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 42 for “"Ohmic Contacts"”.
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Nano-scale ohmic contacts for III-V MOSFETs
… it is necessary to fabricate source and drain ohmic contacts with ultra-low contact resistance, perhaps as low as 50 [Omega] · [mu]m. This is particularly difficult to achieve as the device size shrinks down to the 10-20 nm length range since the contact resistance increases drastically for …
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Ohmic Contacts to N -Type Gallium Nitride Based Semiconductors
… of electrical and materials performance of ohmic contacts are presented. Surface treatment techniques were developed to improve the electrical characteristics of ohmic contacts. Ti/Al/Mo/Au metallization scheme was developed to form ohmic contacts to n-GaN, n-AlxGa1-xN, and AlGaN/GaN HEMTs. …
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Analysis of Mo sidewall ohmic contacts to InGaAs fins
… a vertical nanowire field-effect-transistor, the Ohmic contact at the top of the nanowire not only covers the top surface, but also wraps around the sidewall. Because the sidewall is considered to be different from the top surface, it is necessary to study the sidewall Ohmic contact properties …
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Modeling and Electrical Characterization of Ohmic Contacts on n-type GaN
… operation and efficient performance. The metal contacts on semiconductors are essential as the interface properties affect the semiconductor performance and device operation. The low resistance ohmic contacts for n-GaN have been well established while most p-GaN devices have still high contact …
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Investigation of Ohmic Contacts for Gallium Nitride-Based Power Electronic Devices Using Molecular Beam Epitaxy
… and develop stable and reproducible low ohmic contacts through careful monitoring of the GaN surface and distribution of dopants while employing SAG by plasma assisted molecular beam epitaxy (PAMBE). The work specifically involved thin film growth, film characterization, device …
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Monolithic Integration of Thermally Stable Enhancement-Mode and Depletion-Mode Indium Phosphide HEMTs Utilizing Iridium-Gate and Silver-Ohmic Contact Techniques
Excellent ohmic contacts based on Ge/Ag/Ni metallization have been developed for InAlAs/InGaAs/InP high electron mobility transistors (HEMTs) in a temperature range between 385 and 500°C for the first time. A minimum contact resistance of 0.06 O-mm was obtained at an annealing temperature of …
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Foundations of Ohmic Contact Formation on Aluminum Gallium Nitride/gallium Nitride Heterostructures
… and mm power amplifications. Fabrication of Ohmic contacts for such devices that meet the stringent low-resistance, high thermal stability and smooth surface morphology requirements has been challenging. In the cases where Ohmic behavior can be achieved, a full scientific understanding of the …
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Process Development and Characterization of AlGaN/GaN Heterostructure Field-Effect Transistors
… isolation etching, low-resistance drain/source ohmic contacts, and Schottky gate formation. These efforts along with related processing issues will be discussed. Devices were then fabricated on epitaxial layers grown on sapphire substrates and on n-type, p-type, and insulating SiC. While …
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Electronic properties of Bi nanowaves
… from the alumina template. High resistance non-ohmic contacts are attributed to a thick oxide layer formed on the surface of the nanowires. The non-linear 2-point i(V) response of these contacts is understood on the basis of a tunneling model. Techniques are developed for making ohmic contacts …
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TRANSPARENT ELECTRODE AND NOVEL BUFFER LAYER MATERIALS FOR ORGANIC PHOTOVOLTAICS
… transporting layers, which can establish ohmic contacts between the active layer and the two electrodes are essential parts. In this thesis, the study on transparent conductive polymeric electrode, which can replace normally used electrode indium tin oxide (ITO) was carried out. The ITO …
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Electrical and optical characterisation of bulk heterojunction polymer-fullerene solar cells
… emission theories. In case of ohmic contacts, the current conduction was found to be limited by the low mobilty of P3HT. Trap density was estimated from a space charge limited current model with traps distributed exponentially within the band gap. The efficiency of P3HT:PCBM …
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Development of Gallium Nitride-Based Power Electronic Devices Using Plasma-Assisted Molecular Beam Epitaxy
… conditions, and characterization skills of the ohmic and Schottky metal contacts are discussed. The present work especially focuses on the reduction of power losses in GaN-based FET devices. For the first time, the PAMBE-based selective-area growth (SAG) technique is demonstrated to improve the …
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Modulation-Doped Field-Effect Transistors for High-Power Microwave Applications
… thermal conductivity. Forming low-resistance ohmic contacts to modulation-doped InP channel heterostructures is a challenging issue and is investigated through the study of ion-implanted alloyed contacts and through cap layer design for nonalloyed contacts.
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Self-aligned AlGaN/GaN transistors for sub-mm wave applications
… high temperature anneal necessary for forming ohmic contacts were demonstrated. Devices with three different gate stacks, composed of tungsten and a high-k dielectrics like HfO₂, A1₂O₃ and HfO₂/Ga₂O₃, were studied and compared with respect to DC transistor measurements, capacitor measurements …
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Post assembly process development for Monolithic OptoPill integration on silicon CMOS
… the formation of alloyed and non-alloyed ohmic contacts on n-type and p-type InGaAs contact layers, active area definition by dry-etching InGaAs/InP with ECR-enhanced RIE, BCB passivation and planarization, via opening by dry-etching BCB with RIE, and top contact metallization. In …
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Modeling of Joule heating and thermoelectric transport in thin film silicon for SJEM measurement
… levels of 1019 cm-3 and 1018 cm-3. PtSi or NiSi Ohmic contacts are formed on the devices and thermoelectric behaviors are analyzed in conditions either under simultaneous DC and AC excitations, or AC only excitations. The simulation results show that thermoelectric contribution in heating …
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An exploration of chemical agents detection using the quantum fingerprint [superscript TM] technology
… appropriate semiconductor substrates and metal contacts for ohmic contacts, fabrication protocols and metallic pattern designs for optimal signals, development of sensor technology measurement protocols, and testing of sensor chips under a controlled environment. The substrate materials tested …
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Electrodeposited Ni/Ge and germanide schottky barriers for nanoelectronics applications
… the intrinsic surface states will help to create ohmic contacts for doped n-MOSFETs. NiGe were formed single phase by annealing. Results reveal that by using these high-quality germanide Schottky barriers as the source/drain, the subthreshold leakage currents of a Schottky barrier MOSFET could be …
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Silicon nanowire anode for lithium-ion batteries: fabrication, characterization and solid electrolyte interphase
… etching, and conductive nickel monosilicides ohmic contacts were created via simple one-step thermal annealing procedure between nanowires and nickel electrodes for integration. Composite anodes were prepared from electrolessly fabricated silicon nanowires for lithium-ion batteries, and an …
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Performance enhancement of GaN-based high-power hemts by selective-area growth using plasma-assisted molecular beam epitaxy
… a popular technique for improving Ohmic contacts. A consistent improvement in device performance by SAG was achieved, including lower contact resistance, higher peak drain currents and higher breakdown voltages. Since the results indicated that SAG is effective in fabricating HEMTs …
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