| 摘要 |
<P>PROBLEM TO BE SOLVED: To make contact resistance between a pad electrode of a power device and a UBM (Under Bump Metal) be the same value as in the case of forming the UBM by plating though forming the UBM by spattering. <P>SOLUTION: An impurity ion is ion implanted into a surface layer of a pad electrode 9a exposed on a protection film 11. Accordingly, a UBM contact layer 10 including an alumina (Al<SB POS="POST">2</SB>O<SB POS="POST">3</SB>) film damaged by ion implantation and an amorphous aluminum (Al) film in a lower layer is formed in the surface layer of the pad electrode 9a. Subsequently, a titanium (Ti) film is sputtered and a nickel (Ni) film is spattered on the titanium film. Because the damaged alumina (Al<SB POS="POST">2</SB>O<SB POS="POST">3</SB>) film on the surface layer of the pad electrode 9a is subject to enhanced reduction by the sufficient amount of titanium (Ti) film, aluminum (Al) included in the pad electrode 9a and UBM 12 form a favorable ohmic contact. <P>COPYRIGHT: (C)2012,JPO&INPIT |
