Structure of III-V oxides

1996 ◽  
Vol 54 ◽  
pp. 942-943
Author(s):  
Z. Liliental-Weber ◽  
M. Li ◽  
G. S. Li ◽  
C. Chang-Hasnain ◽  
E.R. Weber
Keyword(s):  
Integrated Circuits ◽  
Leakage Current ◽  
Elevated Temperatures ◽  
Impurity Diffusion ◽  
High Quality ◽  
Carrier Gas ◽  
Native Oxides ◽  
Lateral Oxidation ◽  
Algaas Layer

The lack of high-quality native oxides on the III-V compounds has hindered the development of III-V integrated circuits and optoelectronic technology. Recently it was shown that stable oxides can be formed in the III-V compounds rich in Al, such as AlxGa1-x As similarly as it was done in Si technology by the reaction of AlxGa1-x As with H2O vapor (in N2 carrier gas) at elevated temperatures (∼400−450°C). The high quality of these oxides was attributed to the formation of stable AlO(OH) and Al2O3 compounds. However, this conclusion was not definitive, since several Al rich compounds were proposed as well. In addition, it was never clarified whether the excess As created in this process has any role in the stabilization of these oxides, in reducing leakage current or in impurity diffusion. Moreover there is concern as to the quality of the oxide/GaAs interfaces created by lateral oxidation of an intermediate AlGaAs layer.

Study on Polishing Technology of GaAs Wafer

2012 ◽  
Vol 497 ◽  
pp. 200-204
Author(s):  
Qian Fa Deng ◽  
Tao Kong ◽  
Gan Li ◽  
Ju Long Yuan
Keyword(s):  
Integrated Circuits ◽  
Future Research ◽  
Polishing Process ◽  
High Quality ◽  
Gaas Wafer

GaAs are one of the most important semiconductor followed silicon, GaAs wafers are the mostly used substrates for fabricating integrated circuits (ICs). So the quality of ICs depends directly on the quality of GaAs wafers. A series of processes are required to manufacture high quality GaAs wafers. This paper reviews the literature on polishing technology of GaAs wafers, covering the history, summarizes the effects of slurry’s chemical and physical characters such as pH, oxidants, abrasive grit, velocity, and temperature in the polishing process. It also discusses some possible topics for future research.

scholarly journals Study of the Alcohol Quality Obtained by Fermentation of Highly Concentrated Grain Wine by Different Races of Yeast

2021 ◽  
Vol 4 (1) ◽  
pp. 158-168
Author(s):  
Svitlana Kovalchuk ◽  
Tetyanа Mudrak ◽  
Alina Nakonechna
Keyword(s):  
Ethyl Alcohol ◽  
Elevated Temperatures ◽  
Technology Development ◽  
Raw Materials ◽  
Alcoholic Beverages ◽  
Practical Significance ◽  
Yeast Fermentation ◽  
High Quality ◽  
Volatile Impurities

The topicality. Requirements for the quality of ethyl alcohol produced for further use in the production of alcoholic beverages are constantly increasing. This is due to the growing competition of producers of alcoholic beverages (improving the range and quality of products) and the revision of standards for products. New directions in the alcohol technology development require increasing the dry matter concentrations of the wort; fermentation at elevated temperatures and concentrations of alcohol in the brew; ensuring the reduction of the cost of alcohol by saving raw materials and energy resources. In such conditions, highly productive breeds of yeast with increased osmophilicity, thermotolerance and fermentation activity are required. Research related to the search for new strains producers of ethyl alcohol, and the technology development for highly concentrated mash from grain raw materials are relevant issues for the alcohol industry. Purpose and methods. Investigation of the alcoholic yeast races influence on the synthesis of metabolites during fermentation of highly concentrated wort from grain raw materials. For research methods common to the alcohol and alcoholic beverages have been used. Results. The influence of races of alcoholic yeast on the quality indicators of alcohol has been studied. It was found that the selected race of yeast S. cerevisiae DO-16 in the process of life synthesizes significantly fewer side metabolites compared to other studied races DO-11, K-81 and XII. The use of the selected race of S. cerevisiae DO-16 makes it possible to ferment highly concentrated wort from grain raw materials. It has been experimentally proved that at a concentration of DM concentration of the wort 28 %, the selected osmophilic strain of the yeast S. cerevisiae DO-16 provides regulated indicators of the hydrocarbon composition of mature brews and synthesizes up to 14.40 % vol. alcohol, respectively. To improve the qualitative sensory characteristics of ethanol, the possibility of metabolically adjusting the synthesis of volatile alcohol impurities using different races of alcoholic yeast was investigated. Conclusions and discussions. Scientific novelty lies in the selection race for the yeast fermentation of corn mash highly concentrated with reduced alcohol content related impurities. The influence of yeast race on the formation of alcohol metabolites has been studied. The practical significance of the obtained results lies in the industrial implementation of the selected race of alcoholic yeast for fermentation of highly concentrated wort from grain raw materials. Prospects for further research are the possibility of influencing the quality of alcohol as a raw material for high-quality alcoholic beverages. During the fermentation of wort from grain raw materials, the qualitative and quantitative composition of volatile impurities of alcohol largely depends on the race of alcoholic yeast. The results of research on the biosynthesis of volatile impurities of alcohol allow you to adjust the quality of alcohol for the production of high quality alcoholic beverages.

