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Articles 31 - 60 of 67

Full-Text Articles in Electronic Devices and Semiconductor Manufacturing

Influence Of Impurities Of Refractory Elements On The Inefficiency Of Charge Transfer In Charged Communication Devices, Abdugafur T. Mamadalimov, Shakhrukh Kh. Daliev Jun 2019

Influence Of Impurities Of Refractory Elements On The Inefficiency Of Charge Transfer In Charged Communication Devices, Abdugafur T. Mamadalimov, Shakhrukh Kh. Daliev

Euroasian Journal of Semiconductors Science and Engineering

The influence of impurities of refractory elements on the inefficiency of charge transfer in charge-coupled devices is investigated. Found that the magnitude of the inefficiency of transfer  directly proportional to the density of surface States and the density of surface States in the CCD registers, with the resulting n losses n ≤ 0.1 depends on the type specially introduced impurities. It is shown that in CCD structures doped with impurities Ti, Zr and Hf relative to the control structures, the charge loss is greater, and in doped with impurities W and Mo, the charge loss is less.


Influence Of Rhodium And Iridium Impurity Atoms On The Capacitive Characteristics Of Si-Siо2 Structures, Khojakbar S. Daliev, Shakhriyor Kh. Yulchiev, Xotamjon J. Mansurov Jun 2019

Influence Of Rhodium And Iridium Impurity Atoms On The Capacitive Characteristics Of Si-Siо2 Structures, Khojakbar S. Daliev, Shakhriyor Kh. Yulchiev, Xotamjon J. Mansurov

Euroasian Journal of Semiconductors Science and Engineering

It was found that the doping of the semiconductor substrate with Rh and Ir atoms leads to the increase in the density of surface states at the Si – SiO2 interface. It is determined that the surface states, due to the presence of an impurity Rh and Ir are effective generation centers.


The Influence Of Γ -Irradiation On The Holographic Characteristics Of Chalcogenide Glassy Semiconductor, Zakirjan T. Аzamatov, Mira R. Bekchanova, Timur Z. Azamatov Jun 2019

The Influence Of Γ -Irradiation On The Holographic Characteristics Of Chalcogenide Glassy Semiconductor, Zakirjan T. Аzamatov, Mira R. Bekchanova, Timur Z. Azamatov

Euroasian Journal of Semiconductors Science and Engineering

Results of the research of holographic characteristics of chalcogenide glassy semiconductor films, under the influence of irradiation are presented. Found that in the range of radiation doses (roentgen) optical properties of (CGS) films and diffraction efficiency recorded holograms does not change. Also proved that the shelf life recorded holograms under certain conditions is 10 years or more.


Volt-Ampere Characteristics Of Mos Structures Al-Al2o3-P-Cdte-Mo – In The Forward Direction Of Current, Abatbay K. Uteniyazov, Kanatbay A. Ismailov, Fatima T. Srajatdinova Jun 2019

Volt-Ampere Characteristics Of Mos Structures Al-Al2o3-P-Cdte-Mo – In The Forward Direction Of Current, Abatbay K. Uteniyazov, Kanatbay A. Ismailov, Fatima T. Srajatdinova

Euroasian Journal of Semiconductors Science and Engineering

The results of studies of the direct branch of the current – voltage characteristic of the Al-Al2O3-p-CdTe-Mo structure with base thicknesses d ~ 8÷10 μm are presented. It was shown that, along with point defects and impurities, complex complexes participate in the recombination processes in the base of the structure under study. It was established that at low current densities in point of recombination processes point defects take part, and at high current densities, when the recombination rate reaches full saturation of U≈NR/τi, the recombination processes in the samples under study are determined by complex complexes within which the electrons …


The Principles Of Increasing The Sensitivity Of Transistor Structures To External Influences, Davron R. Djuraev, Abdulaziz V. Karimov, Dilbara M. Yodgorova, Akmal A. Turaev Jun 2019

The Principles Of Increasing The Sensitivity Of Transistor Structures To External Influences, Davron R. Djuraev, Abdulaziz V. Karimov, Dilbara M. Yodgorova, Akmal A. Turaev

Euroasian Journal of Semiconductors Science and Engineering

This article discusses a multifunctional sensor based on a field-effect transistor with a p-n-junction. The sensor allows to register temperature, light intensity, pressure with high level of sensitivity. At the same time, ensuring the sensitivity of the structure to external influences is practically solved due to constructive changes. Due to constructive solutions, the proposed sensor based on a field-effect transistor greatly exceeds the similar diode structures in sensitivity.


