The question “Who made God” is commonly used to argue against the existence of the sort of god traditionally believed in by Christians, Jews, Muslims, and many other monotheists. Strictly speaking, this isn’t an independent argument because it is not offered on its own. Instead, it is used as a rebuttal to the claim that our universe is too complex and intricate not to have been designed.
Related: Richard Dawkins and the "Who Made God?" Question