ENHANCED HOT-CARRIER DEGRADATION DUE TO WATER-RELATED COMPONENTS IN TEOS/O3 OXIDE AND WATER BLOCKING WITH ECR-SIO2 FILM

A TEOS/O3-oxide layer used as an interlevel dielectric enhances hot-carrier degradation of MOSFET's due to the water-related components (water and/or silanols) contained in the layer. This results mainly from enhanced hot-electron trapping in the gate oxide and also from interface-trap generation. By applying an ECR-SiO2 layer under the TEOS/O3-oxide layer, tolerance against hot-carrier damage is improved to the level of MOSFET's without the TEOS/O3 oxide. From ESR measurement results, it is found that the spin density of the ECR-SiO2 film under the TEOS/O3 oxide was two orders lower than that of the ECR-SiO2 film only. It is speculated that the dangling bonds in the ECR-SiO2 film effectively trap water diffusing from the water-containing over-layer.