Optical Power Meter For Diagnostics Of Fiber-Optic Communication Lines And Digital Multimeter, Feruza A. Giyasova, B. Sh. Yuldashev, Ruslan G. Zakirov, Gulkhayo T. Murodillaeva Jun 2019

Optical Power Meter For Diagnostics Of Fiber-Optic Communication Lines And Digital Multimeter, Feruza A. Giyasova, B. Sh. Yuldashev, Ruslan G. Zakirov, Gulkhayo T. Murodillaeva

Euroasian Journal of Semiconductors Science and Engineering

A multifunctional optical power attenuation meter in fiber optic cables for widespread use is proposed in this article. The main feature of the proposed meter is the ability to perform of diagnostics of mechanical damage of fiber-optic communication lines and determine the attenuation degree of a signal in the fiber-optic path in the spectral ranges of 1270-1340 nm and 1520-1580 nm, as well as the measurement of voltage, current and resistance in electrical circuits. The possibility of using the meter for diagnostics of onboard fiber-optic communication lines is justified.


The Photoluminescence Spectra Of Powders Of Zinc Oxide With Laser Excitation, Ilyos A. Rakhmatullaev, Vladimir S. Gorelik, Abdulla K. Kurbonov Jun 2019

The Photoluminescence Spectra Of Powders Of Zinc Oxide With Laser Excitation, Ilyos A. Rakhmatullaev, Vladimir S. Gorelik, Abdulla K. Kurbonov

Euroasian Journal of Semiconductors Science and Engineering

The original sensitive method of research of the nanopowders based on use of laser excitation and a multichannel spectrometer is offered. The developed method can be used for the analysis of quality of a wide class of the powders on the basis of laser spectroscopy of secondary radiation.


Organic Photodiodes On The Basis Of Cotton Fiber/Polymer Composite, Jonibek J. Hamdamov, Anvar S. Zakirov, Abdugafur T. Mamadalimov Jun 2019

Organic Photodiodes On The Basis Of Cotton Fiber/Polymer Composite, Jonibek J. Hamdamov, Anvar S. Zakirov, Abdugafur T. Mamadalimov

Euroasian Journal of Semiconductors Science and Engineering

In this paper, we report a study on the optical and the electrical properties of pure cotton fibers (CF) from chemically surface- and morphology-modified samples coated with poly [2-methoxy-5-(2-ethylhexyloxy)- 1,4-phenylenevinylene] (MEH-PPV) polymer by using a dip-coating method. The efficiency of white light luminescence of cotton fibers coated with meh- MEH-PPV polymer increased and became much more intense in comparison with the luminescence of uncoated fibers and blue, green and red stripes were observed in the luminescence structure. The сurrent-voltage characteristic of sandwich-type devices consisting of successive layers of ITO (Indium doped tin oxide coated glass)-PEDOT-PSS (Poly (3,4-ethylenedioxythiophene)-Poly(styrenesulfonate)-CF/MEH-PPV-Ag showed that up …


Radiation And Convective Losses In The Heat Sink Channel Of Photovoltaic-Thermal System, Oskar F. Tukhfatullin, Ramizulla A. Muminov Jun 2019

Radiation And Convective Losses In The Heat Sink Channel Of Photovoltaic-Thermal System, Oskar F. Tukhfatullin, Ramizulla A. Muminov

