| Autor: |
Karen L. Kavanagh, C. X. Wang, Simon P. Watkins, V. Fink, O.J. Pitts |
| Rok vydání: |
2003 |
| Předmět: |
|
| Zdroj: |
Journal of Crystal Growth. 254:28-34 |
| ISSN: |
0022-0248 |
| DOI: |
10.1016/s0022-0248(03)01164-3 |
| Popis: |
Sb segregation effects have been studied in structures grown by organometallic vapor phase epitaxy. The structures are formedby periodic exposure of the GaAs (0 0 1) surface to trimethylantimony (TMSb), followedby GaAs growth. Reflectance-difference spectra obtained during growth show a strong influence of Sb on the surface reconstruction, reducing the concentration of As dimers. Transmission electron microscope images and X-ray diffraction (XRD) measurements show that a periodic multiple quantum well (MQW) structure is formed by the TMSb/GaAs growth sequence. A fraction of the deposited Sb is incorporated as a one monolayer thick Sb-rich quantum well in each period. The incorporation of impurity Sb, as the GaAs layers are grown, results in the formation of a graded GaAs1� xSbx barrier layer above each QW layer. The impurity profile inferredfrom XRD measurements is in goodagreement with a one-dimensional segregation model based on the partitioning of Sb between the growing barrier layer and a surface floating layer. The Sb floating layer is shown to desorb under exposure to tertiarybutylarsine. r 2003 Elsevier Science B.V. All rights reserved. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
|
Full Text from ScienceDirect