"Low-temperature direct bonding of nanocrystalline nanotwinned Ag thin films for advanced packing technology"
With the development of the microelectronic industry, three-dimensional integration technology has been regarded as a prominent method to achieve the smaller featured size and higher performance for the consumer electronic market. The application environment becomes harsher for high power or high switching frequency applications such as electric vehicles or 5G communications. As the scaling of solder-based micropumps and harsher application environment, many new reliability issues have emerged for solder-based interconnection, which makes the traditional soldering process unsuitable for interconnections in electronic devices. Recently, metal-to-metal direct bonding technology has drawn a lot of attention to achieve wafer-level bonding for heterogeneous integration in next-generation power devices and 3D IC technology.
This talk will focus on the development of low-temperature direct bonding of nanocrystalline and nanotwinned Ag thin films for advanced packing technology. Firstly, I will talk about the issues of solder joint technology when the size/pitch of the bumps continues to scale down. Then, I will describe the key factors to achieve metal-to-metal direct bonding. Next, I will discuss how to integrate chips at low temperatures under an air atmosphere and why nanocrystalline Ag and nanotwinned Ag thin films play a vital role in low-temperature direct bonding technology. The corresponding bonding mechanism, bonded mechanical strength, electrical performance, and reliability will be discussed in detail.