Electronic Devices and Semiconductor Manufacturing Commons^™

Influence Of Heat Treatment On The Behaviorof 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

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.

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

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.

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

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.

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.

Characterization Of Flexible Hybrid Electronics Using Stretchable Silver Ink And Ultra-Thin Silicon Die, Joshua A. Ledgerwood

Master's Theses

Flexible Hybrid Electronics (FHEs) offer many advantages to the future of wearable technology. By combining the dynamic performance of conductive inks, and the functionality of ultra-thinned, traditional IC technology, new FHE devices allow for development of applications previously excluded by relying on a specific type of electronics technology.

The characterization and reliability analysis of stretchable conductive inks paired with ultra-thin silicon die in theµm range was conducted. A silver based ink designed to be stretchable was screen printed on a TPU substrate and cured using box oven, conveyor convection oven, and photonic curing processes. Reliability tests were conducted including a …

Reduction In Recombination Current Density In Boron Doped Silicon Using Atomic Hydrogen, Matthew Garett Young

Graduate Theses and Dissertations

The solar industry has grown immensely in recent years and has reached a point where solar energy has now become inexpensive enough that it is starting to emerge as a mainstream electrical generation source. However, recent economic analysis has suggested that for solar to become a truly wide spread source of electricity, the costs still need to plummet by a factor of 8x. This demands new and innovative concepts to help lower such cost. In pursuit of this goal, this dissertation examines the use of atomic hydrogen to lessen the recombination current density in the boron doped region of n-type …

Direct Bandgap Cross-Over Point Of Ge1-YSnY Grown On Si Estimated Through Temperature-Dependent Photoluminescence Studies, Thomas R. Harris, Mee-Yi Ryu, Yung Kee Yeo, Buguo Wang, C. L. Senaratne

Faculty Publications

Epitaxial Ge_1-ySn_y (y = 0%–7.5%) alloys grown on either Si or Ge-buffered Si substrates by chemical vapor deposition were studied as a function of Sn content using temperature-dependent photoluminescence (PL). PL emission peaks from both the direct bandgap (Γ-valley) and the indirect bandgap (L-valley) to the valence band (denoted by E_D and EID, respectively) were clearly observed at 125 and 175 K for most Ge_1-ySn_y samples studied. At 300 K, however, all of the samples exhibited dominant E_D emission with either very weak or no measureable E_ID emission. At 10 K, …

Metal-Assisted Etching Of Silicon Molds For Electroforming, Ralu Divan, Dan Rosenthal '14, Karim Ogando, Leonidas E. Ocola, Daniel Rosenmann, Nicolaie Moldovan

Student Publications & Research

Ordered arrays of high-aspect-ratio micro/nanostructures in semiconductors stirred a huge scientific interest due to their unique one-dimensional physical morphology and the associated electrical, mechanical, chemical, optoelectronic, and thermal properties. Metal-assisted chemical etching enables fabrication of such high aspect ratio Si nanostructures with controlled diameter, shape, length, and packing density, but suffers from structure deformation and shape inconsistency due to uncontrolled migration of noble metal structures during etching. Hereby the authors prove that a Ti adhesion layer helps in stabilizing gold structures, preventing their migration on the wafer surface while not impeding the etching. Based on this finding, the authors demonstrate …

In-Situ Ellipsometry Characterization Of Anodically Grown Silicon Dioxide And Lithium Intercalation Into Silicon, Eric A. Montgomery

Department of Electrical and Computer Engineering: Dissertations, Theses, and Student Research

In this thesis, in-situ ellipsometry and electroanalytical investigations of two electrochemical processes are reported: including the formation of anodically grown silicon dioxide and the intercalation of lithium into silicon. Analysis of the ellipsometry data shows that the anodically grown silicon dioxide layer is uniform and has similar properties as thermally grown silicon dioxide. The lithium-ion intercalation data reveals non-uniform thin film formation, which requires further studies and development of appropriate ellipsometric optical models.