Euroasian Journal of Semiconductors Science and Engineering

. The processes of heat transfer in the channel of a liquid photovoltaic/thermal system of a flat construction without forced circulation are considered. A method of calculating the heat transfer coefficients by radiation and convection, the Nusselt and Reynolds numbers for a given photovoltaic/thermal system was proposed. It was determined that the processes of convective heat transfer in a flat photovoltaic/thermal system installed in the territory of the Republic of Uzbekistan at an optimum angle of inclination equal to the geographical latitude of the place of operation should be considered as for parallel plates located at tilt angle not more …


Serial And Shuntable Resistance Of Cigs Solar Photo-Electric Module In The Conditions Of Real Solar Lighting At Various Temperatures, Rustam R. Kobulov, Nuriddin A. Matchanov, Omonboy K. Ataboev, Farrukh A. Akbarov Jun 2019

Serial And Shuntable Resistance Of Cigs Solar Photo-Electric Module In The Conditions Of Real Solar Lighting At Various Temperatures, Rustam R. Kobulov, Nuriddin A. Matchanov, Omonboy K. Ataboev, Farrukh A. Akbarov

Euroasian Journal of Semiconductors Science and Engineering

The current-voltage characteristics of the solar photovoltaic module, based on a thin-film polycrystalline semiconductor binary compound Cu(In, Ga)Se2, under real solar illumination (Prad=780 ± 30 W/m2), in the temperature range of 25 °C-50 °C, have been studied and the values of serial and shunt resistance are determined. It has been established that with increasing temperature, the magnitudes of the series and shunting resistance of the solar photovoltaic module decrease, which is most likely due to the modulation of the resistance of the n-CdS buffer front layer.


Influence Of Heat Treatment On The Behavior Of Deep Levels In Silicon Doped By Tungsten, Shokhrukh Kh. Daliev, Abdugofur T. Mamadalimov, Sayfullo S. Nasriddinov, Anifa D. Paluanova Jun 2019

Influence Of Heat Treatment On The Behavior Of Deep Levels In Silicon Doped By Tungsten, Shokhrukh Kh. Daliev, Abdugofur T. Mamadalimov, Sayfullo S. Nasriddinov, Anifa D. Paluanova

Euroasian Journal of Semiconductors Science and Engineering

By means of Deep Level Transient Spectroscopy the kinetics of the annealing of the levels of tungsten in silicon during heat treatment in the temperature range 150÷4000С was studied. It was found a non-monotonic change in the concentration of deep levels Ec-0.30 eV and Ec-0.39 eV under isothermal annealing: the concentrations of both levels at short times increase, then the concentration level of Ec-0.30 eV sharply decreases, and the reduction of the concentration of deep level Ec-0.39 eV is much slower.


Infrared Spectroscopy Of Silicon Doped By Stannum And Manganese, Sharifa B. Utamuradova, Ravshanbek M. Ergashev, Khusniddin J. Matchanov Jun 2019

Infrared Spectroscopy Of Silicon Doped By Stannum And Manganese, Sharifa B. Utamuradova, Ravshanbek M. Ergashev, Khusniddin J. Matchanov

Euroasian Journal of Semiconductors Science and Engineering

The processes of defect formation in silicon doped by tin and manganese and their interaction with uncontrolled impurities were studied by infrared spectroscopy.It was found that the presence of impurities of transition and isovalent elements leads to a technological decrease in the concentration of process impurities – oxygen and carbon. It was found that the introduction of manganese in Si leads to a strong decrease in the concentration of interstitial optically active oxygen Noopt: in rapidly cooled samples Si there is a decrease of Noopt by 50% compared to the original Si.


Structural Features Of The Solid Solution (Gaas)1-X-Y(Ge2)X(Znse)Y With Quantum Dots (0≤X≤0,17; 0≤Y≤0,14), Sirojiddin Z. Zainabidinov, Khatamjon J. Mansurov, Akramjon Y. Boboev, Hkushruy A. Makhmudov Jun 2019

Structural Features Of The Solid Solution (Gaas)1-X-Y(Ge2)X(Znse)Y With Quantum Dots (0≤X≤0,17; 0≤Y≤0,14), Sirojiddin Z. Zainabidinov, Khatamjon J. Mansurov, Akramjon Y. Boboev, Hkushruy A. Makhmudov

Euroasian Journal of Semiconductors Science and Engineering

X-ray diffraction studies showed that the resulting film has a sphalerite structure and is single-crystal with the (100) orientation. The lattice parameter of the film is af = 0.56697 nm. By atomic force microscope was shown the possibility of obtaining a semiconductor heterostructure with quantum dots by the method of liquid phase epitaxy.


