Molecular-level Manipulation Technology for Low-k Dielectrics Controlling the Physical and Chemical Structures toward 32nm-node BEOLs

2008 ◽  
Vol 1079 ◽  
Author(s):  
Yoshihiro Hayashi

ABSTRACTLow-k materials in advanced interconnect modules are required not only to lower the parasitic capacitances, but also to have mechanical stability with damage-less interfaces. By plasma-polymerization (PP) process using ring-type siloxane precursor, a new self-organized porous SiOCH film is developed with preserving the original hexagonal silica-backbone structure, thus so called as a molecular-pore-stack (MPS) SiOCH film. The hydrocarbon-rich MPS film has high endurance to the process damages. A density-modulated MPS film is obtained with reinforced interfaces by plasma co-polymerization (PcP) process using not only the ring-type but also linear-type siloxane. Furthermore, an ultimate full low-k module with low-k silica-amorphous-carbon composite (SACC) cap, instead of high-k SiCN, is also obtained simply by the one-step deposition scheme. The modulated PcP process and the sophisticated molecular design of the precursor siloxane provides scaled-down interconnect modules with good mechanical strength and excellent dielectric reliability at a low manufacturing cost, applicable for 45/32/22nm-nodes ULSIs.

Author(s):  
C. C. Ahn ◽  
S. Karnes ◽  
M. Lvovsky ◽  
C. M. Garland ◽  
H. A. Atwater ◽  
...  

The bane of CCD imaging systems for transmission electron microscopy at intermediate and high voltages has been their relatively poor modulation transfer function (MTF), or line pair resolution. The problem originates primarily with the phosphor screen. On the one hand, screens should be thick so that as many incident electrons as possible are converted to photons, yielding a high detective quantum efficiency(DQE). The MTF diminishes as a function of scintillator thickness however, and to some extent as a function of fluorescence within the scintillator substrates. Fan has noted that the use of a thin layer of phosphor beneath a self supporting 2μ, thick Al substrate might provide the most appropriate compromise for high DQE and MTF in transmission electron microcscopes which operate at higher voltages. Monte Carlo simulations of high energy electron trajectories reveal that only little beam broadening occurs within this thickness of Al film. Consequently, the MTF is limited predominantly by broadening within the thin phosphor underlayer. There are difficulties however, in the practical implementation of this design, associated mostly with the mechanical stability of the Al support film.


2020 ◽  
Vol 71 (1) ◽  
pp. 192-200
Author(s):  
Anca-Luiza Stanila ◽  
Catalin Cristian Simota ◽  
Mihail Dumitru

Highlighting the sandy soil of Oltenia Plain calls for a better knowledge of their variability their correlation with major natural factors from each physical geography. Pedogenetic processes specific sandy soils are strongly influenced by nature parent material. This leads, on the one hand, climate aridity of the soil due to strong heating and accumulation of small water reserves, consequences emphasizing the moisture deficit in the development of the vegetation and favoring weak deflation, and on the other hand, an increase in mineralization organic matter. Relief under wind characteristic sandy land, soil formation and distribution has some particularly of flat land with the land formed on the loess. The dune ridges are less evolved soils, profile underdeveloped and poorly supplied with nutrients compared to those on the slopes of the dunes and the interdune, whose physical and chemical properties are more favorable to plant growth.Both Romanati Plain and the Blahnita (Mehedinti) Plain and Bailesti Plain, sand wind shaped covering a finer material, loamy sand and even loess (containing up to 26% clay), also rippled with negative effects in terms of overall drainage. Depending on the pedogenetic physical and geographical factors that have contributed to soil cover, in the researched were identified following classes of soils: protisols, cernisols, cambisols, luvisols, hidrisols and antrosols.Obtaining appropriate agricultural production requires some land improvement works (especially fitting for irrigation) and agropedoameliorative works. Particular attention should be paid to preventing and combating wind erosion.


