Research on XOI Heterogeneous Integration Materials for the Post-Moore Era

　　In the future, microelectronics, optoelectronic devices, and intelligent microsystems will continue to evolve toward miniaturization, integration, and intelligence. The required functionalities of microsystem chips will become increasingly complex, diversified, and seamlessly integrated. This development trend places enormous demands on heterogeneous integration technologies. Heterogeneous integration will also open up an entirely new path for the advancement of microelectronics in the post-Moore era. By building upon the existing device and process dimensions, it will enable the development of integrated technologies that combine heterogeneous materials with multifunctional devices, thereby achieving functional diversification within a single chip—particularly enabling the monolithic integration of optoelectronic, microenergy, analog, radio-frequency, passive, and MEMS devices on a single chip. To advance heterogeneous integration technologies, the first critical challenge is to address the issue of heterojunction formation between different semiconductor materials and functional thin films. This will lay a crucial material foundation for realizing monolithic integration of devices and systems in the future. In terms of material heterojunction integration, traditional epitaxial growth methods—such as molecular beam epitaxy, metal-organic chemical vapor deposition, chemical vapor deposition, physical vapor deposition, and magnetron sputtering—suffer from issues including lattice mismatch, crystal-phase mismatch, mutual diffusion, and reverse domain formation, all of which severely compromise film quality and the flexibility of heterogeneous integration. By contrast, ion-beam exfoliation and transfer technology allows for the exfoliation of nanoscale-thick films from any single-crystal substrate and their subsequent combination with heterogeneous materials. This approach breaks through the physical limits of conventional heteroepitaxial growth, enabling the integration of high-quality single-crystal films onto amorphous, polycrystalline, and even flexible substrates. It thus provides a simple and efficient means for achieving high-quality heterogeneous integration materials. Ion-beam exfoliation technology has already achieved remarkable success in the preparation of silicon-on-insulator (SOI) materials on insulating substrates. This report will introduce the application of this technology in the fabrication of wafer-level XOI (X = III-V compounds, wide-bandgap semiconductors, and functional thin films) heterogeneous integration substrates.

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