Methods of Forming Through-Substrate Vias

Abstract

A method of forming through-substrate vias includes separately electrodepositing copper and at least one element other than copper to fill remaining volume of through-substrate via openings formed within a substrate. The electrodeposited copper and the at least one other element are annealed to form an alloy of the copper and the at least one other element which is used in forming conductive through-substrate via structures that include the alloy.

1 . A method of forming through-substrate vias, comprising:
 separately electrodepositing copper and at least one element other than copper to fill remaining volume of through-substrate via openings formed within a substrate; and   annealing the electrodeposited copper and the at least one other element to form an alloy of the copper and the at least one other element, and forming conductive through-substrate via structures comprising the alloy.   
     
     
         2 . The method of  claim 1  wherein the electrodepositings are of copper and only one other element. 
     
     
         3 . The method of  claim 2  wherein the alloy consists essentially of either copper and zinc or copper and tin. 
     
     
         4 . The method of  claim 3  wherein the alloy consists essentially of copper and zinc, with the zinc being at from about 0.5% to 25% by weight in the alloy. 
     
     
         5 . The method of  claim 2  comprising a total of two electrodepostings. 
     
     
         6 . The method of  claim 2  comprising a total of more than two electrodepostings. 
     
     
         7 . The method of  claim 6  comprising a total of more than three electrodepostings. 
     
     
         8 . The method of  claim 7  comprising alternating every copper electrodepositing with electrodepositing of the other element. 
     
     
         9 . The method of  claim 1  wherein the electrodepositings are of copper and multiple elements other than copper. 
     
     
         10 . The method of  claim 9  comprising a total of three electrodepositings. 
     
     
         11 . The method of  claim 9  comprising a total of more than three electrodepositings. 
     
     
         12 . The method of  claim 1  comprising conducting the annealing in an inert atmosphere. 
     
     
         13 . The method of  claim 1  comprising conducting the annealing at from about 150° C. to 450° C. for from about 0.5 hour to about 3 hours. 
     
     
         14 . The method of  claim 1  wherein the alloy is homogenous. 
     
     
         15 . The method of  claim 1  wherein all conductive material within the through-substrate via openings consists essentially of the alloy, but for any conductive copper diffusion barrier material that might be present radially outward of said alloy. 
     
     
         16 . The method of  claim 15  wherein the alloy is homogenous. 
     
     
         17 . A method of forming through-substrate vias, comprising:
 forming through-substrate via openings partially through a substrate from a first side of the substrate;   lining sidewalls of the through-substrate via openings with dielectric;   lining conductive seed material laterally over the dielectric within the through-substrate via openings;   separately electrodepositing copper and at least one element other than copper to fill remaining volume of the through-substrate via openings;   annealing the electrodeposited copper and the at least one other element to form an alloy of the copper and the at least one other element; and   after the annealing, removing substrate material from a second side of the substrate opposite the first side to expose and project conductive through-substrate via structures comprising the alloy from the second side of the substrate.   
     
     
         18 . The method of  claim 17  wherein the seed material comprises copper. 
     
     
         19 . The method of  claim 17  comprising lining diffusion barrier material over the dielectric within the through-substrate via openings before providing the conductive seed material within the through-substrate via openings. 
     
     
         20 . The method of  claim 17  wherein the first of the separate electrodepositings is of copper. 
     
     
         21 . The method of  claim 17  wherein the first of the separate electrodepositings is of an element other than copper. 
     
     
         22 . The method of  claim 17  wherein the last of the separate electrodepositings is of copper. 
     
     
         23 . The method of  claim 17  wherein the last of the separate electrodepositings is of an element other than copper. 
     
     
         24 . The method of  claim 17  wherein the at least one other element comprises at least one of tin or zinc. 
     
     
         25 . A method of forming through-substrate vias, comprising:
 electrodepositing one of copper or one element other than copper to form a metal lining within respective through-substrate via openings formed within a substrate, the metal lining forming an outwardly open void within the respective through-substrate via openings;   electrodepositing the other of the copper or one element to fill the voids; and   annealing the electrodeposited copper and one element to form an alloy of the copper and one element, and forming conductive through-substrate via structures comprising the alloy.   
     
     
         26 . The method of  claim 25  wherein copper is electrodeposited first and the one element is electrodeposited to fill the voids. 
     
     
         27 . The method of  claim 25  wherein the one element is electrodeposited first and copper is electrodeposited to fill the voids. 
     
     
         28 . The method of  claim 25  wherein the outwardly open voids and the filled voids are centered radially within the through-substrate via openings. 
     
     
         29 . The method of  claim 25  comprising electrodepositing the copper to be laterally thicker than the electrodeposited one element. 
     
     
         30 . A method of forming through-substrate vias, comprising:
 electrodepositing one of copper or an element other than copper to form a first metal lining within respective through-substrate via openings formed within a substrate, the first metal lining being formed laterally inward of and directly against a conductive seed material formed over sidewalls of the respective through-substrate via openings, the first metal lining forming an outwardly open first void within the respective through-substrate via openings;   electrodepositing the other of the copper or other element to form a second metal lining within the respective through-substrate via openings, the second metal lining being formed laterally inward of and directly against the first metal lining, the second metal lining forming an outwardly open second void within the respective through-substrate via openings;   filling the second voids with electrodeposited metal; and   annealing the substrate to form an alloy containing at least copper and the other element, and forming conductive through-substrate via structures comprising the alloy.   
     
     
         31 . The method of  claim 30  wherein the alloy consists essentially of copper and said other element. 
     
     
         32 . The method of  claim 30  wherein filling the second voids comprises:
 electrodepositing the one of the copper or other element to form a third metal lining within the respective through-substrate via openings, the third metal lining being formed laterally inward of and directly against the second metal lining, the third metal lining forming an outwardly open third void within the respective through-substrate via openings; and 
 filling the third voids with electrodeposited metal. 
 
     
     
         33 . The method of  claim 32  wherein the alloy consists essentially of copper and said other element. 
     
     
         34 . The method of  claim 32  wherein filling the third voids comprises:
 electrodepositing the other of the copper or other element to form a fourth metal lining within the respective through-substrate via openings, the fourth metal lining being formed laterally inward of and directly against the third metal lining, the fourth metal lining forming an outwardly open fourth void within the respective through-substrate via openings; and 
 filling the fourth voids with electrodeposited metal. 
 
     
     
         35 . The method of  claim 34  wherein the alloy consists essentially of copper and said other element.