Influence of substrate temperature on growth of a-Si:H films by reactive facing target sputtering deposition

Abstract

Hydrogenated amorphous silicon (a-Si:H) films were deposited by reactive facing target sputtering (FTS) technique with a mixture of Ar and H 2 reaction gas. Fourier transform infrared (FTIR) absorption, Raman scattering and ultraviolet-visible optical absorption are used to investigate the microstructure and optical properties of the deposited films. The decrease of the concentration of bonded hydrogen, especially that of (Si-H 2 ) n with increasing substrate temperature (Ts), was observed in FTIR spectra, suggesting the atomic density increases and the concentration of microvoids decrease in a-Si:H films. The increase of both the short range order and the intermediate range order of amorphous network for a-Si:H films were verified by Raman scattering spectra, in which increasing Ts decreasing the band width of TO and the scattering intensity ratio I TA /I TO were obtained. All above results clarify the effect of increasing Ts on the microstructure amelioration for a-Si:H films. The reduction of disordered domains is correlated with the film growing process, where the increased surface diffusion mobility and etching of weak bonds is induced by increasing Ts. Furthermore, analysis of optical absorption indicates that the films with a lower optical band gap and a narrower band edge can be obtained by this FTS technique. hydrogenated amorphous silicon, facing target sputtering, structural inhomogeneities, microvoids PACS: 81.05.Gc, 81.15.Cd, 78.30.Er

Structural evolution and electronic properties of n-type doped hydrogenated amorphous silicon thin films

“…2 (c) that the systematical changes in stretching vibration intensity do not occur as a function of T s , which differs from the results reported by other groups [15]. However, the microstructural factor R in our experiment, as shown in Table 3 and that of void or disordered domains, because the hydrogen atoms located in these region is in the configuration of (SiH 2 ) n (or SiH 2 ) or (SiH) n .…”

Effect of RF power on the properties of intrinsic hydrogenated amorphous silicon passivation layer deposited by facing target sputtering

“…24) FTS has already been used for the low-damage and high-rate deposition of TCO, metal, metal oxide, and magnetic materials. [25][26][27][28][29] Although the deposition of a-Si:H by FTS was reported by Wei et al, 30) the passivation quality of a-Si:H deposited by FTS on c-Si has not been reported yet. In this study, we investigated the effect of RF power on the c-Si surface passivation quality of i-a-Si:H deposited by FTS.…”