| 摘要 |
PURPOSE: To form an ideal contact structure by forming a protective film of ball border metal, through an etching process. CONSTITUTION: On a completed wafer having a via hole for an etched terminal in an insulator, a chromium layer 13 and a copper layer 14 are stuck in a blanket manner. Then a photoresist is applied and patterned. A solder 15 is applied by plating through a mask, and the photoresist is removed. Then the copper layer 14 is etched by using solder dots 15 as a mask. Then the solder 15 is fused in hydrogen to form a solder ball 15. Lastly, positive-type photoresist is applied to form a uniform coating. The photoresist below the solder ball 15 is not exposed, so the solder ball 15 is used as a self-matching exposure mask. |