Study Of The Morphological And Electrical Properties Of Films Of Solid Solution Znxsn1-Хse Obtained By The Method Of Cmbd, Kudrat M. Kuchkarov, Takhir M. Razykov, Bobur A. Ergashev, Rukhiddin T. Yuldoshov Jun 2019

Study Of The Morphological And Electrical Properties Of Films Of Solid Solution Znxsn1-Хse Obtained By The Method Of Cmbd, Kudrat M. Kuchkarov, Takhir M. Razykov, Bobur A. Ergashev, Rukhiddin T. Yuldoshov

Euroasian Journal of Semiconductors Science and Engineering

The ZnXSn1-XSe solid solution films were fabricated by the chemical molecular beam deposition (CMBD) method. The sources used were ZnSe and SnSe compounds of stoichiometric composition at the substrate temperature of 5600С. The morphological and electrophysical properties of the ZnXSn1-XSe solid solution films are investigated. Scanning electron microscope images showed that the grain sizes of the films are 8÷20 microns. The structural parameters of the obtained films are given. The electrical conductivity of the films was 15 ÷ 1 • 10-6 (Ohm·cm) -1 depending on the composition of the solid solution.


Capacitive Spectroscopy Of Defects In Semiconductors, Doped By Atoms Of Gadolinium, Shoakhriyor B. Norkulov, Khodjakbar S. Daliev, Makhmud Sh. Dehkanov, Uktam K. Erugliev Jun 2019

Capacitive Spectroscopy Of Defects In Semiconductors, Doped By Atoms Of Gadolinium, Shoakhriyor B. Norkulov, Khodjakbar S. Daliev, Makhmud Sh. Dehkanov, Uktam K. Erugliev

Euroasian Journal of Semiconductors Science and Engineering

The processes of formation of defects in silicon, doped by gadolinium are investigated by the method of DLTS. It is shown that in diffusion the introduction of Gd in the Si leads to the formation of deep levels with ionization energies Ec–0.23 eV, Ec–0.35 eV, Ec–0.41 eV and Ec–0.54 eV and a capture cross section of electrons n: 410-17cm-2, 210-15 cm2, 1.110-16 cm2 and 1.510-15 cm2, respectively, and in samples p-Si found only one level with Ev+0.32 eV.


Features The Generalities Of I-V Curve Formation In Mosfet With A Common Drain, Khayrulla K. Aripov, Akhmed M. Abdullayev, Shunkurjon T. Toshmatov Jun 2019

Features The Generalities Of I-V Curve Formation In Mosfet With A Common Drain, Khayrulla K. Aripov, Akhmed M. Abdullayev, Shunkurjon T. Toshmatov

Euroasian Journal of Semiconductors Science and Engineering

The results of theoretical and experimental studies of the generalities of current-voltage characteristics curve formation of metal-oxide-semiconductor transistors of the common drain are presented. The principal difference between input and output characteristics of the common drain from the analogical characteristics in the common source is shown. The source-gate and source characteristics of a metal-oxide-semiconductor transistor in the common drain are given. Combined families of source-gate and source characteristics of a metal-oxide-semiconductor transistor in the common source and drain are obtained.


Laser Testing Of Silicon Wafers, Zakirjan T. Azamatov, Ilya A. Kulagin, Kakhkhor P. Abdurakhmanov, Nigora A. N.A. Akbarova Jun 2019

Laser Testing Of Silicon Wafers, Zakirjan T. Azamatov, Ilya A. Kulagin, Kakhkhor P. Abdurakhmanov, Nigora A. N.A. Akbarova

Euroasian Journal of Semiconductors Science and Engineering

The possibility of detection of defects in silicon wafers by Fourier analysis of digital images obtained by laser introscopy is shown.


