Improvement on the Gate Oxide Integrity Caused by the Tub Charges in SOI Technology

Abstract—This paper describes the journey of understanding and improving the gate oxide integrity for SOI (Silicon on Insulator) technology. Investigation shows that the influence of charges within a tub plays a significant role in the gate oxide breakdown. The well charges are influenced by the processes in the ONO (Oxide-Nitride-Oxide) process loop. The charges affect the surface bonding which defines the surface wettability and hence the cleaning efficiency. Using O2 plasma treatment to modify the surface bonding is proven to be a robust solution for this gate oxide issue.