Technique For Analysis Of Thin Films Research Articles

Determination of thickness and composition of high-k dielectrics using high-energy electrons

We demonstrate the application of high-energy elastic electron backscattering to the analysis of thin (2–20 nm) HfO2 overlayers on oxidized Si substrates. The film composition and thickness are determined directly from elastic scattering peaks characteristic of each element. The stoichiometry of the films is determined with an accuracy of 5%–10%. The experimental results are corroborated by medium energy ions scattering and Rutherford backscattering spectrometry measurements, and clearly demonstrate the applicability of the technique for thin-film analysis. Significantly, the presented technique opens new possibilities for nm depth profiling with high spatial resolution in scanning electron microscopes.

Study on chemical vapor deposited copper films on cyano and carboxylic self-assembled monolayer diffusion barriers

Thin copper films were produced by chemical vapor deposition using the precursor Cu IIbis-hexafluoroacetylacetonate on the SiO 2/Si substrate modified with cyano and carboxylic self-assembled monolayers (SAMs) as diffusion barriers. The characterizations of the deposited copper films were measured by various thin film analysis techniques, i.e., scanning electron microscopy, atomic force microscopy, X-ray photoelectron spectroscopy and X-ray diffraction. The comparison between copper deposited on SiO 2 and on the SAM-modified SiO 2 substrates indicates that the copper films tend to be deposited onto the SAM-modified substrate, which is further proved by the calculation results of the interaction energies of copper and the SAMs with density functional theory method.

Quantification of the incorporation coefficient of a reactive gas on a metallic film during magnetron sputtering: The method and results

Reactive Magnetron Sputtering is a complex process and huge efforts are made addressing the understanding of its fundamental phenomena and the simulation of the deposition process by e.g. Particle in Cell/Monte Carlo (PIC/MC). One of the most uncertain parameters in this reactive sputtering process is the incorporation coefficient of the reactive gas in the growing layer, i.e. the real-time sticking coefficient during deposition. In this work, mass spectrometry is used to deliver more insights on this complex matter.Earlier, a method was developed to determine the incorporation coefficient of the reactive gas molecules in the growing metal film, using mass spectrometry combined with thin film analysis techniques (electron probe microanalysis and x-ray photoelectron spectroscopy). This method delivers a global, realistic incorporation coefficient which can be used in models for the reactive sputtering process. In this work, new insights have been added to the classical method. As previously only molecular reactive gas particles were considered, the here described method extends to determine the global incorporation coefficient of all reactive gas particles, i.e. both molecular as atomic. The incorporation coefficient of oxygen gas during the reactive magnetron sputtering of Cu, Al, Mg and Y, is determined. It can be concluded that for the first three metal systems, the obtained incorporation coefficient is mainly determined by the molecular oxygen, while for Y both atomic and molecular oxygen are important. Furthermore, a trend between the difference in electronegativity of the metal and the reactive gas, and the incorporation coefficient can be observed.

The international VAMAS project on X-ray reflectivity measurements for evaluation of thin films and multilayers — Preliminary results from the second round-robin

X-ray reflectometry (XRR) is a unique technique for thin film analysis providing information on thickness, density, and roughness. The Versailles Project on Advanced Materials and Standards (VAMAS) project “X-ray reflectivity measurements for evaluation of thin films and multilayers” has the goal to assess the accuracy and precision of thickness, density and roughness as determined by XRR measurements and simulations. Here we present preliminary results from the second round-robin analysis on a TaN/Ta metallization on a silicon substrate. This work demonstrated a good inter-laboratory reproducibility for the tantalum film thickness with a standard deviation of 0.04 nm corresponding to about 0.3%. The use of the auto-correlation function (extracted from the derivative of density profiles obtained via a Fourier transform) was found to provide useful layer thickness measurements from important samples that are too complex for a simple direct simulation and fitting approach.

Low-temperature magnetron sputter-deposition, hardness, and electrical resistivity of amorphous and crystalline alumina thin films

Aluminum oxide films were grown by reactive magnetron sputtering. In order to maintain a stable deposition process and high deposition rate, a pulsed direct current bias was applied to the aluminum target and the substrate. An external solenoid was used to form a magnetic trap between the target and the substrate. The influence of substrate temperature, substrate bias, and the magnetic trap on film growth and properties was studied by different surface and thin-film analysis techniques and electrical measurements. Normally, amorphous alumina films were produced. However, under optimum process conditions, crystalline alumina films can be obtained at temperatures as low as 250 °C, with a hardness ∼20 GPa and excellent electrical insulating properties.

Elastic recoil detection (ERD) with extremely heavy ions

Extremely heavy-ion beams such as 209Bi in elastic recoil detection (ERD) make ERD a uniquely valuable technique for thin-film analysis of elements with mass ≤ 100. We report ERD measurements of compositional analysis of dinosaur eggshells and bones. We also show the capability of the ERD technique on studies of thin-film, high-temperature superconductors.

Contribution to the characterization of reference materials for thin-film analysis in solar-energy and semiconductor technologies

A combined approach of independent surface and bulk analytical methods was applied to characterize materials that had been prepared by ion implantation of P. Co and Ni ions into high purity silicon, for use as reference materials in thin-film analysis techniques. In this characterization, high precision and accuracy of 1–2% were obtained by utilizing instrumental neutron activation analysis for the determination of the total implanted ion dose. The impact of the analytical results on the preparation procedure is discussed.

Use of surface and thin film analysis techniques to study metal-organic and metal-polymer interaction: A review

Very thin organic or polymer films can be analyzed using several analytic techniques. The thickness of the films discussed ranges from monolayers to several thousand ångströms. The techniques described are X-ray photoelectron spectroscopy, IR spectroscopy, ellipsometry and use of the quartz crystal oscillator microbalance. The last technique was applied to a fluoropolymer deposited onto a silver surface. The parameters which control film thickness and unformity are discussed along with how these parameters are measured. The second example discussed is the application of nitrogen-containing organic molecules to copper and iron surfaces. The chemical bonding is discussed along with the orientation of the molecules in the resulting film and the analytical techniques used.