Amorphous Al2O3 Thin Films Research Articles

Nanoindentation of amorphous aluminum oxide films I. The influence of the substrate on the plastic properties

Using nanoindentation techniques, the mechanical properties of amorphous Al2O3 thin films with oxide thicknesses ranging from approximately 3 nm (native oxides) to 360 nm on substrates of polycrystalline Al and single crystals of sapphire and silicon have been investigated. The measured composite hardness as a function of the ratio of the indentation depth and the film thickness was compared with predictions of existing phenomenological models based on laws of mixture of the area or volume fractions. When the parameters are adjusted, these models can predict the measured hardness vs. indentation depth either for a hard film on a soft substrate or a soft film on a hard substrate. None of the models describes both cases. A new model based on a law of volume fractions is presented which, with relevant physical parameters, describes both cases, except for the thinnest films on soft substrates, where the discrepancy is assumed to be connected with a membrane-like deformation of the film.

Fabrication of aluminum oxide thin films by a low-pressure metalorganic chemical vapor deposition technique

Amorphous Al2O3 thin films were grown on Si(100) and glass substrates by low-pressure metalorganic chemical vapor deposition using aluminum acetylacetonate and water vapor as source materials. Water vapor played an important role in the oxidation process and produced carbon-free, pure Al2O3 films. The deposition temperature could be lowered to 230 °C. The films were characterized by means of x-ray diffraction, x-ray photoelectron spectroscopy, Auger electron spectroscopy, Rutherford backscattering spectrometry, and ellipsometry.

A self-focused multichannel electron beam source for annealing of ion-implanted semiconductors : Juh-Tzeng Lue, Sheau-Yang Shyu and Ling-Hsiao Lyu. Vacuum36(5), 275 (1986)

Chemical solution deposition of smooth amorphous Al2O3 thin films has been successfully used for planarization of long-length metallic substrates for 2G HTS superconducting wires production. A series of metal-organic precursors based on Al(iPrO)3, Al(acac)3, acetic acid, monoethanolamine (MEA) and diethylenetriamine (DETA) was developed. Correlations between the precursor composition and the features of its two-step thermal-induced transformation to amorphous Al2O3 were studied by 1H NMR, IR spectroscopy and thermal analysis. Utilizing the solutions of {Al(iPrO)3 + 2.5MEA + 6HAcet} in iPrOH and {Al(acac)3 + nDETA} in HAcet (n = 1 − 3) as precursors for dip-coating, we obtained the long-length Hastelloy C276 substrate covered by uniform amorphous 50–550 nm thick alumina films with surface roughness of about 0.5–1.5 nm. A 20 m long sample of 2G HTS wire with a commercial level of superconducting critical current of up to 300 A was prepared based on Hastelloy substrate tape planarized with Al2O3.

A modified ion source for semiconductor implantation purposes : A. Latuszynski, D. Maczka and Yu. V. Yushkievich and K. Kiszczak. Vacuum36(5), 263 (1986)

Chemical solution deposition of smooth amorphous Al2O3 thin films has been successfully used for planarization of long-length metallic substrates for 2G HTS superconducting wires production. A series of metal-organic precursors based on Al(iPrO)3, Al(acac)3, acetic acid, monoethanolamine (MEA) and diethylenetriamine (DETA) was developed. Correlations between the precursor composition and the features of its two-step thermal-induced transformation to amorphous Al2O3 were studied by 1H NMR, IR spectroscopy and thermal analysis. Utilizing the solutions of {Al(iPrO)3 + 2.5MEA + 6HAcet} in iPrOH and {Al(acac)3 + nDETA} in HAcet (n = 1 − 3) as precursors for dip-coating, we obtained the long-length Hastelloy C276 substrate covered by uniform amorphous 50–550 nm thick alumina films with surface roughness of about 0.5–1.5 nm. A 20 m long sample of 2G HTS wire with a commercial level of superconducting critical current of up to 300 A was prepared based on Hastelloy substrate tape planarized with Al2O3.

Detection of Single Ions by Fulse Counting: Application to Ion Microprobe Mass Analyzer

The need to detect low intensity beams of resolved ions with keV energy is encountered frequently in mass spectrometry. It is most readily accomplished by using some form of pulse-counting detector in which ions are allowed to strike a target surface (conversion dynode) where each ion releases a pulse of low energy secondary electrons. The secondary electrons undergo further amplification in an electron multiplier or scintillator type of ion detector which is specially designed to detect single ions. Ion-to-electron conversion, amplification of the secondary electrons, efficiency of ion detection by pulse counting and dead-time corrections to observed random counting rates are all statistical processes which must be understood so that observed data can be corrected properly to obtain precise and accurate measurements. These processes are reviewed, along with some of the basic properties of ion-induced secondary electron emission from an amorphous Al2O3thin film target. Ion detection in the ion microprobe is interpreted in light of these basic considerations, and several mass spectra are given for electron multiplier dynode surfaces.