MOCVD GROWTH OF INXGA1-XAS GAAS MULTIPLE-QUANTUM-WELL AND SUPERLATTICE STRUCTURES FOR OPTICAL MODULATORS/

Semiconductor epitaxial structures were designed for use in an optical modulator in the 980 nm wavelength region. Strained InxGa1-xAs/GaAs s uperlattices and multiple quantum wells were chosen for the optically active part of the modulator as they can be tailored for the desired w orking wavelength. The optically active region was embedded in a PIN p hotodiode structure. Test InxGa1-x As/GaAs structures were prepared by low pressure metalorganic chemical vapor deposition (LP-MOCVD). The I nxGa1-xAs composition was determined by X-ray diffractometry, and it w as confirmed by photoluminescence spectroscopy. Photoreflectance spect roscopy was employed to determine energy level positions in the quantu m wells. The quality of the samples was checked by photoluminescence. Photocurrent spectroscopy was used for the characterization of electro -optical properties of the structures. Their suitability for optical m odulation was discussed. (C) 1998 Elsevier Science Ltd. All rights res erved.