Growth of Structures for Integrated Optoelectronic Devices.

摘要

Low-pressure metalorganic chemical vapor deposition (LPMOCVD) has been used to grow GaAs epitaxially on GaAs substrates by reacting triethylgallium and arsine. Various deposition parameters such as substrate temperature, total pressure, and V/III ratio were varied systematically. Optical and scanning electron microscopy revealed the presence of oval defects. Photoluminescence shows bandgap luminescence at 1.5 eV. Hall effect data indicate that the deposited GaAs is p-type with a carrier concentration of 10(exp 17) /cu cm and a mobility of 275 sq cm/V.s at room temperature. Secondary ion mass spectrometry analysis shows a high concentration of carbon that acts as a shallow acceptor. Raman spectroscopy shows that the ratio of the intensity of the LO to the TO mode is much larger for the deposited GaAs epilayer than for the bare substrate using the same scattering geometry. Thin films, GaAs, Low-pressure MOCVD.