Chipworks definitely has some fancy equipment inside their labs. They took apart one of their iPhone 4S units this morning (using our teardown for guidance, of course) and tossed the 8MP camera directly under an infrared microscope to find out the manufacturer.
The infrared microscope allowed them to look through the whole structure down to the base layer. They saw die markings several layers below the surface.
So what did they see? S O N Y.
The pictures below are of the Sony designation inside the camera. Note that the camera itself is significantly smaller than a dime.