| abstract |
A method of forming an integrated circuit device includes forming an under-bump metallurgy (UBM) layer overlying a semiconductor substrate. Next, a first photoresist film is formed on the UBM layer where the first photoresist film has a first photosensitivity and a first thickness. Additionally, the method includes forming a second photoresist film on the first photoresist film. Next, the method includes performing an exposure process on the second photoresist film and the first photoresist film. The method further includes removing an exposed portion of the second photoresist film to form a first opening. The method further also includes removing an exposed portion of the first photoresist film to expose a portion of the UBM layer. Furthermore, the method includes forming a copper layer in the first opening. The method also includes removing the second photoresist film and the first photoresist film where the copper layer forms a copper post. |