Growth velocity variations during metalorganic vapor phase epitaxy through an epitaxial shadow mask

Abstract
A novel shadow masking technique is proposed for the local variation of growth velocity in GaAs/AlGaAs structures grown on GaAs by metalorganic vapor phase epitaxy. This mask makes use of epitaxially grown spacer and mask layers and windows in the mask are lithographically defined. This results in a highly accurate and reproducible shadow mask which can be removed by lift-off. Growth velocity variations up to 50% have been observed. The application of this technique to the coupling of passive and active waveguide structures is proposed.