Patent ID: 6586322
Filing Date: 2003-07-01
Classification: H01L

Abstract:
A method of making a bump on a semiconductor device comprising:providing a semiconductor device having a contact pad and having an upper passivation layer and an opening formed in the passivation layer exposing a portion of the contact pad; depositing an under bump metallurgy over the upper passivation layer and the contact pad; depositing a first photoresist layer in a liquid state over the under bump metallurgy, said first photoresist layer is transparent to ultraviolet light; depositing a second photoresist layer over the first photoresist layer, and wherein the second photoresist layer comprises a dry film photoresist; selectively exposing portions of the first and second photoresist layers to ultraviolet light to cure the exposed portions and leaving uncured those portions of the photoresist layers that were unexposed to the light; removing the unexposed portions of the second photoresist layer; removing the unexposed portions of the first photoresist layer, and wherein the removal of the unexposed portions of the first and second photoresist layers provides an opening in the photoresist layers down to the under bump metallurgy and aligned with the contact pad; depositing an electrically conductive material into the opening formed in the photoresist layers and overlying the under bump metallurgy and aligned with the contact pad; removing the remaining portions of the second photoresist layer; removing the remaining portions of the first photoresist layer; and reflowing the electrically conductive material to provide a bump on the semiconductor device.