New Contact Etch Process for Embedded DRAM Applications

1999 ◽  
Vol 564 ◽  
Author(s):  
Chan-Lon Yang ◽  
Tong-Yu Chen ◽  
Keh-Ching Huang ◽  
Le-Tien Jung ◽  
Tsu-An Lin ◽  
...  
Keyword(s):  
Vertical Profile ◽  
High Selectivity ◽  
Active Regions ◽  
Complete Removal ◽  
Contact Processes ◽  
Process Chemistry ◽  
Layer Structures ◽  
New Process ◽  
Key Issues ◽  
Layer Contact

AbstractFor embedded DRAM (E-DRAM) devices with feature sizes of 0.25 µm and beyond, contact processes with low contact resistance and low junction leakage current are required. The contact etch process needs to etch through multi-layer structures with SiO2, SiON/SiN layers and stop on Ti-polycide gate and Ti-salicide active regions at the same time. The key issues include high selectivity to TiSix, vertical profile, complete removal of SiON/SiN cap layer and no polymer residues. In this paper, multi-layer contact etching without attacking TiSix is reported. Using new process chemistry, the new contact etch process has been demonstrated for the manufacturing of 0.25 µm E-DRAM and beyond.

New Process for Physico-Chemical Pretreatment of Dairy Effluents with Agricultural Use of Sludge Produced

1990 ◽  
Vol 22 (9) ◽  
pp. 93-100 ◽  
Author(s):  
Á Kárpáti ◽  
L. Bencze ◽  
J. Borszéki
Keyword(s):  
Field Experiments ◽  
Complete Removal ◽  
Grain Production ◽  
Molecular Weights ◽  
Physico Chemical ◽  
New Process ◽  
Agricultural Use ◽  
Removal Of Fat ◽  
Biological Methods ◽  
Dairy Effluents

A combined physico-chemical process is suitable for the effective pretreatment of dairy effluents, achieving almost complete removal of fat, and considerable reduction of protein content. The specific cost of COD removal using the process is only half or a third of that using aerobic biological methods. Depending on the chemicals used, further treatment or, in certain cases, agricultural utilization, of the sludge is possible. In addition, the components remaining in the effluent have low molecular weights, are easily degradable, and are very favourable as nutrients in municipal aerobic post-treatment. Investigation of the sludge showed that it did not contain any pathogen organisms and therefore its application on land is recommended. Laboratory and field experiments have shown that, with agricultural use of the sludge, increased plant growth and grain production were achieved.

scholarly journals Multitask Prediction of Site Selectivity in Aromatic C-H Functionalization Reactions

2019 ◽  
Author(s):  
Thomas J. Struble ◽  
Connor W. Coley ◽  
Klavs F. Jensen
Keyword(s):  
Neural Network ◽  
Drug Discovery ◽  
Convolutional Neural Network ◽  
High Selectivity ◽  
Accurate Prediction ◽  
Process Chemistry ◽  
Site Selectivity ◽  
Synthetic Routes ◽  
Validation Testing ◽  
Reciprocal Rank

Aromatic C-H functionalization reactions are an important part of the synthetic chemistry toolbox. Accurate prediction of site selectivity can be crucial for prioritizing target compounds and synthetic routes in both drug discovery and process chemistry. However, selectivity may be highly dependent on subtle electronic and steric features of the substrate. We report a generalizable approach to prediction of site selectivity that is accomplished using a graph-convolutional neural network for the multitask prediction of 123 C-H functionalization tasks. In an 80/10/10 training/validation/testing pseudo-time split of about 58,000 aromatic C-H functionalization reactions from the Reaxys database, the model achieves a mean reciprocal rank of 92%. Once trained, inference requires approximately 200 ms per compound to provide quantitative likelihood scores for each task. This approach and model allow a chemist to quickly determine which C-H functionalization reactions-if any-might proceed with high selectivity.

