Spatial Distribution of SiH₃ Radicals in RF Silane Plasma

Abstract

Infrared diode laser absorption spectroscopy (IRLAS) was applied to the measurement of SiH3 in a RF silane P-CVD chamber with parallel plate electrodes. The spatial distribution of SiH3 radicals between the electrodes was measured to obtain the incident flux density of SiH3 to the electrode surface. The growth rate of a-Si:H was also measured in the same plasma. These data were used to estimate the contribution of SiH3 to a-Si:H thin-film growth.

From High-Resolution Spectroscopy to Chemical Reactions

“…For this type of cell, we may determine the concentrations of fragment molecules as functions of the distance from the surface of the base electrode on which amorphous silicon grows. This observation, com bined with the diffusion coefficient we determined, led us to conclude that the main process of producing amorphous silicon took place through the SiR3 radical (64).…”

Thin-Film Silicon –Growth Process and Solar Cell Application–

“…Steady-state densities of reactive species have been measured using various gas-phase diagnostic techniques [10][11][12][13][14][15][16] such as optical emission spectroscopy (OES), 14) laser-induced fluorescence (LIF), 12,15) infrared-laser-absorption spectroscopy (IRLAS), 10,11) and ultraviolet light-absorption spectroscopy (UVLAS). 16) Figure 3 shows the steadystate number densities of neutral chemical species including emissive species in the realistic SiH 4 and SiH 4 /H 2 plasmas used for preparing device-grade a-Si:H and c-Si:H. Figure 4 shows a linear relationship between the deposition rate of c-Si:H as well as that of a-Si:H and the Si à -emission intensity from the plasma, and also one-to-one correspondence between those deposition rates and number density of SiH 3 radicals in the plasma.…”

Time-resolved cavity ringdown study of the Si and SiH3 surface reaction probability during plasma deposition of a-Si:H at different substrate temperatures

“…6,7,10,30,31 They constructed a first growth model of a-Si: H with several possible surface reactions of the SiH 3 radical, based on indications that SiH 3 has the highest density of all reactive species in the SiH 4 plasma. 32,33 The model was derived primarily from measurements of the deposition rate and the overall surface reactivity for changing substrate temperature 6 and doping gas concentration, 7 where the overall surface reactivity was measured using the aforementioned indirect method of evaluating the conformality of deposition profiles. The surface reaction probability ␤ was introduced as the probability that a plasma radical, such as SiH 3 , will react at the surface.…”