Low temperature SiCN as dielectric for hybrid bonding

Abstract

For various 3D integration schemes, such as Collective Die to wafer stacking (CoD2W) and Die to wafer (D2W) bonding, the thermal budget needs to be well below 250°C due to the presence of temporary bonding materials. In this paper we, present a new PECVD SiCN layer deposited at 175°C, optimized for hybrid bonding applications. The layer provides void-free wafer to wafer bonding interface demonstrated by high bond strength even at a post bond annealing (PBA) temperature of 200°C and devoid of any outgassing voids until 350°C. Additionally, it has been verified that the layer has excellent moisture and as electrical barrier properties.