The Holy Catholic Church teaches that no one or nothing made God. His existence has no beginning and no end.  God always was and always will be.  There never was any time when God was not, neither will there be any time when He will not be.  If the existence of god began at a particular time, then it will mean that 'he' is a creature' that had to have been made by some 'being'.  But God was not made.  He never came into being nor will He ever cease being. There is a 'being' who is the source of every other being, and who 'himself' did not originate from any other being because 'he' has in himself the fullness of being.  He IS God.

Ref CCC. 213, Exodus 3: 13-14

Taken From The Compendium  - Catechism Of The Catholic Church