Selective deposition of solder ball contacts

Abstract

Some embodiments of the invention include methods of forming solder ball contacts having dimensions of approximately 2.5 microns in diameter for use in C4-type connections. The methods form solder ball contacts using selective deposition of solder on metal contact pads of a device. The metal contact pads have exposed portions at the bottom of through holes. The through holes define the dimensions of the exposed portions of the metal contact pads, and serve to limit the dimensions of the resulting solder contact by limiting the area upon which deposition preferentially occurs. Subsequent reflow of the deposited solder forms a solder ball contact. Various devices, modules, systems and other apparatus utilize such methods of forming solder ball contacts.

1 . A semiconductor die comprising: 
 an integrated circuit supported by a substrate;    a metal pattern line coupled to the integrated circuit;    a metal contact pad coupled to the metal pattern line; and    a solder ball contact coupled to the metal contact pad, wherein the solder ball contact is formed by a method, the method including: 
 forming an insulating layer on the metal contact pad;  
 removing a portion of the insulating layer to expose a portion of the metal contact pad, thereby forming an exposed portion of the metal contact pad;  
 depositing solder on the exposed portion of the metal contact pad using a selective deposition, thereby forming a solder contact; and  
 annealing the solder contact to form the solder ball contact.  
   
   
   
       2 . The semiconductor die of  claim 1 , wherein the selective deposition includes immersion contact.  
   
   
       3 . The semiconductor die of  claim 1 , wherein the selective deposition includes electrolytic deposition.  
   
   
       4 . The semiconductor die of  claim 1 , wherein the selective deposition includes chemical vapor deposition.  
   
   
       5 . The semiconductor die of  claim 1 , wherein the solder includes at least one material selected from the group consisting of lead, tin and bismuth.  
   
   
       6 . The semiconductor die of  claim 1 , wherein the metal contact pad includes a stack of zirconium, nickel, copper, gold, and lead.  
   
   
       7 . The semiconductor die of  claim 1 , wherein the exposed portion of the metal contact pad has a diameter, wherein the diameter has a dimension ranging from a first dimension to a second dimension greater than the first dimension, and wherein the first dimension is approximately  2  microns.  
   
   
       8 . A semiconductor die comprising: 
 an integrated circuit supported by a substrate;    a metal pattern line coupled to the integrated circuit;    a metal contact pad coupled to the metal pattern line; and    a solder ball contact coupled to the metal contact pad, wherein the solder ball contact is formed by a method, the method including: 
 depositing an insulating layer on the metal contact pad;  
 removing a portion of the insulating layer to expose a portion of the metal contact pad, thereby forming an exposed portion of the metal contact pad;  
 immersing the substrate in molten solder to form a solder contact on the exposed portion of the metal contact pad; and  
 annealing the solder contact to form the solder ball contact.  
   
   
   
       9 . The semiconductor die of  claim 8 , wherein the molten solder includes at least one material selected from the group consisting of lead, tin and bismuth.  
   
   
       10 . A semiconductor die comprising: 
 an integrated circuit supported by a substrate;    a metal pattern line coupled to the integrated circuit;    a metal contact pad coupled to the metal pattern line; and    a solder ball contact coupled to the metal contact pad, wherein the solder ball contact is formed by a method, the method including: 
 forming an insulating layer on the metal contact pad;  
 removing a portion of the insulating layer to expose a portion of the metal contact pad, thereby forming an exposed portion of the metal contact pad;  
 adsorbing reactants on the exposed portion of the metal contact pad;  
 reacting the reactants on the exposed portion of the metal contact pad, thereby forming a solder contact; and  
 annealing the solder contact to form the solder ball contact.  
   
   
   
       11 . A semiconductor die comprising: 
 an integrated circuit supported by a substrate;    a metal pattern line coupled to the integrated circuit;    a metal contact pad coupled to the metal pattern line; and    a solder ball contact coupled to the metal contact pad, wherein the solder ball contact is formed by a method, the method including: 
 forming an insulating layer on the metal contact pad;  
 forming a resist layer on the insulating layer;  
 patterning the resist layer to define a future exposed portion of the metal contact pad;  
 removing a portion of the insulating layer to expose a portion of the metal contact pad, thereby forming the exposed portion of the metal contact pad;  
 electrolytically depositing solder on the exposed portion of the metal contact pad, thereby forming a solder contact;  
 removing the resist layer, thereby exposing the solder contact above a surface of the insulating layer; and  
 annealing the solder contact to form the solder ball contact.  
   
