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In situ B‐doped Si epitaxial growth at low temperatures by atmospheric‐pressure plasma CVD
Author(s) -
Kirihata Y.,
Nomura T.,
Ohmi H.,
Kakiuchi H.,
Yasutake K.
Publication year - 2008
Publication title -
surface and interface analysis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.52
H-Index - 90
eISSN - 1096-9918
pISSN - 0142-2421
DOI - 10.1002/sia.2835
Subject(s) - epitaxy , doping , analytical chemistry (journal) , chemical vapor deposition , substrate (aquarium) , materials science , atmospheric pressure , chemistry , nanotechnology , optoelectronics , layer (electronics) , organic chemistry , oceanography , geology
In situ B‐doped Si epitaxial growth by atmospheric‐pressure plasma chemical vapor deposition (AP‐PCVD) using porous carbon electrode was investigated. Heavy B doping for a carrier concentration of 8 × 10 19 cm −3 was achieved using B 2 H 6 as a doping gas, with a high average growth rate of 0.20 µm min −1 at 570 °C. The relation between the hole mobility and carrier concentration in heavily B‐doped Si films can be well fitted with that reported for bulk Si single crystals up to the carrier concentration of 5 × 10 19 cm −3 . This result demonstrates that the electrical quality of heavily doped Si epitaxial films grown by AP‐PCVD is sufficiently high for semiconductor device applications. The activation ratio of B atoms as acceptors in the heavily doped films is nearly 100% for a carrier concentration range reaching approximately 2 × 10 19 cm −3 . Cross‐sectional transmission electron microscopy examination of heavily B‐doped epitaxial Si with a carrier concentration of 2 × 10 19 cm −3 revealed both a defect‐free film and film/substrate interface. In the present experiment, the required B 2 H 6 /SiH 4 ratio is much higher than the resultant B composition in the Si films, due to thermal decomposition of B 2 H 6 molecules in the porous carbon electrode. To increase the efficiency of B 2 H 6 gas usage, cooling of the porous carbon electrode during the AP‐PCVD process may be effective. Copyright © 2008 John Wiley & Sons, Ltd.