Can you explain the ontology of the wave function?
Well that depends on whether the wave function is something real in itself, or just a mathematical device which explains the behavior of things which are real. Does a mere “description of reality” have an ontological existence and essence on its own? The metaphysicians are welcome to this one, since whatever answer they give is not going to impinge in any way on the fact that the wavefunction accurately predicts the behavior (at least in a probabilistic sense), and physics is not going to be able to answer basic questions about ontology anyway.
Or perhaps in scientific terms what is producing this wave function and what it is comprised of?
That question doesn’t make sense if the wave function is just a descriptive mathematical function, so we’ll have to assume here that the wave function is a real ontological entity. Science can’t give the complete answer; here’s what it can say.
We can say that the wave function is comprised of everything that is real. But we can’t show exactly what those things are, things that are (or are thought to be) ontological objects (such as water molecules), just by looking at the form of the function itself. They don’t completely factorize, especially if they’re bonding with other water molecules. But, once you know what these ontological entities are by some other means, then the entire wave function is comprised of them, whatever they are.
We can say that nothing physical produced the wave function (which evolved from an initial state, at the Big Bang), if Big Bang cosmology is correct.