   
   
       12 . The semiconductor die of  claim 1   1 , wherein the solder comprises at least one material selected from the group consisting of lead, tin and bismuth.  
   
   
       13 . An electronic system, comprising: 
 a processor; and    a circuit module having a plurality of leads coupled to the processor, and further having a semiconductor die coupled to the plurality of leads, wherein the semiconductor die comprises: 
 an integrated circuit supported by a substrate;  
 a metal pattern line coupled to the integrated circuit;  
 a metal contact pad coupled to the metal pattern line; and  
 a solder ball contact coupled to the metal contact pad, wherein the solder ball contact is formed by a method, the method including: 
 forming an insulating layer on the metal contact pad;  
 removing a portion of the insulating layer to expose a portion of the metal contact pad, thereby forming an exposed portion of the metal contact pad;  
 depositing solder on the exposed portion of the metal contact pad using a selective deposition, thereby forming a solder contact; and  
 annealing the solder contact to form the solder ball contact.  
 
   
   
   
       14 . The electronic system of  claim 13 , wherein the selective deposition includes immersion contact.  
   
   
       15 . The electronic system of  claim 13 , wherein the selective deposition includes electrolytic deposition.  
   
   
       16 . The electronic system of  claim 13 , wherein the selective deposition includes chemical vapor deposition.  
   
   
       17 . The electronic system of  claim 13 , wherein the solder includes at least one material selected from the group consisting of lead, tin and bismuth.  
   
   
       18 . The electronic system of  claim 13 , wherein the metal contact pad includes a stack of zirconium, nickel, copper, gold, and lead.  
   
   
       19 . The electronic system of  claim 13 , wherein the exposed portion of the metal contact pad has a diameter, wherein the diameter has a dimension ranging from a first dimension to a second dimension greater than the first dimension, and wherein the first dimension is approximately 2 microns.  
   
   
       20 . An electronic system, comprising: 
 a processor; and    a circuit module having a plurality of leads coupled to the processor, and further having a semiconductor die coupled to the plurality of leads, wherein the semiconductor die comprises: 
 an integrated circuit supported by a substrate;  
 a metal pattern line coupled to the integrated circuit;  
 a metal contact pad coupled to the metal pattern line; and  
 a solder ball contact coupled to the metal contact pad, wherein the solder ball contact is formed by a method, the method including: 
 depositing an insulating layer on the metal contact pad;  
 removing a portion of the insulating layer to expose a portion of the metal contact pad, thereby forming an exposed portion of the metal contact pad;  
 immersing the substrate in molten solder to form a solder contact on the exposed portion of the metal contact pad; and  
 annealing the solder contact to form the solder ball contact.  
 
   
   
   
       21 . The electronic system of  claim 20 , wherein the molten solder comprises at least one material selected from the group consisting of lead, tin and bismuth.  
   
   
       22 . An electronic system, comprising: 
 a processor; and    a circuit module having a plurality of leads coupled to the processor, and further having a semiconductor die coupled to the plurality of leads, wherein the semiconductor die comprises: 
 an integrated circuit supported by a substrate;  
 a metal pattern line coupled to the integrated circuit;  
 a metal contact pad coupled to the metal pattern line; and  
 a solder ball contact coupled to the metal contact pad, wherein the solder ball contact is formed by a method, the method including: 
 forming an insulating layer on the metal contact pad;  
 removing a portion of the insulating layer to expose a portion of the metal contact pad, thereby forming an exposed portion of the metal contact pad;  
 adsorbing reactants on the exposed portion of the metal contact pad;  
 reacting the reactants on the exposed portion of the metal contact pad, thereby forming a solder contact; and  
 annealing the solder contact to form the solder ball contact.  
 
