Fabrication of high quality GaAs-on-insulator via ion-cut of epitaxial GaAs/Ge heterostructure

- GaAs-on-insulator has been achieved by integrating of epitaxy, ion-cut and selective chemical etching.
- Superior to the direct ion-cut of bulk GaAs layer with the H implantation fluence 2.0 × 1017 cm−2, the fabrication of GaAs-on-insulator by the transfer of GaAs/Ge heterostructure only needs H implantation fluence as low as 0.8 × 1017 cm−2.
- The crystalline quality of the top GaAs layer of the final GaAs-on-insulator wafer is not affected by the implantation process and comparable to the as-grown status.

Due to the extraordinary electron mobility, III-V compounds are considered as the ideal candidate channel materials for future electronic devices. In this study, a novel approach for the fabrication of high-crystalline quality GaAs-on-insulator has been proposed by integrating of ion-cut and selective chemical etching. GaAs layer with good crystalline quality has been epitaxially grown on Ge by molecular beam epitaxy (MBE). With H implantation and wafer bonding process, the GaAs/Ge heterostructure is transferred onto silicon dioxide wafer after the proper thermal treatment. Superior to the direct ion-cut of GaAs layer, which requires the H implantation fluence as high as 2.0 × 1017 cm−2, the transfer of GaAs/Ge heterostructure in the present study only needs the implantation of 0.8 × 1017 cm−2 H ions. GaAs-on-insulator structure was successfully achieved by the selective chemical etching of defective Ge layer using SF6 plasma. As the GaAs/Ge heterostructure can be easily epitaxy grown on silicon platform, the proposed approach for GaAs-on-insulator manufacturing is rather compatible with mature Si integrated circuits (ICs) technology and thus can be integrated to push the microelectronic technology to post-Si era.