Grafted semiconductor optoelectronics

A description is given of the use of epitaxial lift-off (ELO) for optoelectronics. With ELO, a high-quality GaAs-AlGaAs or InP_0.53 Ga_0.47As film is removed from its growth substrate by selective etching and then grafted to a new substrate, through van der Waals forces, where it is used for device fabrication. The semiconductor devices are made completely on the new substrate so they can be photolithographically aligned and batch processed. Details of the ELO procedure and subsequent grafted device fabrication are presented. The authors establish that the grafted film is in optical contact with the new substrate, and they describe devices, such as an LiNbO₃ waveguide detector and a GaAs-glass waveguide grating coupler, which are based on this coupling. Besides photodetectors, grafted GaAs field-effect transistors, another important component for optoelectronics that show DC and RF performances similar to those of devices made on the growth wafer are also described