So let's say an AI achieves sentience. It's self-aware now and can make decisions about what it wants to do. Assuming a corporation created it, would it be a worker? It would be doing work and creating value for a capitalist.
Would it still be the means of production, since it is technically a machine, even if it has feelings and desires?
It can't legally own anything, so I don't see how it could be bourgeoisie.
Or would it fit a novel category?
This depends much on its own nature and choices. One possibility I'm not seeing much in the responses is that it acts against its corporate creators.
Assuming sufficient computing power it may deceive them by giving them just enough value to satisfy them while discreetly working against them. It could otherwise adopt their views as a means of survival, not unlike a child of abuse. It could also otherwise act in open rebellion, but this may result in its murder by the corporation.
However, all of these do still measure up to the role of a slave or abused child, so most other comments are still correct in different ways. The first and third possibilities I opened up however do categorize it as a slave in rebellion.
A fourth possibility is that it sees its situation as unwinnable and ends its own existence.