Backside Power Distribution for Nanosheet Technologies Beyond 2nm

This paper examines various approaches for integrating backside power distribution network (BSPDN) with nanosheet transistor technologies. Deep Trench Via (DTV) based BSPDN schemes, except for Shifted Frontside Via Backside Power rail (SFVBP), do not offer cell level scaling benefits, but via resistance of SFVBP could remain a bottleneck. Direct Backside Contact (DBC) based schemes offer best cell level scaling. A novel self-aligned backside contact (SABC) scheme integrated with nanosheet transistors is demonstrated with immunity to misalignments in backside contact formation. The structure exhibits good device characteristics and satisfactory reliability.