ISSN:
1077-3118
Source:
AIP Digital Archive
Topics:
Physics
Notes:
Semi-insulating polycrystalline silicon films, deposited by low-pressure chemical vapor deposition on oxidized Si substrates at O concentrations from 2 up to 35 at. % O, have been annealed at 920 °C for 30 min. Transmission electron microscopy revealed the presence of crystalline Si grains. The average Si grain radius decreases with O content going from ≈15 up to ≈2 nm, while electrical resistance increases with O concentration of almost four orders of magnitude. We attribute the resistance increase at large O contents to the presence of SiO2 shells, two monolayers thick, covering the Si grains. At these large O contents a noticeable increase in Si grain size and electrical conductance is observed in samples annealed at 1200 °C for 30 min. These results can be interpreted on the basis of thermal instability of the oxide shells. This assumption is supported by observations of native oxide breaking against high-temperature annealings.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1063/1.110027
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