   
   
   
       23 . An electronic system, comprising: 
 a processor; and    a circuit module having a plurality of leads coupled to the processor, and further having a semiconductor die coupled to the plurality of leads, wherein the semiconductor die comprises:    an integrated circuit supported by a substrate;    a metal pattern line coupled to the integrated circuit;    a metal contact pad coupled to the metal pattern line; and    a solder ball contact coupled to the metal contact pad, wherein the solder ball contact is formed by a method, the method including: 
 forming an insulating layer on the metal contact pad;  
 forming a resist layer on the insulating layer;  
 patterning the resist layer to define a future exposed portion of the metal contact pad;  
 removing a portion of the insulating layer to expose a portion of the metal contact pad, thereby forming the exposed portion of the metal contact pad;  
 electrolytically depositing solder on the exposed portion of the metal contact pad, thereby forming a solder contact;  
 removing the resist layer, thereby exposing the solder contact above a surface of the insulating layer; and  
 annealing the solder contact to form the solder ball contact.  
   
   
   
       24 . The electronic system of  claim 23 , wherein the solder comprises at least one material selected from the group consisting of lead, tin and bismuth.  
   
   
       25 . A memory module comprising: 
 a support;    a plurality of leads extending from the support;    a command link coupled to at least one of the plurality of leads;    a plurality of data links, wherein each data link is coupled to at least one of the plurality of leads; and    at least one memory device contained on the support and coupled to the command link, wherein the at least one memory device comprises: 
 an integrated circuit supported by a substrate;  
 a metal pattern line coupled to the integrated circuit;  
 a metal contact pad coupled to the metal pattern line; and  
 a solder ball contact coupled to the metal contact pad, wherein the solder ball contact is formed by a method, the method including: 
 forming an insulating layer on the metal contact pad;  
 removing a portion of the insulating layer to expose a portion of the metal contact pad, thereby forming an exposed portion of the metal contact pad;  
 depositing solder on the exposed portion of the metal contact pad using a selective deposition, thereby forming a solder contact; and  
 annealing the solder contact to form the solder ball contact.  
 
   
   
   
       26 . The memory module of  claim 25 , wherein the selective deposition includes immersion contact.  
   
   
       27 . The memory module of  claim 25 , wherein the selective deposition includes electrolytic deposition.  
   
   
       28 . The memory module of  claim 25 , wherein the selective deposition includes chemical vapor deposition.  
   
   
       29 . The memory module of  claim 25 , wherein the solder includes at least one material selected from the group consisting of lead, tin and bismuth.  
   
   
       30 . The memory module of  claim 25 , wherein the metal contact pad includes a stack of zirconium, nickel, copper, gold, and lead.  
   
   
       31 . The memory module of  claim 25 , wherein the exposed portion of the metal contact pad has a diameter, wherein the diameter has a dimension ranging from a first dimension to a second dimension greater than the first dimension, and wherein the first dimension is approximately 2 microns.  
   
   
       32 . A memory module comprising: 
 a support;    a plurality of leads extending from the support;    a command link coupled to at least one of the plurality of leads;    a plurality of data links, wherein each data link is coupled to at least one of the plurality of leads; and    at least one memory device contained on the support and coupled to the command link, wherein the at least one memory device comprises: 
 an integrated circuit supported by a substrate;  
 a metal pattern line coupled to the integrated circuit;  
 a metal contact pad coupled to the metal pattern line; and  
 a solder ball contact coupled to the metal contact pad, wherein the solder ball contact is formed by a method, the method including: 
 depositing an insulating layer on the metal contact pad;  
 removing a portion of the insulating layer to expose a portion of the metal contact pad, thereby forming an exposed portion of the metal contact pad;  
 immersing the substrate in molten solder to form a solder contact on the exposed portion of the metal contact pad; and  
 annealing the solder contact to form the solder ball contact.  
 
   
   
   
       33 . The memory module of  claim 32 , wherein the molten solder comprises at least one material selected from the group consisting of lead, tin and bismuth.  
   
