Conductive compositions and processes for use in the manufacture of semiconductor devices

Abstract

The present invention is directed to a thick film conductive composition comprising: (a) electrically conductive silver powder; (b) zinc-containing additive; (c) glass frit wherein said glass frit is lead-free; dispersed in (d) organic medium. The present invention is further directed to an electrode formed from the composition above wherein said composition has been fired to remove the organic vehicle and sinter said glass particles. Still further, the invention is directed to a method of manufacturing a semiconductor device from a structural element composed of a semiconductor having a p-n junction and an insulating film formed on a main surface of the semiconductor comprising the steps of (a) applying onto said insulating film the thick film composition detailed above; and (b) firing said semiconductor, insulating film and thick film composition to form an electrode. Additionally, the present invention is directed to a semiconductor device formed by the method detailed above and a semiconductor device formed from the thick film conductive composition detailed above.

1 . A composition comprising:
 (a) a thick film composition comprising:
 a) an electrically conductive silver powder; 
 b) one or more glass frits wherein said glass frits are lead-free, and wherein the one or more glass frits comprise Bi 2 O 3  28-85, Al 2 O 3  0-4, Si 2 O 3  0.1-8: dispersed in 
 c) an organic medium; 
   (b) an insulating film
 wherein the thick film composition is formed on the insulating film, and 
 wherein, upon firing, the insulating film is penetrated by components of the thick film composition and the organic medium is removed. 
   
     
     
         2 . The glass frit of  claim 1  comprising, based on weight percent total glass composition:
 SiO 2  0.1-8 
 Al 2 O 3  0-4 
 B 2 O 3  8-25 
 CaO 0-1 
 ZnO 0-42 
 Na 2 O 0-4 
 Li 2 O 0-3.5 
 Bi 2 O 3  28-85 
 Ag 2 O 0-3 
 CeO 2  0-4.5 
 SnO 2  0-3.5, and BiF 3  0-15. 
 
     
     
         3 . The thick film composition of claim further comprising an additional metal/metal oxide additive selected from (a) a metal wherein said metal is selected from Zn, Gd, Ce, Zr, Ti, Mn, Sn, Ru, Co, Fe, Cu, and Cr: (b) a metal oxide of one or
 more of the metals selected from Gd, Ce, Zr, Ti, Mn, Sn, Ru, Co, Fe, Cu, and Cr: (c) any compounds that can generate the metal oxides of (b) upon firing; and (d) mixtures thereof.   
     
     
         4 . An electrode formed from the composition of  claim 1  wherein said composition has been fired to remove the organic vehicle and sinter said glass particles. 
     
     
         5 . The composition of  claim 1 , wherein the insulating film comprises one or more components selected from the group consisting of: titanium oxide, silicon nitride, SiN x :H, silicon oxide, and silicon oxide/titanium oxide. 
     
     
         6 . The composition of  claim 1 , wherein the composition further comprises a semiconductor substrate, and wherein the insulating film is formed on the semiconductor substrate. 
     
     
         7 . The composition of  claim 6 , wherein the composition further comprises a back electrode. 
     
     
         8 . A semiconductor device, comprising the composition of  claim 6 , wherein the composition has been fired, wherein the firing removes the organic vehicle and sinters the silver and glass frits, and wherein the conductive silver and frit mixture penetrate the insulating film. 
     
     
         9 . The composition of  claim 1 , wherein the insulating film is an anti-reflection coating. 
     
     
         10 . A thick film conductive composition comprising:
 (a) electrically conductive silver powder;   (b) Cr-containing additive, wherein the Cr-containing additive is selected from: (a) Cr; (b) a metal oxide of Cr; (c) any compounds that can generate the metal oxides of Cr upon firing; and (d) mixtures thereof;   (c) one or more glass frits; dispersed in   (d) organic medium.   
     
     
         11 . The composition of  claim 10 , wherein the one or more of the glass frits are lead-free. 
     
     
         12 . A method of manufacturing a semiconductor device from a structural element composed of a semiconductor having a p-n junction and an insulating film formed on a main surface of the semiconductor comprising the steps of
 (a) applying onto said insulating film a thick film composition comprising:
 a) electrically conductive silver powder; 
 b) Cr-containing additive, wherein the Cr-containing additive is selected from: (a) Cr; (b) a metal oxide of Cr; (c) any compounds that can generate the metal oxides of Cr upon firing; and (d) mixtures thereof; 
 c) one or more glass frits; dispersed in 
 d) organic medium; 
 and (b) firing said semiconductor, insulating film and thick film composition to form an electrode. 
   
     
     
         13 . The method of  claim 12 , wherein the insulating film is selected from the group comprising silicon nitride film, titanium oxide film, SiN x :H film, silicon oxide film and a silicon oxide/titanium oxide film. 
     
     
         14 . A semiconductor device formed by the method of  claim 12 . 
     
     
         15 . A semiconductor device formed from the composition comprising:
 a) electrically conductive saver powder;   b) Cr-containing additive, wherein the Cr-containing additive is selected from: (a) Cr; (b) a metal oxide of Cr; (c) any compounds that can generate the metal oxides of Cr upon firing; and (d) mixtures thereof   c) one or more glass frits; dispersed in   d) organic medium
 wherein said composition has been processed to remove said organic medium and sinter said glass frit and silver powder.