2015 ◽  
Vol 52 (1) ◽  
pp. 76-80 ◽  
Author(s):  
Fábio Vieira TEIXEIRA ◽  
Paulo Gustavo KOTZE ◽  
Aderson Omar Mourão Cintra DAMIÃO ◽  
Sender Jankiel MISZPUTEN

ABSTRACT Biosimilars are not generic drugs. These are more complex medications than small molecules, with identical chemical structures of monoclonal antibodies that lost their patency over time. Besides identical to the original product at the end, the process of achieving its final forms differs from the one used in the reference products. These differences in the formulation process can alter final outcomes such as safety and efficacy of the drugs. Recently, a biosimilar of Infliximab was approved in some countries, even to the management of inflammatory bowel diseases. However, this decision was based on studies performed in rheumatologic conditions such as rheumatoid arthritis and ankylosing spondylitis. Extrapolation of the indications from rheumatologic conditions was done for Crohn’s disease and ulcerative colitis based on these studies. In this article, the authors explain possible different mechanisms in the pathogenesis between rheumatologic conditions and inflammatory bowel diseases, that can lead to different actions of the medications in different diseases. The authors also alert the gastroenterological community for the problem of extrapolation of indications, and explain in full details the reasons for being care with the use of biosimilars in inflammatory bowel diseases without specific data from trials performed in this scenario.


Membranes ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 221
Author(s):  
Rafał Tytus Bray ◽  
Katarzyna Jankowska ◽  
Eliza Kulbat ◽  
Aneta Łuczkiewicz ◽  
Aleksandra Sokołowska

The paper presents the results of research on the use of ultrafiltration, using membranes of 200 and 400 kDa separation, for disinfection of municipal treated wastewater. The research was conducted on a fractional technical scale using real municipal treated wastewater from two large wastewater treatment plants treating most of the wastewater over the one-million polycentric Gdańsk agglomeration (1.2 million inhabitants). UF 200 kDa and UF 400 kDa processes enabled further improvement of the physical and chemical parameters of treated wastewater. Total phosphorus (to below 0.2 mg/L–UF 200 kDa, 0.13 mg/L–UF 400 kDa) and turbid substances (to below 0.2 mg/L, both membranes) were removed in the highest degree. COD was reduced efficiently (to below 25.6 mgO2/L–UF 200 kDa, 26.8 mgO2/L–UF 400 kDa), while total nitrogen was removed to a small extent (to 7.12 mg/L–UF 200 kDa and 5.7 mg/L–UF 400 kDa. Based on the reduction of indicator bacteria; fecal coliforms including E. coli (FC) and fecal enterococci (FE) it was found that the ultrafiltration is an effective method of disinfection. Not much indicator bacterial were observed in the permeate after processes (UF 200 kDa; FC—5 CFU/L; FE—1 CFU/L and UF 400 kDa; FC—70 CFU/L; FE—10 CFU/L. However, microscopic analysis of prokaryotic cells and virus particles showed their presence after the application of both membrane types; TCN 3.0 × 102 cells/mL–UF 200 kDa, 5.0 × 103 cells/mL–UF 400 kDa, VP 1.0 × 105/mL. The presence of potentially pathogenic, highly infectious virus particles means that ultrafiltration cannot be considered a sufficient disinfection method for treated wastewater diverted for reuse or discharged from high load wastewater treatment plants to recreational areas. For full microbiological safety it would be advisable to apply an additional disinfection method (e.g., ozonation).


2021 ◽  
Author(s):  
Junzhen Ren ◽  
Pengqing Bi ◽  
Jianqi Zhang ◽  
Jiao Liu ◽  
Jingwen Wang ◽  
...  

Abstract Developing photovoltaic materials with simple chemical structures and easy synthesis still remains a major challenge in the industrialization process of organic solar cells (OSCs). Herein, an ester substituted poly(thiophene vinylene) derivative, PTVT-T, was designed and synthesized in very few steps by adopting commercially available raw materials. The ester groups on the thiophene units enable PTVT-T to have a planar and stable conformation. Moreover, PTVT-T presents a wide absorption band and strong aggregation effect in solution, which are the key characteristics needed to realize high performance in non-fullerene-acceptor (NFA)-based OSCs. We then prepared OSCs by blending PTVT-T with three representative fullerene- and NF-based acceptors, PC71BM, IT-4F and BTP-eC9. It was found that PTVT-T can work well with all the acceptors, showing great potential to match new emerging NFAs. Particularly, a remarkable power conversion efficiency of 16.20% is achieved in a PTVT-T:BTP-eC9-based device, which is the highest value among the counterparts based on PTV derivatives. This work demonstrates that PTVT-T shows great potential for the future commercialization of OSCs.


2021 ◽  
Vol 5 (1) ◽  
Author(s):  
Depeng Wang ◽  
Shufang Zhao ◽  
Ruiyang Yin ◽  
Linlin Li ◽  
Zheng Lou ◽  
...  

