H. Tanaka et al., THE DEGRADATION OF TDDB CHARACTERISTICS OF SIO2 SI3N4/SIO2 STACKED FILMS CAUSED BY SURFACE-ROUGHNESS OF SI3N4 FILMS/, I.E.E.E. transactions on electron devices, 40(12), 1993, pp. 2231-2236
The effect of surface roughness of Si3N4 films on TDDB characteristics
of SiO2/Si3N4/SiO2 (ONO) stacked films was investigated. The surface
roughness of Si3N4 films was found to become higher with increasing th
e deposition temperature and to cause the degradation of TDDB characte
ristics of ONO films. A local thinning of ONO films, evaluated from th
e TDDB characteristics, agreed with the surface roughness measured by
AFM add XTEM. Dependence of time to breakdown of ONO films on the depo
sition conditions was interpreted by electric field intensification du
e to the surface roughness of Si3N4 films.