Remote plasma-enhanced CVD of silicon: Reaction kinetics as a function of growth parameters

Plasma chemistry aspects of a-Si:H deposition using an expanding thermal plasma

“…13 There is a distinct difference between argon and helium diluted remote plasmas. The recent appearance of potential mass spectrometry measurements of a He/SiH 4 remote rf inductively coupled plasma has revealed that the dominant specie in this type of plasma is the silyl radical, 10 in agreement with modeling results by Kushner. 15 On the other hand Ar/SiH 4 remote plasmas seem to favor higher silanes and powder formation which might explain the bad a-Si:H quality deposited utilizing this type of plasma.…”

“…32 As is known for the expanding thermal arc plasma, the electron temperature in the region where silane is injected, as measured using Langmuir probes and Thomson scattering, is around 2000-3000 K, i.e., much lower than the mean electron temperatures in active plasmas. [20][21][22][23][24][25] In fact the dissociation of silane in the pure argon case shows similarities with the reported results on helium and argon remote plasmas by the group of Lucovsky et al, 9 Anthony et al, 10 Jasinski, 12 Theil and Powell 11 and modeled by Kushner. 15 Here we will develop the analysis as proposed by these researchers further by a systematic analysis of the silane dissociation channels possible.…”

“…In the past other types of remote plasmas have been used to deposit high quality a-Si:H films. [9][10][11][12][13] The major advantage of remote plasma is the absence of direct plasma contact with the substrate and therefore absence of ionic species ͑with possible high energy ions͒ and ultraviolet ͑UV͒ radiation. This leads to less surface damage and bulk defects which could be advantageous for radical dominated plasma deposition processes such as a-Si:H deposition.…”

“…Lucovsky and co-workers, 9 Anthony et al 10 and Theil and Powell 11 have utilized a rf inductively coupled plasma whereas Jasinski 12 and Johnson and co-workers 13 utilized a microwave induced remote plasma for the deposition of a-Si:H. Major drawbacks of these plasma sources are the reported low a-Si:H growth rates, usually in the range of 0.01-0.05 nm/s. [9][10][11][12][13] In the literature discussion about the possible precursor for growth from remote rare gas ͑He, Ar͒ diluted silane plasmas has ranged from exotic precursors as highly excited silane 14 to silicon centered radicals. 12,15 The situation seems more clear for hydrogen diluted microwave plasmas where atomic hydrogen is the reactive specie which abstracts hydrogen from silane to form mainly silyl radicals (SiH 3 ) and molecular hydrogen.…”

Atmospheric Plasma Deposition of Coatings Using a Capacitive Discharge Source

“…[68] Other groups have reported deposition rates ranging from 0.5 nm min ±1 to 3.5 nm min ±1 using an ICP source operating under 0.2 torr and with a 200 C substrate temperature. [97,98] These results may be compared to the present study, where a deposition rate of 6.5 nm min ±1 was recorded under atmospheric pressure and at 200 C. It should be noted that rates as high as 600 nm min ±1 have been achieved with an expanding thermal plasma (cascaded arc) which, although a remote system, has a high density of ionic and thermally activated species that can be involved in the gas phase reactions. [99] Shown in Figure 10 is the dependence of the hydrogen content on the H 2 pressure.…”