Electrophysical Properties Of Multilayered Photo-Sensitive Structures With Barriers Of Metal-Semiconductor, Abdulaziz V. Karimov, Dilbara M. Yodgorova, Feruza A. Giyasova, Oybek A. Abdulkhaev Apr 2019

Electrophysical Properties Of Multilayered Photo-Sensitive Structures With Barriers Of Metal-Semiconductor, Abdulaziz V. Karimov, Dilbara M. Yodgorova, Feruza A. Giyasova, Oybek A. Abdulkhaev

Euroasian Journal of Semiconductors Science and Engineering

The results of studies aimed at creating photodiode structures with a spectral range of 0.85÷0.9 µm and 1.31÷1.55 µm with an area of 3x4 mm2, which are obtained by successive vacuum deposition of cadmium sulfide and indium phosphide layers on a doped gallium arsenide substrate doped with oxygen with a specific resistance of 1∙107 Ohm∙sm. A distinctive feature of the obtained Au-vGaAs photodiode: O-nCdS-nInP-Au structures is the two-sided sensitivity and the presence of the amplification effect of the primary photocurrent (especially in the impurity region of the spectrum) and low dark current values (of the order of 10 nA) at …


Stabilizing Action Of Sodium Citrate When Receiving Silver Nanoparticles By The Method Of Chemical Restoration, Komil M. Mukimov, Shamil M. Sharipov, Tal’At S. Asilov, Asliddin Kh. Bakhriddinov Apr 2019

Stabilizing Action Of Sodium Citrate When Receiving Silver Nanoparticles By The Method Of Chemical Restoration, Komil M. Mukimov, Shamil M. Sharipov, Tal’At S. Asilov, Asliddin Kh. Bakhriddinov

Euroasian Journal of Semiconductors Science and Engineering

The results of the synthesis of colloidal silver nanoparticles by the method of chemical reduction by ascorbic acid in the presence of sodium citrate are presented. The use of ascorbic acid as a reducing agent allows the synthesis of nanoparticles at room temperature. This makes it possible to study the mechanisms of the stabilizing effect of sodium citrate in the process of obtaining nanoparticles.


Influence Of Ultrasonic Waves On The Photoelectric And Spectral Characteristics Of Si-Photodetectors, Abdumalik G. Gaibov, Kutbiddin I. Vakhobov Apr 2019

Influence Of Ultrasonic Waves On The Photoelectric And Spectral Characteristics Of Si-Photodetectors, Abdumalik G. Gaibov, Kutbiddin I. Vakhobov

Euroasian Journal of Semiconductors Science and Engineering

The paper considers the influence of ultrasonic fields on the photoelectric and spectral characteristics of diffusion Si-receivers of electromagnetic radiation. It was found that ultrasonic irradiation increases the lifetime, diffusion length of carriers and, as a consequence, increases the efficiency of collecting carriers on the electrical contacts of Si-receivers. As a result of these processes, an increase in the value of the short-circuit current is observed, which causes an increase in the open circuit voltage and the efficiency of such a diffusion Si-structure operating in the photo reformation mode.


Cascode Injection-Voltaic Transistor Fiber/Polymer Composite, Ziyoda Kh. Aripova, Shunkorjon T. Toshmatov Apr 2019

Cascode Injection-Voltaic Transistor Fiber/Polymer Composite, Ziyoda Kh. Aripova, Shunkorjon T. Toshmatov

Euroasian Journal of Semiconductors Science and Engineering

This paper developed injection-voltaic transistor presents. The results research of the V-I characteristic of cascode injection-voltaic transistor. It is shown that the proposed transistor operates stably at values of the reverse voltage collector-base 2-3 times higher than single transistors.


