Shallow levels characterization in epitaxial GaAs by acousto-optic reflectance
Optical spectra of light refl ection are detected under an infl uence of ultrasonic wave (UW)on a GaAs wafer. The differential spectrum is calculated as a difference between those takenunder UW and without that infl uence on a sample. This acousto-optic differential refl ectance(AODR) spectrum conta...
| Autores: | , , , , , , , , , , , , , , |
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| Tipo de recurso: | artículo |
| Estado: | Versión publicada |
| Fecha de publicación: | 2005 |
| País: | México |
| Institución: | Universidad de Guanajuato |
| Repositorio: | Redalyc-UG |
| OAI Identifier: | oai:redalyc.org:41615204 |
| Acceso en línea: | https://www.redalyc.org/articulo.oa?id=41615204 |
| Access Level: | acceso abierto |
| Palabra clave: | Multidisciplinarias (Ciencias Sociales) Semiconductors Shallow levels Optical refl ectance |
| Sumario: | Optical spectra of light refl ection are detected under an infl uence of ultrasonic wave (UW)on a GaAs wafer. The differential spectrum is calculated as a difference between those takenunder UW and without that infl uence on a sample. This acousto-optic differential refl ectance(AODR) spectrum contains some bands that represent the energetic levels of the shallowcenters in a sample. A physical basis of this technique is related to a perturbation of localstates by UW. Here, a method is developed for characterization of local states at the surfacesand interfaces in crystals and low-dimensional epitaxial structures based on microelectronicsmaterials. A theoretical model is presented to explain AODR spectra. Also, experimentsusing epitaxial GaAs structures doped by Te were made. Finally, theoretical and experimentalresults show that acousto-optic refl ectance is an effective tool for characterization of shallowtrapping centers in epitaxial semiconductor structures. |
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