channels: scattering, reflection, phase, and contour, with two working conditions: surface and edge inspection. The key structure of the prototype was simulated using Ansys. The simulation results show that the maximum deformation of the optical detection subsystem is 19.5 μm and the fundamental frequency of the prototype is 96.9 Hz; thus, these results meet the requirements of optical performance stability and structural design. The experimental results show that the prototype meets the requirements of the inspection sensitivity better than 200 nm equivalent PSL spherical defects.
PubMed: 37630105
DOI: 10.3390/mi14081568 -
PloS One 2019The aim of this study was to investigate an accuracy of modified CAD/CAM generated wafers for orthognathic surgery. A total of 20 patients who had undergone bimaxillary...
The aim of this study was to investigate an accuracy of modified CAD/CAM generated wafers for orthognathic surgery. A total of 20 patients who had undergone bimaxillary orthognathic surgery were included and divided into two groups: A conventional CAD/CAM generated intermediate wafer and a modified CAD/CAM generated intermediate wafer. A series of CT images were taken to compare the virtual simulations with the actual postoperative outcomes(1 month after surgery). In conventional group, the mean difference of maxillary position between virtual simulation models and postoperative results was 0.78mm and overall average error within 1mm was observed in 66.4% of the repositioned maxilla. In modified group, the mean difference was 0.77mm and overall average error within 1mm was observed in 68.3%. There were no significant statistic differences between two groups in maxillary position. This study suggests that the CAD/CAM generated wafer provides excellent accuracy. The modified CAD/CAM wafer was only comparable to conventional design in accuracy and it cannot guarantee the superior precision. However, the modified design could be beneficial in cases with unstable condylar position or for inexperienced surgeons.
Topics: Adolescent; Adult; Cephalometry; Computer Simulation; Computer-Aided Design; Female; Humans; Image Processing, Computer-Assisted; Imaging, Three-Dimensional; Male; Maxilla; Orthognathic Surgical Procedures; Patient Care Planning; Postoperative Period; Printing, Three-Dimensional; Reproducibility of Results; Surgery, Computer-Assisted; Tomography, X-Ray Computed; Young Adult
PubMed: 31095627
DOI: 10.1371/journal.pone.0216945 -
Micromachines Jul 2022Heterogeneous integration of micro-electro mechanical systems (MEMS) and complementary metal oxide semiconductor (CMOS) integrated circuits (ICs) by 3D stacking or wafer...
Heterogeneous integration of micro-electro mechanical systems (MEMS) and complementary metal oxide semiconductor (CMOS) integrated circuits (ICs) by 3D stacking or wafer bonding is an emerging approach to advance the functionality of microdevices. Aluminum (Al) has been of interest as one of the wafer bonding materials due to its low cost and compatibility with CMOS processes. However, Al wafer bonding typically requires a high temperature of 450 °C or more due to the stable native oxide which presents on the Al surface. In this study, a wafer bonding technique for heterogeneous integration using electroplated Al bonding frame is demonstrated. The bonding mechanism relies on the mechanical deformation of the electroplated Al bonding frame through a localized bonding pressure by the groove structures on the counter wafer, i.e., press marking. The native oxide on the surface was removed and a fresh Al surface at the bonding interface was released through such a large mechanical deformation. The wafer bonding was demonstrated at the bonding temperatures of 250-450 °C. The influence of the bonding temperature to the quality of the bonded substrates was investigated. The bonding shear strength of 8-100 MPa was obtained, which is comparable with the other Al bonding techniques requiring high bonding temperature.
PubMed: 36014143
DOI: 10.3390/mi13081221