Characterization of patterned oxide buried in bonded silicon-on-insulator wafers by near-infrared scattering topography and microscopy

A patterned oxide buried in bonded silicon-on-insulator (SOI) wafers before thinning has been characterized using a near-infrared scattering topography system. This system has been combined with transmission and reflection microscopy. The edge of the patterned oxide buried in the SOI wafer has been observed. Micron-scaled oxide disks formed by the focused ion beam technique in stacked SOI structures have been observed by near-infrared scattering topography. A particle has been identified to be located inside a silicon/air/silicon structure by both near-infrared and visible laser scattering topographies. The size of the particle inside the silicon/air/silicon structure has been estimated to be 0.2 μm from the intensity of scattered near-infrared light. This method has an advantage over semiconductor failure analysis in future scaled-down technologies.