Features Of Diffusion In Epitaxial Cosi2 Films Grown On The Surface Of Fluorete Of Deep Levels In Silicon Doped By Tungsten, Bakhrom E. Egamberdiev, Shokhruh A. Sayfulloev Apr 2019

Features Of Diffusion In Epitaxial Cosi2 Films Grown On The Surface Of Fluorete Of Deep Levels In Silicon Doped By Tungsten, Bakhrom E. Egamberdiev, Shokhruh A. Sayfulloev

Euroasian Journal of Semiconductors Science and Engineering

The paper presents the results of the analysis of the epitaxial film CoSi2/Si/CaF2(100) grown by molecular beam epitaxy. It is proved that under certain conditions of heat treatment, so-called epitaxial silicides are formed on the crystal structure, which can play the role of conductive layers or metal coatings. The data obtained allow us to draw conclusions about the morphology of the film and the nature of diffusion in the CoSi2 layer.


Upgrading Photo - Thermal Battery For Increasing Efficiency In Use Hot Climate, Ramizulla A. Muminov, Mukhammad N. Tursunov, Khabibullo X. Sabirov, Sanjar K. Shokuchkorov Apr 2019

Upgrading Photo - Thermal Battery For Increasing Efficiency In Use Hot Climate, Ramizulla A. Muminov, Mukhammad N. Tursunov, Khabibullo X. Sabirov, Sanjar K. Shokuchkorov

Euroasian Journal of Semiconductors Science and Engineering

The experimental results of the modernization of photo – thermal battery of the new design of increased efficiency with thermal contact of the collector with the back surface of the photovoltaic battery (PhB) are presented. It is shown that the use of materials with a large reflection coefficient in the lateral plane of reflection, increasing accuracy of the operational guidance node on the Sun reducing the capacity of the heat collector provides an increase in power and uniformity of the temperature of the real surface of the PhB, which allows to increase the efficiency of the device.


The Method Of Sealing Of Temperature Sensors With Nickel Nanoclusters, Saifillo S. Nasriddinov, Shoira P. Usmanova, Shukhrat A. Ismoilov Apr 2019

The Method Of Sealing Of Temperature Sensors With Nickel Nanoclusters, Saifillo S. Nasriddinov, Shoira P. Usmanova, Shukhrat A. Ismoilov

Euroasian Journal of Semiconductors Science and Engineering

A method of sealing of temperature sensors to protect them from external factors is presented. The properties of the compound are also considered: high mechanical strength, water resistance, low moisture permeability, heat resistance, ozone resistance, high electrical strength.


Design Of Dc-Link Vscf Ac Electrical Power System For The Embraer 190/195 Aircraft, Eduardo Francis Carvalho Freitas, Nihad E. Daidzic Sep 2017

Design Of Dc-Link Vscf Ac Electrical Power System For The Embraer 190/195 Aircraft, Eduardo Francis Carvalho Freitas, Nihad E. Daidzic

Journal of Aviation Technology and Engineering

A proposed novel DC-Link VSCF AC-DC-AC electrical power system converter for Embraer 190/195 transport category airplane is presented. The proposed converter could replace the existing conventional system based on the CSCF IDGs. Several contemporary production airplanes already have VSCF as a major or backup source of electrical power. Problems existed with the older VSCF systems in the past; however, the switched power electronics and digital controllers have matured and can be now, in our opinion, safely integrated and replace existing constant-speed hydraulic transmissions powering CSCF AC generators. IGBT power transistors for medium-level power conversion and relatively fast efficient switching are …


Health Risks Caused By Wireless Technologies, Durreeshahwar Zafarahmed, Qurrat-Ul-Ain Zafarahmed Aug 2014

Health Risks Caused By Wireless Technologies, Durreeshahwar Zafarahmed, Qurrat-Ul-Ain Zafarahmed

Journal of Undergraduate Research at Minnesota State University, Mankato

There are many health issues related to the use of cellular phones, wireless local area networks, and other devices that emit electromagnetic radiation (EMR). Some of these systems have become a part of our daily lives and many of us are in direct or indirect contact for extended period of times with these devices. However, the general public is unaware of the health risks associated with the use of these devices. Our research covers studies done by individuals as well as organizations on the harmful effects on the health of people from these devices and their claims. We also present …


