This is only applicable to die photographs of the silicon layer. For CT scans, which use X-rays, the visible structure is very likely due to the metallic (copp

This is only applicable to die photographs of the silicon layer. For CT scans, which use X-rays, the visible structure is very likely due to the metallic (copper) interconnect, clock- and power-delivery layers, which are generally quite different from the underlying transistors. These layers are larger-scale, and copper also absorbs X-rays much more strongly than silicon.