Does Nikon design their own sensors?
According to this post by Thom Hogan:
Nikon has had sensor development teams very active since at least 1988. They are more than capable of designing their own sensors, and have been for years. If you follow the scholarly and academic papers with sensors, you’d know that Nikon has been at the center of a lot of different technologies in the area.
I’ll repeat what I’ve written elsewhere: it is HIGHLY unlikely that the D3 / D700 sensor was produced by Sony. It doesn’t have Sony-style markings on it, for one thing (Sony wouldn’t have changed their sensor line equipment for marking chips for a low volume run of D3/D700 sensors). Nikon says the D3/D700 is their design. I believe them (based upon both public and non-public information). Nikon won’t say who actually manufactured them, though there are really only a handful of fabs that use that style of marking, so one could make an educated guess, I suppose.
More:
Those of us with long memories recall that Sony didn’t want to produce an APS sensor at all, and Nikon was the one that convinced them to, actually dictating a binned design that Sony hadn’t done before.