Advisers: Eva Schubert and Mathias Schubert

Low-Temperature Growth Of Inn On Si(100) By Femtosecond Pulsed Laser Deposition, M. A. Hafez, H. E. Elsayed-Ali

Electrical & Computer Engineering Faculty Publications

InN films were grown on Si(100) using femtosecond pulsed laser deposition. Laser induced breakdown of ammonia was used to generate atomic nitrogen for InN growth. An indium buffer layer was initially deposited on the Si substrate at low temperature followed by an InN intermediate layer. The crystal quality and surface morphology were investigated by reflection high-energy electron diffraction during growth and atomic force microscopy and x-ray diffraction after growth. The results showed that the In (2×1) initial buffer layer improved the quality of the InN film. High quality InN films were grown at a temperature of ∼350 °C.

Band Gap Engineering Of Two Dimensional Silicon Photonic Crystals By Oxidation And Oxide Etching, Makhin Thitsa

Electrical & Computer Engineering Theses & Dissertations

In this thesis a thorough analysis is presented on the effects of oxidation and oxide etching on the band structure of two dimensional silicon photonic crystals (2 D Si PC's). By using the plane wave expansion method (PWM), two structures of triangular lattice, namely, air cylinders embedded in a silicon background and silicon cylinders embedded in an air background are modeled. The thesis focuses on triangular lattice arrangement because for certain parameter values such a lattice can give rise to absolute band gap, which prohibits the propagation of either transverse electric (TE) or transverse magnetic (TM) polarizations.

During oxidation three …

Investigation Of Nanoporous Thin-Film Alumina Templates, Biswajit Das

Electrical & Computer Engineering Faculty Research

This paper presents the results of a systematic study of the fabrication of thin-film alumina templates on silicon and other substrates. Such templates are of significant interest for the low-cost implementation of semiconductor and metal nanostructure arrays. In addition, thin-film alumina templates on silicon have the potential for nanostructure integration with silicon electronics. Formation of thin-film alumina templates on silicon substrates was investigated under different fabrication conditions, and the dependence of pore morphology and pore formation rate on process parameters was evaluated. In addition, process conditions for improved pore size distribution and periodicity were determined. The template/silicon interface, important for …

Two-Dimensional Drift-Diffusion Simulations Of Silicon Avalanche Shaper (Sas) Devices For High Power Applications, Hamid Jalali

Electrical & Computer Engineering Theses & Dissertations

Silicon Avalanche Shaper devices have been projected as being important components of an inexpensive, semiconductor-based technology for high power switching applications. The primary advantage of this technology is that it is based on Silicon material which is easy to fabricate and has a well established processing technology. Unlike other high power technologies, the SAS devices do not rely on external optical triggering which eliminates the need for lasers and related optical circuitry.

The SAS based high power switching technology has been pioneered and tested by a Russian group. Though preliminary results have been very encouraging, the device reliability and its …

Influence Of Copper Doping On The Performance Of Optically Controlled Gaas Switches, St. T. Ko, V. K. Lakdawala, K. H. Schoenbach, M. S. Mazzola

Electrical & Computer Engineering Faculty Publications

The influence of the copper concentration in silicon-doped gallium arsenide on the photoionization and photoquenching of charge carriers was studied both experimentally and theoretically. The studies indicate that the compensation ratio (N_Cu/N_Si) is an important parameter for the GaAs:Si:Cu switch systems with regard to the turn-on and turn-off performance. The optimum copper concentration for the use of GaAs:Si:Cu as an optically controlled closing and opening switch is determined.

Nanosecond Optical Quenching Of Photoconductivity In A Bulk Gaas Switch, M. S. Mazzola, K. H. Schoenbach, V. K. Lakdawala, S. T. Ko

Electrical & Computer Engineering Faculty Publications

Persistent photoconductivity in copper-compensated, silicon-doped semi-insulating gallium arsenide with a time constant as large as 30 µs has been excited by sub-band-gap laser radiation of photon energy greater than 1 eV. This photoconductivity has been quenched on a nanosecond time scale by laser radiation of photon energy less than 1 eV. The proven ability to turn the switch conductance on and off on command, and to scale the switch to high power could make this semiconductor material the basis of an optically controlled pulsed-power closing and opening switch.