   
       34 . A memory module comprising: 
 a support;    a plurality of leads extending from the support;    a command link coupled to at least one of the plurality of leads;    a plurality of data links, wherein each data link is coupled to at least one of the plurality of leads; and    at least one memory device contained on the support and coupled to the command link, wherein the at least one memory device comprises: 
 an integrated circuit supported by a substrate;  
 a metal pattern line coupled to the integrated circuit;  
 a metal contact pad coupled to the metal pattern line; and  
 a solder ball contact coupled to the metal contact pad, wherein the solder ball contact is formed by a method, the method including: 
 forming an insulating layer on the metal contact pad;  
 removing a portion of the insulating layer to expose a portion of the metal contact pad, thereby forming an exposed portion of the metal contact pad;  
 adsorbing reactants on the exposed portion of the metal contact pad;  
 reacting the reactants on the exposed portion of the metal contact pad, thereby forming a solder contact; and  
 annealing the solder contact to form the solder ball contact.  
 
   
   
   
       35 . A memory module comprising: 
 a support;    a plurality of leads extending from the support;    a command link coupled to at least one of the plurality of leads;    a plurality of data links, wherein each data link is coupled to at least one of the plurality of leads; and    at least one memory device contained on the support and coupled to the command link, wherein the at least one memory device comprises: 
 an integrated circuit supported by a substrate;  
 a metal pattern line coupled to the integrated circuit;  
 a metal contact pad coupled to the metal pattern line; and  
 a solder ball contact coupled to the metal contact pad, wherein the solder ball contact is formed by a method, the method including: 
 forming an insulating layer on the metal contact pad;  
 forming a resist layer on the insulating layer;  
 patterning the resist layer to define a future exposed portion of the metal contact pad;  
 removing a portion of the insulating layer to expose a portion of the metal contact pad, thereby forming the exposed portion of the metal contact pad;  
 electrolytically depositing solder on the exposed portion of the metal contact pad, thereby forming a solder contact;  
 removing the resist layer, thereby exposing the solder contact above a surface of the insulating layer; and  
 annealing the solder contact to form the solder ball contact.  
 
   
   
   
       36 . The memory module of  claim 35 , wherein the solder comprises at least one material selected from the group consisting of lead, tin and bismuth.  
   
   
       37 . A memory system comprising: 
 a controller;    a command link coupled to the controller;    a data link coupled to the controller; and    a memory device coupled to the command link and the data link, wherein the memory device comprises: 
 an integrated circuit supported by a substrate;  
 a metal pattern line coupled to the integrated circuit;  
 a metal contact pad coupled to the metal pattern line; and  
 a solder ball contact coupled to the metal contact pad, wherein the solder ball contact is formed by a method, the method including: 
 forming an insulating layer on the metal contact pad;  
 removing a portion of the insulating layer to expose a portion of the metal contact pad, thereby forming an exposed portion of the metal contact pad;  
 depositing solder on the exposed portion of the metal contact pad using a selective deposition, thereby forming a solder contact; and  
 annealing the solder contact to form the solder ball contact.  
 
   
   
   
       38 . The memory system of  claim 37 , wherein the selective deposition includes immersion contact.  
   
   
       39 . The memory system of  claim 37 , wherein the selective deposition includes electrolytic deposition.  
   
   
       40 . The memory system of  claim 37 , wherein the selective deposition includes chemical vapor deposition.  
   
   
       41 . The memory system of  claim 37 , wherein the solder includes at least one material selected from the group consisting of lead, tin and bismuth.  
   
   
       42 . The memory system of  claim 37 , wherein the metal contact pad includes a stack of zirconium, nickel, copper, gold, and lead.  
   
   
       43 . The memory system of  claim 37 , wherein the exposed portion of the metal contact pad has a diameter, wherein the diameter has a dimension ranging from a first dimension to a second dimension greater than the first dimension, and wherein the first dimension is approximately 2 microns.  
   
   
       44 . A memory system comprising: 
 a controller;    a command link coupled to the controller;    a data link coupled to the controller; and    a memory device coupled to the command link and the data link, wherein the memory device comprises: 
 an integrated circuit supported by a substrate;  
 a metal pattern line coupled to the integrated circuit;  
 a metal contact pad coupled to the metal pattern line; and  
 a solder ball contact coupled to the metal contact pad, wherein the solder ball contact is formed by a method, the method including: 
 depositing an insulating layer on the metal contact pad;  
 removing a portion of the insulating layer to expose a portion of the metal contact pad, thereby forming an exposed portion of the metal contact pad;  
 immersing the substrate in molten solder to form a solder contact on the exposed portion of the metal contact pad; and  
 annealing the solder contact to form the solder ball contact.  
 
