Looks like someone from Young Indy helped write AOTC, but judging by the dialogue I suspect that most of it came from Lucas.
Since AOTC has worse dialogue than TPM and ROTS, the assumption could be opposite.
Attack of the Clones has the most cliché dialogue of any movie in the Star Wars saga, but the dialogue in The Phantom Menace is even worse. Jar Jar Binks is in almost every scene, the gungans speak in broken English, the battle droids repeatedly say, “Roger, Roger,” the Neimodians speak in poor imitations of Asian accents, the characters constantly mention treaties, and the nine-year-old Anakin asks Padmé, “Are you an angel?”
So the dialogue in Attack of the Clones is still better than The Phantom Menace.
I will admit that other than a few failed attempts at comic relief, the dialogue in The Force Awakens was actually surpisingly good.