I saw this clickbait article once about how china was making laser propelled submarines, and the 3D stacking logic chips kind of sounds about as outlandish.

Looking into it, they are "folding" a logic chip to have shorter paths with their SRAMs, which is the main application of 3D integration these days, chucking memory (low-power) above high power logic die.

stacking logic chips is hard because they have to dissipate a lot of power, and stacking them multiplies your power density (which is already very high for the logic die, generally) by the number dies you stack~effectively. Most of the progress on these sorts of things have just been stacking layer on layer of memory on a single logic die.

It looks like they are folding other components other than memory onto the logic die which I haven't seen before, but this isn't cold fusion and even intel has thrusts doing this type of 3D integration.