AgCuAl and AgMgAl crystalline and amorphous metallic thin films for high optical reflection and low electric resistivity applications

Autor: Yen-ta Lin, 林彥達
Rok vydání: 2014
Druh dokumentu: 學位論文 ; thesis
Popis: 102
This study is separated into two parts: high reflection and low resistivity. The first part is focused on the low resistivity. The AgMgAl thin films in the form of metallic glasses or nanocrystaline phases are prepared by co-sputtering. The surface morphology, roughness, amorphous or crystalline atomic structure, grain size, and electric resistivity are systematically examined. The films are all about 1000 nm in thickness. Depending on the film compositions, the films can be fully amorphous or nanocrystalline, or a mixture of nanocrystalline phases in the amorphous matrix. For the fully amorphous films, the electric resistivity typically falls in the range from 750 to 1200 nm. In comparison, the nanocrystalline films possess the electric resistivity in the range from 150 to 500 nm. Thermal annealing at temperatures slightly below or above the glass transition temperature has been conducted to lower the sputtering defects and to relax the atomic structure. The thin films with initial amorphous structure and then crystallized during annealing are found to exhibit the lowest resistivity. For the second part, the metallic glass shows the smooth curve of reflectivity in the visible region. This character is better than that of the crystalline alloys; the latter would exhibit high reflection in infrared region but a drop in invisible and UV region. Compared to the sputtered films, the quality of thin films deposited by evaporation is better and the reflectivity is higher. This study uses the e-beam assisted evaporation to fabricate the AgCuAl films. The surface morphology, roughness, amorphous or crystalline atomic structure, reflectivity, and electric resistivity are systematically examined.
Databáze: Networked Digital Library of Theses & Dissertations
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