| 摘要 |
PROBLEM TO BE SOLVED: To easily form a solder bump by completely covering the whole exposed surface of a first metal layer making ohmic junction with a silicon semiconductor with a second metal layer whose corrosion resistance against organic acid is higher and solder wettability is higher than the metal of the first metal layer. SOLUTION: The first metal layer 2 is formed on the face of the silicon semiconductor element 1 in prescribed thickness. Then, the second metal layer 3 is stacked in prescribed thickness so that the whole exposed surface of the first metal layer 2 is covered with it. Metal making ohmic junction with the silicon substrate is selected as metal used for the first metal layer 2 in electrode structure. Higher corrosion resistance against organic acid than the metal of the first metal layer 2, satisfactory solder wettability and satisfactory adhesive strength with the silicon semiconductor 1 and the first metal layer 2 are required as the selection reference of metal used for the second metal layer 3. Thus, the thickness of solder is easily controlled, bonding height can be taken to be large and heat resistance can be improved. |
