Manufacturing method for semiconductor devices

Abstract

A manufacturing method for semiconductor devices includes the steps of forming an Ni/Au film that includes an Ni film and an Au film formed over the Ni film over a wiring that is coupled to each of a plurality of electrode pads formed over a principal surface of a semiconductor wafer and arranges each of the electrode pads at a different position, grinding a back surface of the semiconductor wafer, performing reduction treatment on a surface of the Ni/Au film, and forming a solder bump over the Ni/Au film. In the reduction treatment, respective processes of flux application, reflow soldering and cleaning are performed and the solder bump is bonded to the Ni/Au film after the reduction treatment has been completed. Thereby, bonding reliability in flip chip bonding of a semiconductor device is improved.

1 - 12 . (canceled) 
     
     
         13 . A method for manufacturing a semiconductor device, comprising:
 (a) providing a semiconductor substrate having a multilayer wiring and an electrode pad formed at an uppermost layer of the multilayer wiring;   (b) after (a), forming a rewiring electrically coupled to the electrode pad;   (c) after (b), forming a first metal film over the rewiring;   (d) after (c), forming a second metal film over the first metal film;   (e) after (d), performing a reduction treatment on a surface of the second metal film; and   (f) after (e), forming a bump over the second metal film.   
     
     
         14 . The method for manufacturing a semiconductor device according to  claim 13 , wherein the first metal film is a Ni film. 
     
     
         15 . The method for manufacturing a semiconductor device according to  claim 14 , wherein the second metal film is an Au film. 
     
     
         16 . The method for manufacturing a semiconductor device according to  claim 13 , wherein the bump is an Sn bump. 
     
     
         17 . The method for manufacturing a semiconductor device according to  claim 14 , wherein (e) comprises:
 (e1) applying a flux constituent material;   (e2) after (e1), performing reflow soldering; and   (e3) after (e2), performing cleaning.   
     
     
         18 . The method for manufacturing a semiconductor device according to  claim 17 , wherein the flux constituent material is a same material as that of a flux material that is applied to the second metal film after the reduction treatment has been performed and before the bump is formed. 
     
     
         19 . The method for manufacturing a semiconductor device according to  claim 18 , wherein before (f), a back surface that is opposite to a principal surface of the semiconductor substrate is ground. 
     
     
         20 . The method for manufacturing a semiconductor device according to  claim 13 , further comprising:
 grinding a back surface of the semiconductor substrate, the back surface being opposite to a principal surface of the semiconductor substrate, the multilayer wiring being formed over the principal surface.   
     
     
         21 . The method for manufacturing a semiconductor device according to  claim 13 , wherein the reduction treatment comprises acid cleaning. 
     
     
         22 . The method for manufacturing a semiconductor device according to  claim 13 , wherein the forming the second metal film in (d) includes electroless plating. 
     
     
         23 . A method for manufacturing a semiconductor device, comprising:
 forming a first metal film over a rewiring on a semiconductor substrate, the semiconductor substrate having a multilayer wiring and an electrode pad formed at an upper layer of the multilayer wiring, the rewiring being electrically connected to the electrode pad;   forming a second metal film over the first metal film;   performing a reduction treatment on a surface of the second metal film; and   forming a bump over the second metal film after the reduction treatment.   
     
     
         24 . The method of  claim 23 , wherein the first metal film comprises Ni. 
     
     
         25 . The method of  claim 23 , wherein the second metal film comprises Au. 
     
     
         26 . The method of  claim 23 , wherein the bump comprises Sn. 
     
     
         27 . The method of  claim 23 , wherein the performing the reduction treatment comprises applying a flux constituent material followed by reflow soldering and cleaning.