Spatially resolved Raman investigation of Si-doped GaAs layers on patterned GaAs(100) substrates grown by molecular beam epitaxy

Autor: Rolf Sauer, C. Ehret, J.M. Schneider, Wolfgang Limmer, H. Heinecke, J. Gerster
Rok vydání: 1997
Předmět:
Zdroj: Microelectronics Journal. 28:985-992
ISSN: 0026-2692
DOI: 10.1016/s0026-2692(96)00138-3
Popis: Local carrier transport properties of Si-doped GaAs layers on ridge structures exhibiting (111)A and (111)B sidewalls are investigated. The layers were grown by molecular beam epitaxy at different substrate temperatures and As/Ga flux ratios. Using spatially resolved Raman spectroscopy we determine the type and density of free charge carriers (≥ 5 × 10 17 cm −3 ) in the grown layers on the different index facets from an analysis of the coupled plasmon-longitudinal optical-phonon mode which was calibrated against Hall standards. We demonstrate that on the (100) and (111)B facets the regrown layers are n-type and on the (111)A facets p- or n-type depending on the growth conditions. Line scans of the carrier density show that the (100)/(111)A/(100) facet transition forms a graded lateral n-p-n junction. Spatially resolved photoluminescence measurements confirm our findings.
Databáze: OpenAIRE