The image sensor industry is incestuous. Indeed, a lot of the tech industry centered around semiconductors is incestuous.
Recently we've had another round of misinformation articles (and clickbait headlines) centered around naive understanding and sometimes just outright conspiracy theories regarding image sensors. I'm not going to point to those articles, as they don't deserve pointing to.
The image sensor industry is smaller and more interwoven than people think. First, there are really only three makers of the equipment that is used to make most semiconductors (ASML, Canon, and Nikon). Second, there are only a handful of Universities around the world that have top-level semiconductor programs. Third, the image sensor community has long met in tech conferences where they disclose and discuss new ideas and understandings in detail. And finally, there's a high degree of licensing that goes on behind the scenes (once in awhile you see that clearly disclosed, as in Sony's licensing of Aptina's dual gain technology, but not always). Finally, the billion dollar+ investments to actually build out a fully functional fab to produce a semiconductor (image sensor) means that not a lot of those exist.
The intersection of all those things makes for a very small world in which little isn't known to one another, and everything merges to the center over time. Moreover, you see people transfer around a bit, too. But the bottom line is that any imaging sensor fab was probably installed by Canon or Nikon (ASML has been concentrating on semiconductors that require process size diminution, such as CPUs). Those fabs are owned by Canon or Sony or typically two or three other parties. The people trying to get mass production image sensors of APS-C sizes or larger are basically Canon, Fujifilm, Nikon, Panasonic, and Sony. And the people doing the low-level transistor specification, layout, and taping may be one of a few third party firms with the proper tools for the fab machinery, used under the direction of those last five companies. (There is one small side bet: Sigma. For the Foveon sensor, Sigma is using a small for-hire fab in Roseville, CA.)
If you and I were to start a new camera company, we'd have three basic choices: (1) buy an off-the-shelf sensor; (2) take an off-the-shelf sensor and make low-level modifications to things like timing and gains and have it re-taped by someone for production; or (3) create our own sensor from scratch. The words "design" and "make" are nebulous for #2 and #3; only for #1 would there be a clear designer and maker.
Interestingly enough, Canon, Nikon, and Sony—Sony Imaging, not Sony Semiconductor—make all three sensor choices in varying degrees and have done so at various times (with Canon, they've bought sensors for their smaller cameras, up through 1"). It's the classic "buy versus make" conundrum in a nutshell. Sometimes it's just better to buy and use your downstream goodies to differentiate, sometimes it's better to make and start a new competition point on your own.
I think we can be somewhat clear, therefore, only about one company for ILC today:
- Canon — makes their own fab equipment, has their own sensor designers, does little outside licensing, and runs their own fab. I think we can safely say "designed and made by Canon" for all the DSLR/mirrorless sensors Canon is using.
By contrast:
- Fujifilm — currently only specifies toppings to the sensors; may still have some sensor designers (was very active pre 2000); typically licenses Sony Semiconductor sensors that are made by Sony. There's no clear designation you can make about the Fujifilm sensors. They're designed and made by Sony Semiconductor, but with color filter and microlens toppings that Fujifilm designs.
- Nikon — makes fab equipment for some of the sensor makers; has their own sensor designers; does a lot of outside licensing; but never runs their own fab. Thus "designed by Nikon" is the only thing they claim when they're not using an off-the-shelf sensor, and sometimes that word means a lot, sometimes it means only a little.
- Panasonic — I can't speak to Panasonic any more, as I lost contact with engineers that would know exactly where they are today.
- Sigma — has their own sensor designers, farms all the fabbing out to another firm. Definitely a "designed by Sigma" label would be appropriate for all Foveon sensors. For the fp, Sigma appears to use an off-the-shelf Sony Semiconductor sensor.
- Sony Imaging — (note the distinction on these last two entries) doesn't have fab equipment (directly); has their own sensor designers; runs in close conjunction with their sibling company (below) who fabs their sensors. It's not a stretch to say "designed and made by Sony" for all Sony cameras, though which aspect of Sony does the first part can vary, and there is sometimes IP that came from elsewhere in the "designed by" part.
- Sony Semiconductor — buys fab equipment (I'm not sure about 2021, but last time I was able to verify, it was from Nikon); has their own designers; is one of the most active at licensing intellectual property from other companies (though a lot of this is not disclosed); runs their own fab. Sony Semi makes off-the-shelf sensors, but it will vary known designs to client specifications. Sony Semi will (sometimes; mostly an artifact of buying the Renasas and Toshiba fabs) fab something that was designed elsewhere.
Personally, I don't care much about sensor origin just as I don't know care a lot about CPU origin or RAM origin or NAND origin. It's really what you do with the part that is important.