The Nucleation of CVD Silicon on SiO2 and Si3 N 4 Substrates III . The System at Low Temperatures

TLDR: In this article, the saturation nucleus density of polycrystalline silicon layers on and substrates was investigated at temperatures between 600° and 900°C and it was shown that selective growth of silicon on partly coated silicon substrates becomes more difficult at lower growth temperatures.

Abstract: The growth of polycrystalline silicon layers on and substrates can be hampered in the early stages of growth by the presence of different species adsorbed on the surface In this article nucleation experiments with silicon on and are described in the system at temperatures between 600° and 900°C In this temperature regime (and without addition) the saturation nucleus density of silicon clusters on substrates shows a decrease in density with decreasing temperature, whereas on substrates the opposite occurs Experiments with nitrogen as a carrier gas, however, give almost the same saturation nucleus densities of silicon clusters on and substrates Additions of to the system produce a decrease in the nucleus saturation density on and substrates, and the density also decreases with decreasing temperatures below 900°C It is further shown that selective growth of silicon on partly coated silicon substrates becomes more difficult at lower growth temperatures Adsorption of different surface species (H, Cl, , and ) on and substrates is discussed and it is concluded that a strong adsorption of atomic hydrogen, notably on surfaces, may explain the difference in nucleus densities on and substrates at temperatures below 900°C