Conductive structure for a semiconductor integrated circuit and method for forming the same

Abstract

A conductive structure for a semiconductor integrated circuit and method for forming the conductive structure are provided. The semiconductor integrated circuit has a pad and a passivation layer partially covering the pad to define a first opening portion having a first lateral size. The conductive structure electrically connects to the pad via the first opening portion. The conductive structure comprises a support layer defining a second opening portion. A conductor is formed in the second opening portion to serve as a bump having a planar top surface.

1 . A method for forming a conductive structure on a semiconductor integrated circuit which has a pad and a passivation layer partially overlapping the pad to define a first opening portion having a first lateral dimension, the method comprising the steps of:
 (a) forming a second opening portion having a second lateral dimension by forming a supporting layer, wherein the second lateral dimension is substantially not greater than the first lateral dimension; and   (b) electrically connecting a conductor formed in the second opening portion to the pad through the first opening portion.   
     
     
         2 . The method as claimed in  claim 1 , further comprising the step of forming a conductive layer having a central portion being located at the first opening portion before the step (a). 
     
     
         3 . The method as claimed in  claim 2 , wherein the step of forming the conductive layer comprises forming the conductive layer which has a periphery portion being at least partially formed between the supporting layer and the passivation layer. 
     
     
         4 . The method as claimed in  claim 1 , when in the step (b), the conductor is formed to have a fourth vertical dimension which is substantially not smaller than a third dimension of the supporting layer.