AbstractDiversified regulation of electrons have received much attention to realize a multi-functional transistor, and it is crucial to have a considerable control over the charge carriers in transistors. Ionic gel, as the dielectric material in transistors, facilitates a large capacitance, and high induced-carrier concentrations. This review presents the recent progress in ionic-gated transistors (IGTs) that have good mechanical stability as well as high physical and chemical stability. We first briefly introduce the various applications of IGTs in sensors, neuromorphic transistors, organic transistor circuits, and health detection. Finally, the future perspectives of IGTs are discussed and some possible solutions to the challenges are also proposed.


Polymers ◽  
2021 ◽  
Vol 13 (12) ◽  
pp. 1939
Author(s):  
Helyati Abu Hassan Shaari ◽  
Muhammad Mahyiddin Ramli ◽  
Mohd Nazim Mohtar ◽  
Norizah Abdul Rahman ◽  
Azizan Ahmad

Poly(methyl methacrylate) (PMMA) is a lightweight insulating polymer that possesses good mechanical stability. On the other hand, polyaniline (PANi) is one of the most favorable conducting materials to be used, as it is easily synthesized, cost-effective, and has good conductivity. However, most organic solvents have restricted potential applications due to poor mechanical properties and dispersibility. Compared to PANi, PMMA has more outstanding physical and chemical properties, such as good dimensional stability and better molecular interactions between the monomers. To date, many research studies have focused on incorporating PANi into PMMA. In this review, the properties and suitability of PANi as a conducting material are briefly reviewed. The major parts of this paper reviewed different approaches to incorporating PANi into PMMA, as well as evaluating the modifications to improve its conductivity. Finally, the polymerization condition to prepare PMMA/PANi copolymer to improve its conductivity is also discussed.


Cellulose ◽  
2017 ◽  
Vol 24 (8) ◽  
pp. 3513-3523 ◽  
Author(s):  
Zhouyang Xiang ◽  
Qingguo Liu ◽  
Yong Chen ◽  
Fachuang Lu

Author(s):  
Vladimir Tsirelson ◽  
Adam Stash

This work extends the orbital-free density functional theory to the field of quantum crystallography. The total electronic energy is decomposed into electrostatic, exchange, Weizsacker and Pauli components on the basis of physically grounded arguments. Then, the one-electron Euler equation is re-written through corresponding potentials, which have clear physical and chemical meaning. Partial electron densities related with these potentials by the Poisson equation are also defined. All these functions were analyzed from viewpoint of their physical content and limits of applicability. Then, they were expressed in terms of experimental electron density and its derivatives using the orbital-free density functional theory approximations, and applied to the study of chemical bonding in a heteromolecular crystal of ammonium hydrooxalate oxalic acid dihydrate. It is demonstrated that this approach allows the electron density to be decomposed into physically meaningful components associated with electrostatics, exchange, and spin-independent wave properties of electrons or with their combinations in a crystal. Therefore, the bonding information about a crystal that was previously unavailable for X-ray diffraction analysis can be now obtained.


Author(s):  
Raha Saremi ◽  
Nikolay Borodinov ◽  
Amine Mohamed Laradji ◽  
Suraj Sharma ◽  
Igor Luzinov ◽  
...  

Renewable nanocellulose materials received increased attention owing to their small dimensions, high specific surface area, high mechanical characteristics, biocompatibility, and compostability. Nanocellulose coatings are among many interesting applications of these materials to functionalize different by composition and structure surfaces, including plastics, polymer coatings, and textiles with broader applications from food packaging to smart textiles. Variations in porosity and thickness of nanocellulose coatings are used to adjust a load of functional molecules and particles into the coatings, their permeability, and filtration properties. Mechanical stability of nanocellulose coatings in a wet and dry state are critical characteristics for many applications. In this work, nanofibrillated and nanocrystalline cellulose coatings deposited on the surface of polymer films and textiles made of cellulose, polyester, and nylon are studied using atomic force microscopy, ellipsometry, and T-peel adhesion tests. Methods to improve coatings adhesion and stability using physical and chemical cross-linking with added polymers and polycarboxylic acids are analyzed in this study. The paper reports on the effect of the substrate structure and ability of nanocellulose particles to intercalate into the substrate on the coating adhesion.


Sign in / Sign up

Export Citation Format

Share Document