Chemical (dis)order in a-Si1−xC

Abstract

We studied the local bonding structure of the hydrogenated amorphous silicon-carbon alloy system ͑a-Si 1Ϫx C x :H͒. The chemistry of the carbon incorporation in the alloys for 0ϽxϽ0.6 was analyzed by infrared and visible spectroscopies. The material was deposited in a controlled atmosphere of argon and hydrogen by rf cosputtering of Si and C targets. We found that up to xϷ0.2 the carbon atom prefers to bond in a chemically disordered configuration, i.e., homonuclear bonds are favored. Between 0.2ϽxϽ0.6 a tendency to chemical ordering is apparent. These results are consistent with the behavior of the optical gap, the Urbach energy, and the density of defects of the material as a function of x. ͓S0163-1829͑97͒11807-0͔

Hydrogenated nanocrystalline silicon carbide: fabrication, properties and heterostructure device application

“…1 shows the of IR spectra recorded in the region between 500 and 1200 cm -1 for the films obtained at the indicated T s values. The IR spectra show a predominant band peaking at around 790-800 cm -1 , which corresponds to the stretching mode vibrations of the Si-C bond [9]. This peak is shouldered by two structures located at about 900 and at 1000 cm -1 and which can be assigned to Si-H 2 bending and to C-H wagging or rocking modes [9], respectively.…”

“…The IR spectra show a predominant band peaking at around 790-800 cm -1 , which corresponds to the stretching mode vibrations of the Si-C bond [9]. This peak is shouldered by two structures located at about 900 and at 1000 cm -1 and which can be assigned to Si-H 2 bending and to C-H wagging or rocking modes [9], respectively. The presence of these bonded hydrogen is confirmed by the detection of their stretching counterparts at 2100 cm -1 and 2 900 cm -1 , respectively, as show in the inset of Fig.…”

Effect of hot-wire passivation on the properties of hydrogenated microcrystalline silicon films to reduce post-deposition oxidation

“…For as-treated films, IR spectra in the wavenumber region between 400 and 1400 cm À1 were composed of four fundamental peaks: Si-H wagging (630 cm À1 ) [14,15], Si-C stretching (780 cm À1 ) [14,15], Si-O stretching ($1050 cm À1 ) [16] or Si-CH n wagging ($980 cm À1 ) [14,15], and Si-CH 3 bending (1240 cm À1 ) [14,15] modes ( Fig. 1).…”

Si and SiC nanocrystals in an amorphous SiC matrix: Formation and electrical properties

“…Figure 4 shows FTIR spectra of samples from the same deposition but annealed at 900 °C. Additionally to the peaks in not annealed samples we found a Si-O x stretching peak at ~1080 cm -1 [12]. The Si-C absorption peak of the annealed samples was fitted with a pseudo-Voigt line profile.…”

“…In order to determine the initial density and structure of atomic bonds the not annealed samples of experiment A were investigated (see Table 1). FTIR spectra of not annealed SiC films show four peaks in the range from 400 cm -1 to 1300 cm -1 : Si-H n -wagging bond with n=1,2,3 at ~640 cm -1 [13], Si-C stretching bond at ~780 cm -1 [12], SiH 2 bending at ~900 cm -1 [12] and C-H wagging at ~1000 cm -1 [12] The peaks of not annealed samples were fitted with a Gaussian profile. …”