Sökning: "GAAS"

Visar resultat 6 - 10 av 234 avhandlingar innehållade ordet GAAS.

  1. 6. Atom-Probe Field-Ion Microscopy of Electronic Materials

    Författare :Qiu-Hong Hu; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Au GaAs; ohmic contact; superconductors; oxygen ordering; AuGe GaAs; defects; Ag GaAs; Schottky contact; YBa2Cu3O6 delta; APFIM;

    Sammanfattning : This thesis presents work in which atom-probe field-ion microscopy (APFIM) has been applied to two types of electronic materials. In the case of metal/GaAs contacts, the purpose was to characterise the microstructure of the contact interface, particularly the chemical composition variation across the interface. LÄS MER

  3. 7. Atom Probe Field Ion Microscopy of Surface Zones, Coatings and Interfaces

    Författare :Anders Kvist; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Ag GaAs; ohmiccontact; Au GaAs; Schottky contact; Cu3Au; APFIM; AuGe GaAs; gradient sintering; cemented carbides; CVD;

    Sammanfattning : This thesis is focused on developingmethods for high resolution microanalysis of coatings on a substrate, andsurface zones of a bulk sample using atom probe field ion microscopy,APFIM. The APFIM technique is described and some examples of its applications to semiconductors,cemented carbides and intermetallic compounds are given. LÄS MER

  4. 8. 60 GHz Mixer and Multifunctional MMICs in GaAs pHEMT and mHEMT technologies

    Författare :Sten Gunnarsson; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Image reject mixer; Broadband wireless communication; Single-chip; Multifunctional; Mixer; Balanced resistive mixer; GaAs; Dual-quadrature mixer; 60 GHz; Receiver; pHEMT; MMIC; High data-rate; Double balanced Gilbert mixer; mHEMT; Transmitter; V-band;

    Sammanfattning : In recent years, the 60 GHz band has gained increased academic and commercial interest mainly due to the relative large amount of license free and little used frequency spectrum located in vicinity of 60 GHz. The exact locations of these free frequency bands varies locally but the 5962 GHz band overlap around the world and is therefore a true world wide license free band. LÄS MER

  5. 9. Threshold and Temperature Characteristics of InGa(N)As-GaAs Multiple Quantum Well Lasers

    Författare :Göran Adolfsson; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; GaAs; Semiconductor lasers; molecular beam epitaxy; multiple quantum wells; characteristic temperature; temperature dependence; dilute nitrides; ambipolar diffusion; InGa N As;

    Sammanfattning : Semiconductor lasers emitting in the 1.3 μm regime are of interest for applications in access-networks like fiber-to-the-home and radio-over-fiber systems. Suchfiber optical networks are expected to replace the copper-based access-networks currently in use due to a continuously increasing demand on user bandwidth. LÄS MER

  7. 10. Silicon δ-doping and Isoelectronic Doping in GaAs ans GaN Layers Grown by MBE

    Författare :Jan Thordson; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; MBE; doping; GaN; III-V; delta-doping; heterostructures; GaAs;

    Sammanfattning : This work concerns MBE-grown material, particularly physical effects due to controlled impurities of Si and N in arsenides, and the growth of nitrides and studies of Al- and As-impurities in them. Apart from interesting physical phenomena there are important device applications. The first part is devoted to studies of Si .delta. LÄS MER