کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
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5368962 | 1388414 | 2009 | 4 صفحه PDF | دانلود رایگان |

We systematically investigate adsorption behavior of Al and N atoms on 4H-SiC (112¯0) surfaces based on first-principles calculations. The calculations for stable adsorption site demonstrate that the Al atom is adsorbed at the lattice site of 4H structure whereas the N atom is incorporated at the interstitial site. The calculated surface phase diagrams for Al and N atoms as functions of beam equivalent pressure and temperature clarify that Al atoms can be adsorbed at all of the adsorption sites below 1800 K and N atoms, in contrast, are desorbed excepting the most stable site above 1150 K. These temperatures imply that under experimental conditions (1223 K) Al atoms can be easily adsorbed and N atoms are adsorbed only on the most stable adsorption site. Furthermore, the calculated barrier heights of adsorbed Al and N atoms are 1.0 and 1.8 eV, respectively, implying that the surface migration of Al atoms is prominent compared to that of N atoms. These results obtained thus manifest that adsorption behavior of Al and N atoms is quite different and the growth processes change depending on V/III ratio under molecular beam epitaxy growth.
Journal: Applied Surface Science - Volume 256, Issue 4, 30 November 2009, Pages 1160-1163