| 摘要 |
PURPOSE:To prevent an element from deteriorating its electrical characteristics at high temperatures, by making a bonding promotion layer smaller than a lower barrier metal, and leaving its peripheral edge far from an inner edge of insulation film defining a contact window. CONSTITUTION:A P type region 5 is provided at the center of an N type Si substrate 4 to have a shallow P-N junction. The substrate 4 has a cathode 13 on its lower surface and an anode 9 on its upper surface. The anode 9 is formed on a contact window region 7 where a passivation film 14 covering the surface of the substrate 4 is removed partially. It consists of a barrier metal 10 of titanium, a bonding promotion layer 11 of Pd formed thereupon, and a bump electrode 12 of silver formed thereupon, making a triple layer structure. The layer 11 is smaller than the metal 10, and its peripheral edge is far from an inner edge of insulation film 8 on the region 5. Namely, this prevents the Pd layer fast in alloying with Si from existing on the upper part of P type region 5 corresponding to the inner peripheral edge of insulation film 8 high in thermal stress. |
