It's a bit fuzzier. The popular model prior to Childe was Lewis Morgan's three stage Savagery->Barbarism->Civilization model. When Childe published his famous paper [1] laying out the criteria, he acknowledged Morgan (though I'm not sure it's cited in the paper itself) and was intentionally providing standardized criteria to recognize the last stage. Childe himself preferred the terminology of "city" and later archaeologists adopted the phrase "state", but really these are all the same broad concept with slightly different connotations.

But aside from a few exceptions (people at USYD, Michael Smith), Childe's definitions are increasingly disagreeable to archaeologists. Most of the newer generations, myself included, find anti-evolutionist arguments significantly more persuasive and even those that don't aren't big fans of the original formulation of Childe's ideas.

[1] http://www.jstor.org/stable/40102108