Ortsaufgelöste Charakterisierung von Entmischungsphänomenen in GaxIn1-xAsyP1-y-Heteroschichten im Raster-Transmissionselektronenmikroskop

Dateibereich 5231

14,74 MB in 14 Dateien, zuletzt geändert am 13.04.2007

Dateiliste / Details

DateiDateien geändert amGröße
Kapitel00.pdf07.12.2001 00:00:00109,9 KB
Kapitel01.pdf07.12.2001 00:00:0051,8 KB
Kapitel02.pdf07.12.2001 00:00:001001,4 KB
Kapitel03.pdf07.12.2001 00:00:0075,2 KB
Kapitel04.pdf07.12.2001 00:00:003,59 MB
Kapitel05.pdf07.12.2001 00:00:002,55 MB
Kapitel06.pdf07.12.2001 00:00:0047,9 KB
Kapitel07.pdf07.12.2001 00:00:0044,6 KB
Kapitel08.pdf07.12.2001 00:00:0054,1 KB
Kapitel09.pdf07.12.2001 00:00:0080,3 KB
Kapitel10.pdf07.12.2001 00:00:0045,7 KB
index.html13.04.2007 17:12:1916,5 KB
inhalt.htm13.04.2007 17:36:197,2 KB
mendorfdiss.pdf07.12.2001 00:00:007,10 MB
The use of the quaternary semiconductor alloy GaxIn1-xAsyP1-y for the development of new electronic, optoelectronic or high speed microwave devices is of great technological interest e.g. in telecommunication. Under certain manufacturing conditions unwanted variations in the chemical composition of these materials can occur, which can be attributed to the existence of a miscibility gap. These decomposition phenomena occur within the nanometer and subnanometer scale. Therefore it is necessary to use characterisation methods of high sensitivity and at the same time highest spatial resolution to investigate independently key parameters such as layer thickness, chemical composition or crystalline structure. The Scanning Transmission Electron Microscope (STEM) is suited for such material analyses since it combines illustrating and analytic characterisation methods together with high spatial resolution. The goal of this work was a comprehensive qualitative and quantitativ e investigation of decomposition in GaxIn1-xAsyP1-y using characterisation techniques like bright-field and Z-contrast imaging as well as electron energy loss spectroscopy (EELS) and convergent beam electron diffraction (CBED), performed in a STEM. For the first time the chemical decomposition process were quantified on the nanometer scale. The course of the decomposition and the predicted expansion of the miscibility gap could be acknowledged in the experiment. Additionally it was shown that by optimising growth parameters (e.g. pressure) of strain compensated superlattices the decomposition process could be inhibited or even stopped. At the same time for the improvement of the evaluation of high resolution Z-contrast images the maximum entropy method (MEM) was applied. Due to the use of the MEM the high resolution Z-contrast images permits the investigation of defect structures and for the first time using a STEM at 100 keV the dumb bells of GaSb was resolved in maximum entropy reconstruction
Keine URN zugeordnet
PURL / DOI:
Lesezeichen:
Permalink | Teilen/Speichern
Dokumententyp:
Wissenschaftliche Abschlussarbeiten » Dissertation
Fakultät / Institut:
Fakultät für Ingenieurwissenschaften » Elektrotechnik und Informationstechnik
Dewey Dezimal-Klassifikation:
600 Technik, Medizin, angewandte Wissenschaften » 620 Ingenieurwissenschaften
Stichwörter:
miscibility gap, Z-contrast, electron energy loss spectroscopy (EELS), hetero structure, maximum entropy method (MEM), superlattice, decomposition, Scanning Transmission Electron Microscope (STEM), convergent beam electron diffraction (CBED)
Beitragende:
Prof. Dr.-Ing Kubalek, Erich [Betreuer(in), Doktorvater]
Prof. Dr. rer. nat. Heime, Klaus [Gutachter(in), Rezensent(in)]
Sprache:
Deutsch
Kollektion / Status:
Dissertationen / Dokument veröffentlicht
Datum der Promotion:
07.12.2001
Dokument erstellt am:
07.12.2001
Dateien geändert am:
13.04.2007
Medientyp:
Text