Enhancement of Ag sintering reactions through high-density (111) orientation Ag nanotwins for the die bonding of SiC chips with DBC alumina substrates

Abstract

Ag sintering has become a preferred die bonding method for power IC packages due to its exceptional thermal, mechanical, and electrical properties. While it is widely recognized for its potential in high-power semiconductor applications, few research efforts have emerged that consider how the backside metallization films of the IC can enhance the sintering layer’s properties. This research focused on the enhancement of silver sintering for bonding of Cr/Ni/Ag and Cr/nanotwinned Ag-metallized film on silicon carbide (SiC) chips to direct bonded copper (DBC) substrates to investigate the beneficial effects of (111)-textured Ag nanotwinned films on the bonding strength increase and porosity reduction. Results reveal that the nanotwinned Ag films significantly reduce porosity and enhance bonding strength compared to conventional Cr/Ni/Ag films, under both pressurized and pressureless conditions. Implications for the improvements in reducing porosity and increasing bonding strength due to the nanotwin structure and further research are also discussed, opening new possibilities for advanced power electronic packaging technology.