Hybrid bonding techniques for multi-layer semiconductor stacks

A circuit arrangement and method utilize hybrid bonding techniques that combine wafer-wafer bonding processes with chip-chip and/or chip-wafer bonding processes to form a multi-layer semiconductor stack, e.g., by bonding together one or more sub-assemblies formed by wafer-wafer bonding together with other sub-assemblies and/or chips using chip-chip and/or chip-wafer bonding processes. By doing so, the advantages of wafer-wafer bonding techniques, such as higher interconnect densities, may be leveraged with the advantages of chip-chip and chip-wafer bonding techniques, such as mixing and matching chips with different sizes, aspect ratios, and functions.