Advances in Low-Temperature Bonding Technologies for 3D Integration

摘要

Since the observation of Newton's rings in optical contacts, the technologies of bonding, or the adhesion of two objects, have made great progress in terms of their applications, methodologies, and related areas of fundamental science. Among the various bonding methods, those involving low-temperature bonding (LTB) are important because of their application to the fabrication of systems with low tolerances against thermal stresses and their short turnaround time. LTB is now leading to entirely new manufacturing approaches to three-dimensional (3D) and heterogeneous integration, not only for semiconductor devices and microsystems but also for energy systems and power devices; LTB-based micro-electro-mechanical-system modules such as pressure sensors and acceleration sensors have been developed and are now commercially available. The possibilities of 3D-LSIs, hybrid ICs, and tandem solar cells, as well as engineering substrates for optical and power devices using LTB technologies are currently being investigated. Novel methods of LTB and the characterization of bonding interfaces have been continuously proposed and their validity has been examined.