Chemical Mechanical Polishing of Silicon Wafers: Finite Element Analysis of Wafer Flatness

2005 ◽  
Author(s):  
X. H. Zhang ◽  
Z. J. Pei ◽  
Graham R. Fisher
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Integrated Circuits ◽  
Chemical Mechanical Polishing ◽  
Silicon Wafers ◽  
Mechanical Polishing ◽  
High Quality ◽  
Element Analysis ◽  
Polishing Pressure

Silicon is the primary semiconductor material used to fabricate integrated circuits. The quality of microchips depends directly on the quality of silicon wafers. A series of processes are required to manufacture the high-quality silicon wafers. Chemical mechanical polishing is a necessary step to achieve the required wafer flatness. In this paper, a finite element analysis has been conducted to study the effects of influencing factors (including Young’s modulus and Poisson’s ratio of the polishing pad, thickness of the pad, and polishing pressure) on the wafer flatness.

Scanning Electron Microscopy in Hybrid Microelectronics

1976 ◽  
Vol 34 ◽  
pp. 456-457
Author(s):  
S. Khadpe ◽  
R. Faryniak
Keyword(s):  
Integrated Circuits ◽  
Thick Film ◽  
Integrated Circuit ◽  
Failure Modes ◽  
Three Dimensional ◽  
Circuit Components ◽  
Hybrid Microcircuit ◽  
Electrical Connections ◽  
Scanning Electron

The Scanning Electron Microscope (SEM) is an important tool in Thick Film Hybrid Microcircuits Manufacturing because of its large depth of focus and three dimensional capability. This paper discusses some of the important areas in which the SEM is used to monitor process control and component failure modes during the various stages of manufacture of a typical hybrid microcircuit.Figure 1 shows a thick film hybrid microcircuit used in a Motorola Paging Receiver. The circuit consists of thick film resistors and conductors screened and fired on a ceramic (aluminum oxide) substrate. Two integrated circuit dice are bonded to the conductors by means of conductive epoxy and electrical connections from each integrated circuit to the substrate are made by ultrasonically bonding 1 mil aluminum wires from the die pads to appropriate conductor pads on the substrate. In addition to the integrated circuits and the resistors, the circuit includes seven chip capacitors soldered onto the substrate. Some of the important considerations involved in the selection and reliability aspects of the hybrid circuit components are: (a) the quality of the substrate; (b) the surface structure of the thick film conductors; (c) the metallization characteristics of the integrated circuit; and (d) the quality of the wire bond interconnections.

Structural changes in silicon-on-insulator material during post-implantation annealing

1986 ◽  
Vol 44 ◽  
pp. 736-737
Author(s):  
C. O. Jung ◽  
S. J. Krause ◽  
S.R. Wilson
Keyword(s):  
Integrated Circuits ◽  
Oxide Layer ◽  
High Speed ◽  
Structural Changes ◽  
Device Fabrication ◽  
Silicon On Insulator ◽  
High Quality ◽  
Radiation Hardened ◽  
Post Implantation ◽  
Very High

Silicon-on-insulator (SOI) structures have excellent potential for future use in radiation hardened and high speed integrated circuits. For device fabrication in SOI material a high quality superficial Si layer above a buried oxide layer is required. Recently, Celler et al. reported that post-implantation annealing of oxygen implanted SOI at very high temperatures would eliminate virtually all defects and precipiates in the superficial Si layer. In this work we are reporting on the effect of three different post implantation annealing cycles on the structure of oxygen implanted SOI samples which were implanted under the same conditions.

Influence of technology parameters of free-cutting steel continuous casting on the billet internal structure

2020 ◽  
Vol 76 (2) ◽  
pp. 139-142
Author(s):  
A. T. Kunakbaeva ◽  
A. M. Stolyarov ◽  
M. V. Potapova
Keyword(s):  
Regression Analysis ◽  
Continuous Casting ◽  
Internal Structure ◽  
Sulfur Content ◽  
Manganese Content ◽  
High Quality ◽  
Correlation And Regression Analysis ◽  
Cutting Steel ◽  
Continuously Cast

