Microstructural and in turn functional failure of Si3N4 metal-insulator-metal (MIM) capacitors fabricated by plasma enhanced chemical vapor deposition was investigated using cross-sectional transmission electron microscopy and residual stress analysis. As a result it was manifested that the failure of the Si3N4 MIM capacitors was caused by microvoids formed over the Si3N4 dielectric and the TiN interlayer adopted for the use of diffusion barrier. The microvoid having occurred at the MIM capacitor with very thin Si3N4-less than 50 nm. thick in the present article caused it to leak out much of the current to the extent of a few microamperes even at bias of 3 V. The microvoid, one of the important constraints in the fabrication of high capacitive Si3N4 MIM capacitors, was explained by the residual stress of the constituent layers. The stress analysis showed that the absolute stress normalized by the thickness of the Si3N4 layer should be less than 30 MPa/nm to avoid microvoiding. In this research we noted that the stress state of not only the dielectric but also the interlayer should be taken into account for the successful design of high capacitive SO4 MIM capacitors.