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SIMS and X‐ray diffraction characterization of carbon‐doped GaAs, Al x Ga 1 − x As films grown by MBE
Author(s) -
Gerardi C.,
Giannini C.,
Tapfer L.,
Fischer A.,
Ploog K. H.
Publication year - 1994
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.740220180
Subject(s) - molecular beam epitaxy , carbon fibers , analytical chemistry (journal) , dopant , hall effect , diffraction , impurity , doping , secondary ion mass spectrometry , interstitial defect , substrate (aquarium) , acceptor , chemistry , x ray crystallography , x ray absorption spectroscopy , materials science , crystallography , epitaxy , ion , absorption spectroscopy , nanotechnology , optoelectronics , condensed matter physics , optics , electrical resistivity and conductivity , physics , layer (electronics) , oceanography , composite number , composite material , chromatography , quantum mechanics , organic chemistry , geology
In this article we report on analyses of GaAs and Al x Ga 1 − x As carbon‐doped films, grown by solid source molecular beam epitaxy by using secondary ion mass spectrometry, x‐ray diffraction, and Hall effect measurement. Carbon is an amphoteric dopant, i.e. it behaves as an acceptor or a donor impurity when it occupies an As or a Ga site, respectively. Comparison between x‐ray diffraction and Hall effect measurements indicates that, for concentrations below 4 × 10 19 cm −3 , carbon is preferentially incorporated on As site, both in GaAs and Al x Ga 1 − x As layers. We find that the presence of Al strongly enhances the substitutional carbon incorporation. SIMS analyses show that the total amount of carbon largely exceeds the substitutional carbon content recorded by HRDXD. The results can be explained considering that carbon is on substitutional as well as interstitial sites. Furthermore, we show that the interstitial carbon concentration can be reduced for both GaAs:C and Al x Ga 1 − x As:C growing at an increased As 4 flux and higher substrate temperature.