Is Tech M&A Value-Additive?, Ani Deshmukh Nov 2012

Is Tech M&A Value-Additive?, Ani Deshmukh

Undergraduate Economic Review

Given rising M&A deal volume across all high-tech subsectors, the ability to measure post-acquisition performance becomes critical. Despite this growth, the relevant academic literature is severely lacking (Kohers and Kohers 2000). Using an event-study approach, I find that acquirers and targets both realize statistically significant day-0 abnormal returns (1.23% [p<0.1] and 8.1% [p<0.01], respectively). As positive stock returns signal positive growth prospects in a semi-strong efficient market, AR regressions found that firms' technological relatedness, deal financing, purchase price premiums, and the relative book to market ratio, explained most variance. Overall, high-tech transactions are value-additive for both targets and acquirers.


Co-Polymers Of Furan With Pyrrole Or Thiophene: A Synthetic Study, Rose M. Mcconnell, Walter E. Godwin, Susan E. Baker, Kenya Powell, Martha Baskett, Amy Morara, Xiadong Ma Jan 2002

Co-Polymers Of Furan With Pyrrole Or Thiophene: A Synthetic Study, Rose M. Mcconnell, Walter E. Godwin, Susan E. Baker, Kenya Powell, Martha Baskett, Amy Morara, Xiadong Ma

Journal of the Arkansas Academy of Science

The use of conductive polymers as a substitute for metallic conductors and semiconductors has attracted much attention in the literature. In particular, aromatic heterocyclic polymers constitute an important class since they possess chemical and electrical stability in both the oxidized (doped) and neutral (undoped) state. Doping a polymer allows one to vary its electrical, mechanical, optical, and thermal properties. The properties of these polymers are promising for their many technological uses such as antistatic coatings, solar cells, and electronic devises. Polyfuran is among the least common heterocyclic polymers. Polyfuran has been reported to be much less stable that either polypyrrole …


The Need For Pfc Abatement In Semiconductor Manufacturing, Mohsen Manesh, Brian Kendrick Jan 2002

The Need For Pfc Abatement In Semiconductor Manufacturing, Mohsen Manesh, Brian Kendrick

Inquiry: The University of Arkansas Undergraduate Research Journal

Perfluorocompounds (PFCs) are highly stable chemical compounds used in two integral steps of semiconductor manufacturing: chemical vapor deposition (CVD) chambers and etch chambers. Unfortunately, PFCs are also greenhouse gases linked to global warming. This, combined with their long atmospheric lifetimes gives them global warming potentials much higher than C02 the principal greenhouse gas. In a series of voluntary agreements with the United States and other national governments, the worldwide semiconductor industry has set a goal of reducing PFC emissions to 90% of their 1995 levels. To reach this goal, researchers have explored four main methods of reduction: substitution of PFCs, …


Improved Methods For Electroplating Cadmium Sulfide Thin Films, Brandon Kemp, Robert Engelken, Arif Raza, Wasim Aleem, Imran Khan, Chris Barber Jan 1996

Improved Methods For Electroplating Cadmium Sulfide Thin Films, Brandon Kemp, Robert Engelken, Arif Raza, Wasim Aleem, Imran Khan, Chris Barber

Journal of the Arkansas Academy of Science

We report improved methods for electroplating cadmium sulfide (CMS) films. Aprevious problem was cracking/flaking of films deposited from organic solutions of elemental sulfur; attempts to improve adhesion via bath additives reduced grain size. Aqueous baths of thiosulfate ions yield cadmium-richness at low T temperatures (T), long deposition times, and/or poor bath stability. Developments in our work to be discussed include (1) plating ofuniform, adherent, and stoichiometric CdS from tetraethylene baths of CdCl 2 and elemental sulfur at T >70° C with minimal cracking/flaking, (2) improved uniformity/ adherence by use of CdL>, and (3) swept voltage methods in aqueous thiosulfate …