A wedgelet current system on Saturn

2020 ◽  
Author(s):  
Ruilong Guo ◽  
Zhonghua Yao ◽  
Benjamin Palmaerts ◽  
William Dunn ◽  
Nick Sergis ◽  
...  
Keyword(s):  
Magnetic Energy ◽  
Current System ◽  
Active Regions ◽  
Giant Planets ◽  
Local Times ◽  
Small Scale ◽  
Key Issues ◽  
Field Lines ◽  
Magnetosphere Of Saturn

<p>Magnetic energy and mass release processes are key issues to understand the magnetospheric dynamics and aurorae processes on planets. Recent studies reveal that rotationally driven processes at dayside on giant planets are much more important than we ever expected. The discovery on the dayside magnetodisc reconnection demonstrates that the rotation effect can overcome the solar wind compression to sufficiently stretch magnetic field lines at dayside (Guo et al., 2018, doi: 10.1038/s41550-018-0461-9). A long-standing small-scale reconnection process was also shown at all local times (Guo et al., 2019, doi: 10.3847/2041-8213/ab4429). Using Cassini in situ multiple instruments data, we here proposed a wedgelet current system governing the entire magnetosphere of Saturn, which can explain the observational phenomena of quasi-periodical electron energization recurrence and beads-like structure in the main aurora region. Localized active regions with finite azimuthal lengths in the magnetosphere were discretely and azimuthally distributed along the magnetodisc and rotated with the magnetosphere. The electron energizations recurred at the spacecraft are related to each active region that passed by. These studies reveal that the dynamics in magnetodisc are global effects on giant planets, which are not always restrained at nightside.</p>

Using the Background Signal of a Light Scattering Tool for I/I Photo Resist Strip Optimization and Monitoring

2012 ◽  
Vol 187 ◽  
pp. 113-116
Author(s):  
Sandip Halder ◽  
Rita Vos ◽  
Masayuki Wada ◽  
Martine Claes ◽  
Karine Kenis ◽  
...  
Keyword(s):  
Light Scattering ◽  
Technology Development ◽  
Semiconductor Devices ◽  
Background Signal ◽  
Feature Size ◽  
Continuous Decrease ◽  
New Process ◽  
Key Issues ◽  
Mere Existence ◽  
The Cost

With the continuous decrease of feature size of semiconductor devices new process related challenges must be overcome continuously. One of the key issues for technology development is to have the proper metrology in place to evaluate the myriad process steps fast and accurately. Sometimes the mere existence of a particular metrology is not enough because of cost and throughput issues. The goal of this paper is to show that simply by monitoring the background signal of a light scattering tool, certain process optimizations and monitoring can be done much faster while bringing down the cost significantly. We focus particularly on post I/I strip optimization in this paper.

scholarly journals 3D Modeling of the Cadastre and the Spatial Representation of Property

2021 ◽  
pp. 589-607
Author(s):  
Lin Li ◽  
Renzhong Guo ◽  
Shen Ying ◽  
Haizhong Zhu ◽  
Jindi Wu ◽  
...  
Keyword(s):  
Land Use ◽  
Spatial Data ◽  
Spatial Representation ◽  
Three Dimensional ◽  
Urban Land Use ◽  
Specific Reference ◽  
Modeling Technology ◽  
Layer Structures ◽  
Key Issues ◽  
Cadastral System

AbstractAn emerging technology, three-dimensional (3D) cadastres as extensions to the current parcel-based or two-dimensional (2D) cadastre, has been developed to meet the management of 3D urban land use and 3D properties. This chapter provides a brief review of the key issues of 3D cadastre and the spatial representation of ownership. In order to understand the importance of legislation for developing modeling technology for 3D property, the legislative context of ownership is addressed in specific reference to China. In light of spatial rights of land-use space, a 3D spatial model of property is presented in terms of polyhedra with four-layer structures. Being compatible with the existing 2D cadastre, this 3D spatial data structure is suitable as a hybrid cadastral system for 2D and 3D property and provides an available means to spatially represent 3D property with integrity. By analyzing the heterogeneity of the land space used for property, the ownership of condominiums with internal structure is addressed and spatial representation of ownership is presented by instantiation in a case study in China.

scholarly journals Multitask Prediction of Site Selectivity in Aromatic C-H Functionalization Reactions

