Bonding properties of rf-co-sputtering amorphous Ge–C films studied by X-ray photoelectron and Raman spectroscopies

Amorphous nonstoichiometric Ge1−x–Cx:H compounds obtained by radiolysis-chemical vapor deposition of germane/ethyne or germane/allene systems: A bonding and microstructure investigation performed by x-ray photoelectron spectroscopy and Raman spectroscopy

“…Our data seem at least partially consistent with the results obtained by Marques and co-workers: 44,45 in fact, the C1s spectra recorded clearly evidence the formation of carbidelike species ͑peak C1 at 283.3 eV͒, at about the same BE reported by the authors. Moreover, the increase in the C molar fraction influences the C1/C2 ratio, and the relative intensity of peak C2 increases.…”

“…Marques and co-workers, for instance, studied the formation of Ge x C 1−x : H alloys prepared by rf sputtering. 44,45 The authors have observed the presence of a single peak in the Ge3d spectra, found at a binding energy included between 29.5 and 31.0 eV, the BE value growing with the carbon content in the sample ͑i.e., decreasing with x͒. An equivalent effect was evidenced in the correspondent C1s spectra, showing the presence of a low BE peak ͑283.4 eV͒ attributed by the authors to carbidelike species and a graphite peak at 284.5 eV.…”

Chemical bonding and optical properties of germanium–carbon alloy films prepared by magnetron co-sputtering as a function of substrate temperature

“…7. One component, at about 283.7 eV, is ascribed to Ge\C bonds in carbide forms, the other component, at about 284.5 eV, is ascribed to C\C bonds [14]. The solid lines are the fitted data, and the dots are experimental points.…”

“…5, the dash line is a reference line. It has been found that the formation of C\Ge bond in the a-Ge 1 − x C x films can cause a upshift of Ge 3d binding energy [14]. The Ge 3d spectra for a-Ge 1 − x C x films which are the shifting and broadening for Ge 3d peak induced by carbon incorporation can be clearly observed.…”

Conventional pyrolysis of [CCSiMe2CCGeMe2]n polymer precursor for Si/Ge/C materials

“…Moreover, solubility of carbon in silicon is very low (10 17 cm À3 at the melting point) and in germanium extremely low (10 8 cm À3 ). For example, Vilcarromero et al [23] found that during rf-co-evaporation of Ge and C targets for production of Ge 1Àx C x films germanium atoms were dispersed in sp 3 hybridized carbon and over x > 0.2 sp 2 carbon domains were formed; López et al [24] observed in thin SiGeC films produced by ArF laser CVD of disilane, germane and ethene an independent incorporation of Ge and C atoms; Hu et al [22] produced Ge 1Àx C x films by rf sputtering in which germanium and carbon clusters were built in a composite amorphous material; Kazimierski et al [25] fabricated by plasma CVD in an audio frequency three electrode reactor insulating and semiconducting a-Ge x C y :H thin films using (CH 3 ) 4 Ge. The films possessed a composite structure of germanium cluster, chains and nanocrystals embedded in sp 3 /sp 2 carbon surroundings.…”