SEMICONDUCTOR DEVICE HAVING PAD STRUCTURE WITH STRESS BUFFER LAYER

摘要

PURPOSE: A semiconductor device with a pad structure which a stress buffer layer is provided to buffer physical stress in a WLCSP and a related flip chip package without side effects on device performance. CONSTITUTION: A metal pad is formed on a semiconductor substrate(101). Major parts of the metal pad are exposed through an opening. A passivation layer includes the opening(102). A ring shaped stress buffer layer has an opening which exposes a portion of the major parts of the metal pad. The ring shaped stress layer is formed on the passivation layer(103). An under bump metallization layer is formed on exposed parts of the metal pad and a stress buffer layer(104). A metal bump is electrically connected to the metal pad on the under bump metallization layer(105).