Sökning: "surface passivation"

Visar resultat 1 - 5 av 65 avhandlingar innehållade orden surface passivation.

1. 1. Methods for Characterization and Optimization of AlGaN/GaN HEMT Surface Passivation

   Författare :Martin Fagerlind; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; surface states; surface passivation; annealing; processing; AlGaN GaN HEMT; MIS-capacitor;

   Sammanfattning : The Gallium Nitride based high electron mobility transistor is rapidly improving and is emerging as a viable alternative for use in high power applications operating in the microwave frequency domain. The suitability of the AlGaN/GaN material system is due to the possibility to grow epitaxial heterostructures that provide; high electron mobility, high electron saturation velocity, high carrier density and a high dielectric breakdown field. LÄS MER

3. 2. Passivation of Austenitic Stainless Steel

   Författare :Lena Wegrelius; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; stainless steel; chloride; molybdenum; passivation; hydrochloric acid; nitrogen; ESCA; dissolution;

   Sammanfattning : The objective of this thesis is to study the corrosion resistance and passivation of high alloyed austenitic stainless steels exposed to hydrochloric acid. The introductory section gives a background to the subject; electrochemical measurements and surface analysis by the ESCA-technique (Electron Spectroscopy for Chemical Analysis). LÄS MER

4. 3. Characterization and Analysis of Surface Passivations and Gate Insulators for AlGaN/GaN Microwave HFETs

   Författare :Martin Fagerlind; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; HFET; passivation characterization; passivation; AlGaN GaN heterostructure;

   Sammanfattning : The large bandgap of gallium nitride (GaN) and aluminum gallium nitride (AlGaN) offers an inherently high intrinsic breakdown field. When the materials are joined into the AlGaN/GaN heterostructure a 2-dimensional electron gas (2DEG) with a high electron density as well as high electron mobility is generated. LÄS MER

5. 4. Optimization of Ohmic Contacts and Surface Passivation for ‘Buffer-Free’ GaN HEMT Technologies

   Författare :Chen Ding Yuan; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; QuanFINE; passivation; GaN HEMT; pretreatment; ohmic contact;

   Sammanfattning : Gallium nitride high electron mobility transistors (GaN HEMTs) draw attention from high frequency and high power industries due to unique properties including high electron mobility and saturation velocity combined with high breakdown voltage. This makes GaN HEMTs suitable for power devices with high switching speed and high frequency applications with high power density requirements. LÄS MER

7. 5. Termination and passivation of Silicon Carbide Devices

   Författare :Maciej Wolborski; Anders Hallén; Jan Szmidt; KTH; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Silicon Carbide; SiC; passivation; dielectric materials; Semiconductor physics; Halvledarfysik;

   Sammanfattning : Silicon carbide rectifiers are commercially available since 2001, and MESFET switches are expected to enter the market within a year. Moreover, three inch SiC wafers can be purchased nowadays without critical defects for the device performance and four inch substrate wafers are announced for the year 2005. LÄS MER