Analysis of Defect Distribution in Transistor Structures with Reflection and Transmission X-Ray Topography

Reflection and transmission x-ray topography can be combined to isolate and identify dislocations that penetrate the active junctions of transistor structures in integrated circuit wafers. This is accomplished by reconstructing the defect distribution normal to the surface as viewed in transmission (volume-sensitive) and reflection (surface-sensitive) x-ray topography. The combination of surface and bulk observations is exploited to demonstrate the effect of dislocation density on pipes (low-resistance paths from emitter to collector). A method is also described for estimating the depth of defect visibility in reflection x-ray topography.