Feinfokussierte Ionenstrahlen dienen in den Gebieten der Halbleiterindustrie und Materialforschung der Mikro- und Nanostrukturierung. Die vorliegende Arbeit beschäftigt sich mit den beiden Hauptanwendungen von fokussierten Ionenstrahlen, dem Materialabtrag und der ionenstrahlinduzierten Materialabscheidung. Dabei wird die hochauflösende Ionensäule CANION 31Z der Firma Orsay Physics mit Stromdichten von bis zu 10 A/cm2 und mit integriertem Gassystem eingesetzt. Es wird ausführlich auf Anwendungsbeispiele von Fokussierten Ionenstrahlsystemen im Bereich der Industrie und Forschung eingegangen. Schwerpunktmäßig wird die Abscheidung von Wolfram aus dem Precursorgas W(CO)6 (Wolframhexacarbonyl) auf Si und SiO2 als Substrat untersucht, mit dem Ziel, gut leitfähige Drähte (hier im Sinne von Leiterbahnen) mit minimalem Querschnitt herzustellen. Die Optimierung der Ionenstrahl-Parameter dieser Feinfokussierten Ionenstrahlanlage bezüglich der Abscheidung steht im Vordergrund. Dabei wird ein kurzer Einblick in die Theorie der Schichtentstehung beim Abscheidevorgang gegeben. Untersuchungen der erzeugten Strukturen entsprechend der Schichtqualität und der Strukturabmessungen werden erläutert und die Ergebnisse diskutiert. Es konnten Wolframdrähte mit einer Länge von 20 ... 100 µm, einer Breite von minimal 150 nm und einer Höhe von maximal 600 nm angefertigt werden. Die Zusammensetzung der Drähte in Abhängigkeit der Prozessparameter wurde mittels AES bestimmt. Im optimalen Fall wurden die Schichtanteile zu 80% W, 5% O, 6% C und 9% Ga ermittelt (Angaben in Atomprozent). Der spezifische Widerstand der Wolframdrähte ist im Bereich 150 ... 320 µWcm gemessen worden.

Pulse Pressure Metal-Organic Chemical Vapour Deposition (PP-MOCVD) is a technique for creating thin coatings. It is less dependent on the volatility of precursors than other Chemical Vapour Deposition (CVD) processes as the precursors are introduced into the reaction chamber as an aerosol; therefore sublimation of the precursor is not necessary. This allows solutions of multiple compounds to be created with a known concentration and ratio of precursors. We explored the formation of hydroxyapatite (HAp) coatings for use on bone implants, using a methanolic solution of calcium lactate and trimethyl phosphate (TMP) as a PP-MOCVD precursor solution. The thermal decomposition of the precursors and the reaction between them were investigated using Thermogravimetric Analysis (TGA). Several variables on the PP-MOCVD apparatus were varied to test their effect on the formed coating: deposition temperatures, ratio of precursors, number of pulses, precursor concentration, the use of ambient temperatures and annealing the coatings after formation. All the coatings were analysed using Scanning Electron Microscope (SEM), Energy Dispersive Spectroscopy (EDS) and Fourier Transform Infra-Red spectroscopy (FTIR). These coatings were not uniformly smooth in appearance at the micro level. However, using higher deposition temperatures, an excess ratio of TMP to calcium lactate and annealing the coatings for short periods of time and low temperatures improved the uniformity of the coating. When vigorous annealing was performed it resulted in surface oxidation and the production of titanium dioxide (TiO2 ). The EDS results showed that both calcium and phosphorus were present in the coatings. The use of high deposition temperatures, excess TMP or gentle annealing resulted in calcium to phosphorous ratios similar to the stoichiometry of HAp. These same conditions gave improved coating uniformity.

Pulse Pressure Metal-Organic Chemical Vapour Deposition (PP-MOCVD) is a technique for creating thin coatings. It is less dependent on the volatility of precursors than other Chemical Vapour Deposition (CVD) processes as the precursors are introduced into the reaction chamber as an aerosol; therefore sublimation of the precursor is not necessary. This allows solutions of multiple compounds to be created with a known concentration and ratio of precursors. We explored the formation of hydroxyapatite (HAp) coatings for use on bone implants, using a methanolic solution of calcium lactate and trimethyl phosphate (TMP) as a PP-MOCVD precursor solution. The thermal decomposition of the precursors and the reaction between them were investigated using Thermogravimetric Analysis (TGA). Several variables on the PP-MOCVD apparatus were varied to test their effect on the formed coating: deposition temperatures, ratio of precursors, number of pulses, precursor concentration, the use of ambient temperatures and annealing the coatings after formation. All the coatings were analysed using Scanning Electron Microscope (SEM), Energy Dispersive Spectroscopy (EDS) and Fourier Transform Infra-Red spectroscopy (FTIR). These coatings were not uniformly smooth in appearance at the micro level. However, using higher deposition temperatures, an excess ratio of TMP to calcium lactate and annealing the coatings for short periods of time and low temperatures improved the uniformity of the coating. When vigorous annealing was performed it resulted in surface oxidation and the production of titanium dioxide (TiO2 ). The EDS results showed that both calcium and phosphorus were present in the coatings. The use of high deposition temperatures, excess TMP or gentle annealing resulted in calcium to phosphorous ratios similar to the stoichiometry of HAp. These same conditions gave improved coating uniformity.

Zugl.: Karlsruhe, Univ., Diss., 2006

Universiẗat, Diss., 2006--Kassel.

Universiẗat, Diss., 2006--Karlsruhe.

Techn. University, Diss., 2000--Berlin.

Brandenburgische Techn. Universiẗat, Diss., 2004--Cottbus.

Techn. Universiẗat, Diss., 2000--Berlin.

Techn. Universiẗat, Diss., 2002--Berlin.