OXIDE DEGRADATION OF WAFER BONDED METAL-OXIDE SEMICONDUCTOR CAPACITORS FOLLOWING FOWLER-NORDHEIM ELECTRON INJECTION

The degradation of wafer bonded silicon dioxides as a result of Fowler-Nordheim electron injection has been studied. The samples were metal oxide semiconductors (MOS) capacitors with wafer-bonded SiO2-SiO2 interfaces at the oxide center. The charge trapping in the oxide and the Si-SiO2 interface state generation were monitored as a function of injected charge and compared to reference MOS capacitors without bonded interfaces. A larger change in the oxide charge was found in the bonded capacitors as compared to the reference structures. The centroid of trapped negative oxide charge was found to be located close to the SiO2-SiO2 interface in the bonded structures, while the reference structures exhibited centroids close to the injecting contact. The electron injection caused approximately the same generation of interface states in both groups of capacitors.