The global trend towards IoT and smart sensor systems makes heterogeneous 3D integration a key technology, but also brings challenges for the corresponding process technologies, such as aligned die-to-wafer stacking and wafer bonding: The immense competitive pressure in IoT applications demands ever smaller, but at the same time more powerful and robust systems.
To meet these requirements, Fraunhofer EMFT signed a licensing agreement with XPERI Corp. in September 2016 and included ZiBond® and DBI® (Direct Bond Interconnect), two of the most advanced 3D integration technologies, in its portfolio of services.
Both processes can be carried out at comparatively low temperatures of around 200 °C, which has a positive effect on component reliability and service life. In DBI® technology, the components are joined both mechanically and electrically after special pretreatment of the copper and oxide surfaces used. Since this eliminates the time-consuming process of through-hole plating of chips, the systems can be manufactured more cost-effectively - a basic prerequisite for accessing mass markets such as consumer electronics. Another advantage is that the "pitches" (structure width and spacing) between the interconnections are only 2 μm in the best case. This enables highly integrated systems-on-chips with enormous performance. This is of great interest for high-performance applications such as processors. An important trend in this area is, for example, so-called hybrid memory cubes - i.e. memory and processor components integrated in a 3DIC stack.