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Magnetostriction temperature dependencies in Tb0.3Dy0.7 (Fe1−xMnx)2 were investigated. Mn substitution lowers the spin reorientation temperature, at which magnetostriction shows a sharp drop. Moreover, Mn containing compounds show larger magnetostriction than that for a Mn-free compound at low temperature. Mössbauer measurements show that easy magnetization direction for the Mn containing compound is in the 〈111〉 direction at 300 K, while it is in the 〈100〉 at 77 K. These results indicate that the tetragonal distortion λ100 increases by Mn addition in Tb0.3Dy0.7Fe2.

A dual-frequency superimposed (DFS) 100 MHz and 3.2 MHz rf capacitive-coupled plasma etch process for sub-90 nm devices has been developed. The electron density of DFS reactive ion etching (RIE) plasma at 40 mTorr was controlled from 4.0×1010 to 3.6×1011 cm-3 by adjusting the 100 MHz rf power, and the self-bias voltage (-V dc) was controlled from 20 to 760 V by adjusting the superimposed 3.2 MHz rf power. DFS RIE demonstrated independent control of electron density and self-bias voltage in a wide range. In the damascene etch process of SiOC film using Si3N4 as an etch mask, it was found that mask edge erosion is dependent on ion energy regardless of the selectivity of SiOC to Si3N4. DFS RIE offers the most suitable process for damascene etching of SiOC, which requires precise ion energy control.

This study investigates the mechanism of H2/N2 plasma ashing damage of porous SiOCH films. Porous SiOCH films were treated by a H2/N2 plasma using a 100-MHz capacitively coupled plasma etcher. The impact of ions, radicals, and vacuum ultraviolet radiation on the porous SiOCH films was investigated using in situ bulk analysis techniques such as spectroscopic ellipsometry and Fourier-transform infrared spectroscopy and ex situ film characterization techniques such as dynamic secondary ion mass spectrometry and x-ray photoelectron spectroscopy. In addition, plasma analysis including vacuum ultraviolet absorption spectroscopy was performed. The film characterization and plasma analysis show that the extraction of methyl by H radicals was enhanced by light while N radicals were responsible for inhibit the extraction of Si-CH3 bonds by forming nitride layer. The H2/N2 plasma damage mechanism is discussed based on characterization of the film and plasma diagnostics.

The modification of porous low-dielectric (low-k) SiOCH films by ashing plasma irradiation and subsequent exposure to air was investigated by in situ characterizations. Porous blanket SiOCH film surfaces were treated by a H2 or H2/N2 plasma in a 100-MHz capacitively coupled plasma reactor. The individual or combined effects of light, radicals, and ions generated by the plasmas on the chemical bonds in the porous SiOCH films were characterized using an in situ evaluation and by in situ Fourier-transform infrared reflection absorption spectroscopy (IR-RAS). In situ IR-RAS analysis revealed that the number of Si-OH, Si-H, and Si-NH2 bonds increased while the number of Si-CH3 bonds decreased during exposure to a H2 or H2/N2 plasma. Subsequent air exposure increased the number of Si-OH bonds by modifying Si-O-Si structures. The experimental results indicate that light emitted from a H2 or H2/N2 plasma can break Si-CH3 and Si-O-Si bonds and thereby generate dangling bonds. Radicals (e.g., NxHy and H radicals) can break Si-CH3 and Si-O-Si bonds and Si-NH2, Si–H, and Si-OH bonds could be formed. Si-NH2, Si-H, and dangling bonds react with moisture in the air cause the formation of Si-OH bonds. The dehydroxylation reaction on Si-OH was found to be the origin of Si-O-Si network structures. The mechanism of the degradation of porous low-k SiOCH films induced by a H2 or H2/N2 plasma is discussed based on the in situ characterization results.