Characterization of the effect of growth conditions on a-SiC:H films

Abstract

The effects of dissipated power and gas dwell time in SiH4+CH4 plasmas on the properties of a-SiC:H films deposited by plasma-enhanced chemical-vapor deposition have been investigated for different methane fractions in plasmas operating in the low-power regime. Optical, structural, and electrical characterizations have been performed in order to investigate the influence of dissipated power and molecule dwell time on the physical properties of a-SiC:H films. It was found that both the investigated deposition parameters can have a remarkable influence on carbon incorporation and on optical properties such as the energy gap. In particular an increase in the dissipated power or in the molecule dwell time leads to an increase in carbon incorporation and in energy gap. The electrical properties and defect density are still those of device quality films grown in standard deposition conditions and are not influenced by variations in dissipated power or gas dwell time. From these results some conclusions regarding the growth mechanisms are drawn.

Structural, optical and electrical properties of helium diluted a-Si1−xCx:H films deposited by PECVD

“…For all the samples the deposition conditions have been chosen so as to optimize their properties as reported elsewhere [2]. The CH 4 percentage in the SiH 4 -CH 4 plasma was varied between 0% and 80%.…”

Effect of RF power and gas flow ratio on the growth and morphology of the PECVD SiC thin film s for MEMS applications

“…Therefore, higher incorporation of CH 4 lowers the concentration of SiH 4 and SiH n radicals which decreases the Si-C bond due to less availability of silicon. 25,26 Hence, surface roughness can be controlled by varying the deposition parameters such as RF power, mixed frequency and flow ratio. Such deposition parameters can also effect the growth morphology and microstructure of the SiC thin films.…”

Optoelectronic properties of a‐Si1–xCx:H films grown in hydrogen diluted silane‐methane plasma

“…In this mode of preparation, the carbon is incorporated mainly in the form of methyl groups (-CH 3 ), thus preserving the sp 3 hybridization in the solid. The properties of a "chemically ordered" alloy depend only weakly on the deposition parameters other than the composition of gas mixture [9]. In the high-power regime, both SiH 4 and CH 4 are subject to primary decomposition thus enhancing the carbon incorporation efficiency.…”