Amorphous and microcrystalline GeC:H films prepared by magnetron sputtering

Abstract

Hydrogenated germanium‐carbon alloy (GeC:H) films have been deposited by a reactive rf magnetron sputtering of Ge in methane–argon gas mixtures. As the second sputtering gas, helium is utilized in order to control the film properties. The effect of helium partial pressure ratio R to the total sputtering gas on the structural, optical and electrical properties of the films was investigated. The films show the amorphous nature in the low‐R range up to 60%. In the high‐R range above 60%, the bonding configuration in IR spectra changes, the diffraction lines of XRD appear, the optical bandgap decreases, and the dc conductivity increases clearly. It is found from these data that the microcrystallization of GeC:H films could be achieved by introducing helium during the sputtering process. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

Metastable Ge1–xCx Alloy Nanowires

“…The increase of Ge−C band intensity indicated that the concentration of the substitutional carbon could be controlled by CVD growth parameters. 54,55 The Ge (111) diffraction peak positions of Ge 1−x C x alloy NWs under different growth conditions were carefully evaluated in order to investigate structural change by carbon incorporation (Figure 4e, f). The lattice constant of the alloy NWs was calculated from the XRD pattern and Bragg equation (see Figure S2 in the Supporting Information).…”

“…Two strong absorption bands around 590 and 640 cm –1 were clearly visible, and were attributed to the Ge–H wagging and Ge–C vibrations, respectively. − As the growth temperature and partial pressure of carbon were increased, the intensity of the absorption band corresponding to the Ge–C stretching vibration was increased dramatically (Figure c, d). The increase of Ge–C band intensity indicated that the concentration of the substitutional carbon could be controlled by CVD growth parameters. , The Ge (111) diffraction peak positions of Ge 1– x C x alloy NWs under different growth conditions were carefully evaluated in order to investigate structural change by carbon incorporation (Figure e, f). The lattice constant of the alloy NWs was calculated from the XRD pattern and Bragg equation (see Figure S2 in the Supporting Information).…”

Non‐hydrogenated amorphous germanium carbide with adjustable microstructure and properties: a potential anti‐reflection and protective coating for infrared windows

“…Gazicki and Janowska reported that thin germanium/carbon alloy films prepared by radio frequency glow discharge using tetraethylgermanium . Since these early studies, Saito and Hu have produced films by reactive radio frequency magnetron sputtering of germanium in methane–argon gas mixtures. However, a great deal of hydrogen content from the precursors remained in the films.…”