Wow. imagine starting off with this and then following it up the way you did.
No, Omnivision did. There's also no such thing as a "consumer" BSI. it's a BSI sensor developed using your patent rights.
If anyone "invented" it, I'd place my bets on Eric Fossum.
They held patents and released it first in the market - invented doesn't have any meaning here. Canon, OmniVision, Samsung all had patents in this space.
You know this is illegal, right? Canon has thousands of patents on sensor technology. They don't have to "copy" anyone's and they couldn't anyways how sony did their sensors is literally protected by their IP rights.
You really are out of your league here.
Pot meet kettle.
The methods and means of making stacked sensors for small sensors is 100000% different than it is for large sensors.
there's
a) heat.
b) noise
c) timing lag
Then you have the fact that most smartphone sensors are mounted to the phone and not on floating IBIS platform, adds in even more complexity. Also things such as localized heat sources, etc don't happen on smaller sensors.
All these a small sensor doesn't even have to consider - so yeah.. Physics and stuff.
This is even more an issue with the logic aspect because - usually as design rules shrink so does the die, but in the case of a sensor, the die cannot shrink - which then adds more resistance, and then heat, etc.
Then there's the fact that outside of readout speed, a stacked sensor really doesn't help that much when your pixel size is large. You stack a sensor to optimize the size of the pixel wells, but you already do that anyway with BSI. Stacked only allows you to optimize speed.
Canon unlike Sony - decides to release something when they feel it's good and serves the intended purpose. They don't usually take 3 generations to get it right.
Also - you do know that Canon commercialized a full frame global shutter sensor around 3 years ago - they just don't think it's worthy of being in a 1 series body. Again, unlike Sony.