   
   
   
       45 . The memory system of  claim 44 , wherein the molten solder comprises at least one material selected from the group consisting of lead, tin and bismuth.  
   
   
       46 . A memory system comprising: 
 a controller;    a command link coupled to the controller;    a data link coupled to the controller; and    a memory device coupled to the command link and the data link, wherein the memory device comprises: 
 an integrated circuit supported by a substrate;  
 a metal pattern line coupled to the integrated circuit;  
 a metal contact pad coupled to the metal pattern line; and  
 a solder ball contact coupled to the metal contact pad, wherein the solder ball contact is formed by a method, the method including: 
 forming an insulating layer on the metal contact pad;  
 removing a portion of the insulating layer to expose a portion of the metal contact pad, thereby forming an exposed portion of the metal contact pad;  
 adsorbing reactants on the exposed portion of the metal contact pad;  
 reacting the reactants on the exposed portion of the metal contact pad, thereby forming a solder contact; and  
 annealing the solder contact to form the solder ball contact.  
 
   
   
   
       47 . A memory system comprising: 
 a controller;    a command link coupled to the controller;    a data link coupled to the controller; and    a memory device coupled to the command link and the data link, wherein the memory device comprises: 
 an integrated circuit supported by a substrate;  
 a metal pattern line coupled to the integrated circuit;  
 a metal contact pad coupled to the metal pattern line; and  
 a solder ball contact coupled to the metal contact pad, wherein the solder ball contact is formed by a method, the method including: 
 forming an insulating layer on the metal contact pad;  
 forming a resist layer on the insulating layer;  
 patterning the resist layer to define a future exposed portion of the metal contact pad;  
 removing a portion of the insulating layer to expose a portion of the metal contact pad, thereby forming the exposed portion of the metal contact pad;  
 electrolytically depositing solder on the exposed portion of the metal contact pad, thereby forming a solder contact;  
 removing the resist layer, thereby exposing the solder contact above a surface of the insulating layer; and  
 annealing the solder contact to form the solder ball contact.  
 
   
   
   
       48 . The memory system of  claim 47 , wherein the solder comprises at least one material selected from the group consisting of lead, tin and bismuth.  
   
   
       49 . A semiconductor die comprising: 
 an integrated circuit supported by a substrate;    a metal pattern line coupled to the integrated circuit;    a metal contact pad coupled to the metal pattern line; and    a solder ball contact coupled to the metal contact pad, wherein the solder ball contact is formed by a method, the method including: 
 forming an insulating layer on the metal contact pad;  
 forming a patterned resist layer over the insulating layer;  
 using the patterned resist layer as a mask to remove a portion of the insulating layer to expose a portion of the metal contact pad, thereby forming an exposed portion of the metal contact pad;  
 depositing solder on the exposed portion of the metal contact pad after the patterned resist layer is removed, thereby forming a solder contact; and  
 annealing the solder contact to form the solder ball contact.  
   
   
   
       50 . The semiconductor die of  claim 49 , wherein depositing solder on the exposed portion of the metal contact pad uses a deposition process selected from a group consisting of selective chemical vapor deposition and selective electrolytic deposition.  
   
   
       51 . The semiconductor die of  claim 49 , wherein depositing solder on the exposed portion of the metal contact pad includes depositing solder only on the exposed portion of the metal contact without depositing solder on the insulating layer and without removing a remaining portion of the insulating layer.  
   
   
       52 . The semiconductor die of  claim 49 , wherein a remaining portion of the insulating layer remains in the semiconductor die after the resist layer is removed.  
   
   
       53 . The semiconductor die of  claim 49 , wherein the solder includes at least one material selected from the group consisting of lead, tin and bismuth.  
   
   
       54 . The semiconductor die of  claim 49 , wherein the metal contact pad includes a stack of zirconium, nickel, copper, gold, and lead.  
   
   
       55 . The semiconductor die of  claim 49 , wherein the exposed portion of the metal contact pad has a diameter, wherein the diameter has a dimension ranging from a first dimension to a second dimension greater than the first dimension, and wherein the first dimension is approximately 2 microns.