Free-cutting steel gains specific working properties thanks to the high content of sulfur and phosphorus. These elements, especially sulfur, have a rather high tendency to segregation. Therefore, segregation defects in free-cutting steel continuously cast billets can be significantly developed. The aim of the work was to study the influence of the chemical composition of freecutting steel and casting technological parameters on the quality of the macrostructure of continuously cast billets. A metallographic assessment of the internal structure of cast metal made of free-cutting steel and data processing by application of correlation and regression analysis were the research methods. The array of production data of 43 heats of free-cutting steel of grade A12 was studied. Steel casting on a five-strand radial type continuous casting machine was carried out by various methods of metal pouring from tundish into the molds. Metal of 19 heats was poured with an open stream, and 24 heats – by a closed stream through submerged nozzles with a vertical hole. High-quality billets had a cross-sectional size of 150×150 mm. The macrostructure of high-quality square billets made of free-cutting steel of A12 grade is characterized by the presence of central porosity, axial segregation and peripheral point contamination, the degree of development of which was in the range from 1.5 to 2.0 points, segregation cracks and strips – about 1.0 points. In the course of casting with an open stream, almost all of these defects are more developed comparing with the casting by a closed stream. As a result of correlation and regression analysis, linear dependences of the development degree of segregation cracks and strips both axial and angular on the sulfur content in steel and on the ratio of manganese content to sulfur content were established. The degree of these defects development increases with growing of sulfur content in steel of A12 grade. These defects had especially strong development when sulfur content in steel was of more than 0.10%. To improve the quality of cast metal, it is necessary to have the ratio of the manganese content to the sulfur content in the metal more than eight.

Experience of clinical testing of personal telemedicine system ‘Obereg’ for remote monitoring of patients in intensive care units

2020 ◽  
pp. 52-58 ◽  
Author(s):  
A. A. Eryomenko ◽  
N. V. Rostunova ◽  
S. A. Budagyan ◽  
V. V. Stets
Keyword(s):  
Intensive Care ◽  
Intensive Care Units ◽  
Remote Monitoring ◽  
Clinical Testing ◽  
Transportation Of Patients ◽  
High Quality ◽  
Telemedicine System ◽  
Accuracy Of Measurements ◽  
Hospital Equipment

The experience of clinical testing of the personal telemedicine system ‘Obereg’ for remote monitoring of patients at the intensive care units of leading Russian clinics is described. The high quality of communication with the remote receiving devices of doctors, the accuracy of measurements, resistance to interference from various hospital equipment and the absence of its own impact on such equipment were confirmed. There are significant advantages compared to stationary patient monitors, in particular, for intra and out-of-hospital transportation of patients.

METHODOLOGICAL ASPECTS OF VISUALIZATION OF CORONARY ARTERIES WITH TRANSTHORACIC ECHOCARDIOGRAPHY

2018 ◽  
pp. 26-35
Author(s):  
Z. A. Agaeva ◽  
K. B. Baghdasaryan
Keyword(s):  
Blood Flow ◽  
Coronary Blood Flow ◽  
Coronary Arteries ◽  
Transthoracic Echocardiography ◽  
Second Harmonic ◽  
Anatomic Reconstruction ◽  
High Quality ◽  
Acoustic Window ◽  
Methodological Aspects

The transthoracic echocardiography made by multifrequency probes with support of the mode of the second harmonic imaging, is a competitive method for visualization of the main coronary arteries and allows to estimate coronary blood flow with high quality. Of course, the method has considerable restrictions, most important of which is the low spatial resolution of a method, due to small acoustic window. Because of this the transthoracic visualization of coronary arteries perhaps will not become the leading method of anatomic reconstruction of separately taken coronary artery and especially all coronary arteries system. However uniqueness and indisputable advantage of this method is an opportunity to noninvasively estimate a coronary blood flow both once, and in dynamics.

Estimates on poverty in Russia and the additional measures to reduce it at the regional level

2020 ◽  
Vol 18 (4) ◽  
pp. 739-752 ◽  
Author(s):  
R.M. Sadykov
Keyword(s):  
Poverty Rate ◽  
Regional Level ◽  
Living Standards ◽  
Standard Of Living ◽  
High Quality ◽  
Social Standard ◽  
Republic Of Bashkortostan ◽  
The Republic ◽  
Sociological Studies

Subject. This article deals with the issues of social justice and a high quality of life, creating favorable economic and social conditions. Objectives. The article aims to assess the rate and changes in poverty in Russia and the Republic of Bashkortostan and develop complementary measures to reduce it. Methods. For the study, I used the methods of logical, comparative, economic and statistical analyses, the results of sociological studies, and official statistics. Results. The article highlights additional measures to reduce poverty in the region, including the establishment of a minimum social standard of living in each particular region that determines the poverty rate. Conclusions. Various factors, such as economic sanctions, economic slowdowns, territorial and regional imbalances, lead to living standards decline and poverty rise.

SCIENTIFIC BASIS OF POSTGRADUATE TRAINING FOR OFFICER WORKING ETHNIC AFFAIRS USING STATE BUDGET IN THE PERIOD OF 2018 – 2025

2017 ◽  
Author(s):  
La Duc Minh ◽  
Nguyen Thi Hao ◽  
Vu Thi Thuy
Keyword(s):  
Economic Development ◽  
Ethnic Groups ◽  
Human Resource ◽  
Postgraduate Training ◽  
Scientific Basis ◽  
National Defense ◽  
High Quality ◽  
State Budget ◽  
International Integration

Ethnic affairs play an important role in socio of ethnic groups’ solidarity, assurance of security and national defense stability. In -economic development, maintenanceorder to improve the quality of ethnic affairs, it is practical to carry out postgraduate training of officer implementing ethnic affairs using state budget with the aim of encouraging and enhancing officer quality to satisfy high-quality human resource in international integration.

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