Quasihomogeneous wafer bonding for fusing dissimilar materials via nanoscale homogenization layer deposition

Abstract

Hybrid bonding, which is partially based on heterogeneous wafer bonding, is a critical process for integrating various functional devices onto a chip, advancing cutting-edge technologies. However, heterogeneous wafer bonding often faces challenges due to mismatches in the physical and chemical properties of dissimilar materials. This study demonstrates the transformation of heterogeneous wafer bonding into quasihomogeneous wafer bonding via a nanoscale homogenization layer, which significantly enhances bonding compatibility. High-energy sputtering is used to deposit aluminum nitride (AlN) atomic clusters onto silicon carbide (SiC) surfaces, forming a nanoscale AlN layer that enhances bondability by increasing the density of dangling bonds through surface-to-volume effects. This homogenization approach also induces strong capillary forces, driven by the nanoscale surface effect, to enable robust bonding on surfaces with a roughness exceeding 5 Å. By addressing critical barriers in SiC and AlN integration, this quasihomogeneous bonding technique facilitates strong fusion bonding between chemically incompatible surfaces. This study underscores the transformative potential of nanotechnology in wafer bonding technology, providing insights into enhancing hydrophilic bonding capabilities. Furthermore, it offers a scalable solution for semiconductor packaging and high-performance electronic or ceramic material applications, paving the way for advanced wafer-to-wafer and chip-on-wafer hybrid bonding technologies.