2019 ◽  
Author(s):  
Thomas J. Struble ◽  
Connor W. Coley ◽  
Klavs F. Jensen
Keyword(s):  
Neural Network ◽  
Drug Discovery ◽  
Convolutional Neural Network ◽  
High Selectivity ◽  
Accurate Prediction ◽  
Process Chemistry ◽  
Site Selectivity ◽  
Synthetic Routes ◽  
Validation Testing ◽  
Reciprocal Rank

Aromatic C-H functionalization reactions are an important part of the synthetic chemistry toolbox. Accurate prediction of site selectivity can be crucial for prioritizing target compounds and synthetic routes in both drug discovery and process chemistry. However, selectivity may be highly dependent on subtle electronic and steric features of the substrate. We report a generalizable approach to prediction of site selectivity that is accomplished using a graph-convolutional neural network for the multitask prediction of 123 C-H functionalization tasks. In an 80/10/10 training/validation/testing pseudo-time split of about 58,000 aromatic C-H functionalization reactions from the Reaxys database, the model achieves a mean reciprocal rank of 92%. Once trained, inference requires approximately 200 ms per compound to provide quantitative likelihood scores for each task. This approach and model allow a chemist to quickly determine which C-H functionalization reactions-if any-might proceed with high selectivity.

scholarly journals CO2 sequestration by carbonation of olivine: a new process for optimal separation of the solids produced

2019 ◽  
Vol 8 (1) ◽  
pp. 480-487
Author(s):  
Laura Turri ◽  
Karine Gérardin ◽  
Hervé Muhr ◽  
François Lapicque ◽  
Alvaro Saravia ◽  
...  
Keyword(s):  
High Temperature ◽  
Co2 Sequestration ◽  
Previous Investigation ◽  
High Selectivity ◽  
Reaction Products ◽  
Direct Process ◽  
Optimal Separation ◽  
New Process ◽  
Rich Solution ◽  
Very High

Abstract CO2 sequestration by reaction with abundant, reactive minerals such as olivine has often been considered. The most straightforward, direct process consists in performing the reaction at high temperature and CO2 pressure, in view to producing silica, magnesium and iron carbonates and recovering the traces of nickel and chromite contained in the feedstock mineral. Most of direct processes were found to have an overall cost far larger than the CO2 removal tax, because of incomplete carbonation and insufficient properties of the reaction products. Similar conclusions could be drawn in a previous investigation with a tubular autoclave. An indirect process has been designed for high conversion of olivine and the production of separate, profitable products e.g. silica, carbonates, nickel salts, so that the overall process could be economically viable: the various steps of the process are described in the paper. Olivine particles (120 μm) can be converted at 81% with a low excess of acid within 3 h at 95°C. The silica quantitatively recovered exhibits a BET area over 400 m2 g-1, allowing valuable applications to be considered. Besides, the low contents of nickel cations could be separated from the magnesium-rich solution by ion exchange with a very high selectivity.

Use of A New High Speed Acrylate Deposition Process to Make Novel Multilayer Structures

1995 ◽  
Vol 382 ◽  
Author(s):  
David G. Shaw ◽  
Marc G. Langlois
Keyword(s):  
Vapor Deposition ◽  
High Speed ◽  
Vacuum Chamber ◽  
Inorganic Material ◽  
Deposition Process ◽  
Multilayer Structures ◽  
Layer Structures ◽  
Wide Range ◽  
New Process ◽  
Deposition Processes

ABSTRACTA new process has been developed to deposit acrylate thin films at speeds of 1500 ft/minute or higher. These films range in thickness from a few hundred Angstroms to a fewmicrons and are uniform in thickness to within 5%. They can vary in refractive index from 1.35 to 1.60 and have mechanical properties from very hard and abrasion resistantto very soft and flexible.The acrylate deposition process was originally developed for multilayer acrylate/aluminum capacitors where over 10,000 layer structures were produced[l]. The process is compatible with other vapor deposition processes such as sputtering, evaporation, and CVD. Both processes can take place at the same time in the same vacuum chamber toproduce various multilayer structures.This paper will discuss some of the features of this process and the associated equipment. It will present examples of the wide range of acrylate/acrylate, acrylate/metal, and acrylate/inorganic material structures that can be made. It will discuss various applications for these structures.

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