Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 20 of 333 for “"Dopant"”.
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Elucidating Dopant Migration Mechanism for the Controlled Dopant Locations/Distribution within Core/Shell Nanocrystals
… for use in optical and electronic devices. Dopant ions have been found to diffuse/migrate throughout solid materials when the thermal energy of the system is elevated above a temperature boundary allowing the cations and anions within a system to move freely. Nanomaterials such as …
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Dopant Incorporation in InAs/GaAs Quantum Dot Infrared Photodetectors
… research is to achieve a better understanding of dopant incorporation into the active region of QDIPs, which is directly related to dark current control and spectral response. From this dissertation research, doping related dipole fields are found to be responsible for excessive dark current in …
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Laser Annealing and Dopant Activation in III-V Materials
… by achieving high active concentrations of dopants in these materials. We have broadly characterized LSA for III-V and III-N materials with a high-throughput, combinatorial processing method. With this method, we explored kinetically limited states that are inaccessible using typical heating …
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Dopant effects on solid-solid transitions in atomic clusters
… melting temperature to the presence of a single dopant atom. This thesis theoretically examines the effect of a single dopant on the solid-solid transitions of LJ clusters characterised by a double-funnel energy landscape. The incorporation of a dopant atom into LJ38 or LJ31 offers a tunable …
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Determining rare earth dopant concentrations in optical fibres and waveguides
… is dependent on many parameters, including the dopant concentration. Accurate modelling of such devices require knowledge of the dopant concentrations and/or dopant distribution. Current techniques for determining dopant concentration are applicable to bulk samples and fibre preforms but can not …
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Progress towards quantitative dopant profiling with the scanning electron microscope
… obtain an accurate quantitative two-dimensional dopant profiling technique with high spatial resolution. Secondary electron (SE) imaging in the scanning electron microscope (SEM) has been shown to be a very promising technique for dopant profiling in the past. However, the limited accuracy …
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3d magnetic dopant atoms in transition-metal superconductors: Part I: Localized magnetic moments on chromium and manganese dopant atoms in niobium and vanadium; Part II: The effects of chromium and manganese dopant atoms on the upper critical magnetic field of niobium
… with the pair-breaking effects of Cr and Mn dopant atoms on the upper critical magnetic field of Nb. In Part I we review the experimental situation regarding the presence of localized magnetic moments on 3d dopant atoms in transition-metal superconductors, and briefly describe the salient …
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Multi-Dimensional Dopant Profiling With Atomic Resolution by Scanning Tunneling Microscopy
… surface opens the way to STM studies of dopant distributions in Si(100). STM topographic images, dI/dV images and current image tunneling spectroscopy (CITS) were acquired across the lateral PN junctions of Si devices. Two-dimensional dopant (carrier) profiles were extracted from CITS …
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Characterization of Dopant Diffusion in Bulk and lower dimensional Silicon Structures
… and drain regions and the redistribution of the dopants in the channel greatly impact the electrical characteristics of the fabricated device. Thus, in nano-scale and reduced dimension transistors, a tight control of doping levels and formation of pn junctions is required. Therefore, deeper …
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Three-Dimensional Magnetic Dopant Atoms in Transition-Metal Superconductors: Part I. Localized Magnetic Moments on Chromium and Manganese Dopant Atoms in Niobium and Vanadium. Part Ii. The Effects Ofchromium and Manganese Dopant Atoms on The Upper Critical Magnetic Field of Niobium (Squid)
… with the pair-breaking effects of Cr and Mn dopant atoms on the upper critical magnetic field of Nb.
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Materials properties of hafnium and zirconium silicates: Metal interdiffusion and dopant penetration studies.
… stability, electrical properties, and reduce dopant penetration. Because CMOS processing requires high temperature anneals (up to 1050 °C), it is important to understand the diffusion properties of any metal associated with the gate dielectric in silicon at these temperatures. In addition, …
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Boron and phosphorous implantation into (100) germanium : modeling and investigation of dopant annealing behavior
… critical properties like Pearson parameters and dopant activation temperatures are not well established. In this study, boron and phosphorus were implanted into (100) germanium with energies ranging from 20 to 320 keV and doses of 5 x 10^{13} to 5 x 10^{16} cm^{-2}. The behavior of the boron and …
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Bulk Growth of Semiconductor Crystals in a Magnetic Field: A Study of Dopant Transport
Our model for the unsteady transport of a dopant during the entire period of time required to grow a crystal assumes that the externally applied magnetic field is sufficiently strong that inertial effects and convective heat transfer are negligible. We divide the semiconductor melt into (1) …
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H-Mediated Film Growth and Dopant Incorporation Kinetics During Silicon Germanium(001):boron Gas-Source Molecular Beam Epitaxy
Based on all the above results, the growth kinetics of B doped Si 1-xGex(001) GS-MBE were modeled. Film deposition rates RSiGe decrease by ≈50% with increasing CB ≥ 5 x 1019 cm-3 at Ts = 500°C. The TPD results were used to determine the B segregation enthalpy, -0.4 eV, significantly lower …
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Thermal and low-energy ion doping of silicon(001) during molecular beam epitaxy: Dopant incorporation kinetics and mechanisms
… temperature T$\sb{\rm s}$ (500-1050$\sp\circ$C), dopant energy E$\sb{\rm d}$ (thermal-500 eV), and Si deposition rate R$\sb{\rm Si}$ (0.18-4.7 $\mu$m h$\sp{-1}).$ Surface segregation during thermal doping led to severe profile broadening and low temperature-dependent incorporation probabilities …
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Effects of Depth Variation of Substrate Dopant Impurity Concentration on the Interface Trap Density Determination in Mos Devices (Semiconductor)
The effect of dopant impurity concentration variation with depth on the interface trap density determination using the high-frequency capacitance-voltage (HFCV) or Terman method with a constant dopant concentration assumption has been quantitatively studied. A systematic correction scheme for …
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Thermodynamics and kinetics of hydrogen storage in magnesium hydride: a theoretical study of catalyst-dopant, defect, and size effects
… by ball-milling) and/or adding catalyst dopants? Thus, we need to determine accurately both the enthalpy and kinetic barriers controlling desorption, but for realistic, defected cases. Employing density functional theory (DFT) and simulated annealing, we studied initial H2 desorption from …
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High mobility germanium MOSFETs : study of ozone surface passivation and n-type Dopant channel implants combined with ALD dielectrics
Germanium offers higher electron and hole mobility than silicon, making it an attractive option for future high-performance MOSFET applications. To date, Ge p-channel device behavior has shown promise, with many reports of measured hole mobilities exceeding that of Si. However, Ge n-channel devices …
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