Superconformal electrodeposition of nickel iron and cobalt magnetic alloys

Abstract

A process for electrodepositing at least one ferromagnetic material into a three dimensional pattern within a substrate is provided. The process comprises providing a substrate material, dielectric or conductor, having a three dimensional recessed pattern in at least one outer surface thereof, dielectric substrate materials also having an electrical conductive seed layer at least within the three dimensional pattern. An electrolytic bath is prepared comprising at least one ferromagnetic material and at least one accelerating, inhibiting, or depolarizing additive. The at least one ferromagnetic material comprises at least one metal cation selected from the group consisting of Ni 2+ , Co 2+ , Fe 2+ , Fe 3+ , and combinations thereof. The substrate is placed into the electrolytic bath and the electrolytic bath contacts the conducting three dimensional pattern in the substrate or the conducting seed layer within the pattern on a dielectric substrate. A counter electrode is placed into the electrolytic bath. An electric current is passed through the electrolytic bath between the electrical conductive substrate or seed layer on the three dimensional substrate and the counter electrode. At least a portion of the ferromagnetic material is deposited into at least a portion of the three dimensional pattern wherein the at least one deposited ferromagnetic material is substantially void-free.

1 . A process of electrodepositing at least one ferromagnetic metal into a three dimensional pattern within a substrate comprising:
 providing a substrate material comprising an electrical conductive three dimensional recessed pattern in at least one surface thereof;   preparing an electrolytic bath comprising at least one ferromagnetic metal cation selected from the group consisting of Ni 2 + , Co 2+ , Fe 2+ , Fe 3+ , and combinations thereof;   mixing at least one accelerating, inhibiting, or depolarizing additive into said electrolytic bath;   placing said electrical conductive pattern of said substrate into said electrolytic bath; contacting said electrical conductive pattern of said substrate with said electrolytic bath;   placing a counter electrode into said electrolytic bath;   passing an electrical current through said electrolytic bath between said electrical conductive pattern of said substrate and said counter electrode;   said electrical current being passed between said electrical conductive pattern of said substrate and said counter electrode is such that the potential between the said substrate and a reference electrode is at a value negative of −0.8V SCE, or at an applied current density in the range of 0.1 to 50 mA/cm of the area of the electrically conductive pattern of the substrate, or both; and   depositing at least a portion of said at least one ferromagnetic material into at least a portion of said three dimensional pattern wherein said at least one deposited ferromagnetic material is substantially void-free.   
     
     
         2 . The process of  claim 1  wherein said substrate is a dielectric substrate and said process further comprises:
 depositing an electrical conductive material onto said three dimensional pattern of said dielectric substrate providing an electrical conductive seed layer on said substrate.   
     
     
         3 . The process of  claim 1  wherein said process step of preferentially depositing said ferromagnetic material into said three dimensional pattern results in a superconformal bottom-up deposition of said ferromagnetic material within said three dimensional pattern. 
     
     
         4 . The process of  claim 1  wherein said at least one accelerating, inhibiting, or depolarizing additive comprises a nitrogen containing compound. 
     
     
         5 . The process of  claim 1  wherein said at least one accelerating, inhibiting, or depolarizing additive has a compound selected from the group consisting of cationic surfactants, anionic surfactants, nonionic surfactants, heterocyclic benzimidazole derivatives, and combinations thereof. 
     
     
         6 . The process of  claim 1  wherein said at least one accelerating, inhibiting, or depolarizing additive comprises a compound selected from the group consisting of polyethyleneimine, 2-mercapto-5-benzimidazolesulfonic acid, and combinations thereof. 
     
     
         7 . The process of  claim 1  wherein said at least one accelerating, inhibiting, or depolarizing additive comprises polyethyleneimine. 
     
     
         8 . The process of  claim 1  wherein said at least one accelerating, inhibiting, or depolarizing additive comprises 2-mercapto-5-benzimidazolesulfonic acid. 
     
     
         9 . The process of  claim 8  wherein said 2-mercapto-5-benzimidazolesulfonic acid is in said electrolytic bath at a concentration of at least 50 μmol/L. 
     
     
         10 . The process of  claim 1  wherein said three dimensional structure has at least one trench or via with a width ranging from nanometers to macroscopic dimensions. 
     
     
         11 . A process of electrodepositing at least one ferromagnetic material into a three dimensional pattern within a substrate comprising:
 providing a substrate material having an electrical conductive portion with a three dimensional recessed pattern;   preparing an electrolytic bath comprising said at least one ferromagnetic material and at least one accelerating, inhibiting, or depolarizing additive;   said at least one ferromagnetic material comprising at least one metal cation selected from the group consisting of Ni 2+ , Co 2+ , Fe 2+ , Fe 3+ , and combinations thereof;   placing said electrical conductive portion of said substrate into said electrolytic bath;   contacting said electrical conductive portion of said substrate with said electrolytic bath;   placing a counter electrode into said electrolytic bath;   passing an electrical current through said electrolytic bath between said electrical conductive portion of said substrate and said counter electrode; and   depositing at least a portion of said at least one ferromagnetic material into at least a portion of said three dimensional pattern wherein said at least one deposited ferromagnetic material is substantially void-free.   
     
     
         12 . The process of  claim 11  wherein said process step of passing an electrical current through said electrolytic bath between said electrical conductive portion of said substrate and said counter electrode is such that the potential between the said substrate and a reference electrode is at a value negative of −0.8V SCE. 
     
     
         13 . The process of  claim 11  wherein said process step of passing an electrical current through said electrolytic bath between said electrical conductive portion of said substrate and said counter electrode is at an applied current density in the range of 0.1 to 50 mA/cm2 of the area of the electrically conductive portion of the substrate. 
     
     
         14 . The process of  claim 11  wherein said at least one accelerating, inhibiting, or depolarizing additive comprises a nitrogen containing compound. 
     
     
         15 . The process of  claim 11  wherein said at least one accelerating, inhibiting, or depolarizing additive has a compound selected from the group consisting of cationic surfactants, anionic surfactants, nonionic surfactants, heterocyclic benzimidazole derivatives, and combinations thereof. 
     
     
         16 . The process of  claim 11  wherein said at least one accelerating, inhibiting, or depolarizing additive comprises a compound selected from the group consisting of polyethyleneimine, 2-mercapto-5-benzimidazolesulfonic acid, and combinations thereof. 
     
     
         17 . The process of  claim 11  wherein said at least one accelerating, inhibiting, or depolarizing additive comprises polyethyleneimine. 
     
     
         18 . The process of  claim 11  wherein said at least one accelerating, inhibiting, or depolarizing additive comprises 2-mercapto-5-benzimidazolesulfonic acid. 
     
     
         19 . The process of  claim 18  wherein said 2-mercapto-5-benzimidazolesulfonic acid is in said electrolytic bath at a concentration of at least 50 μmol/L. 
     
     
         20 . A process of electrodepositing at least one ferromagnetic material into a three dimensional pattern within a substrate comprising:
 providing a substrate material having an electrical conductive three dimensional recessed pattern in a surface thereof;   preparing an electrolytic bath comprising said at least one ferromagnetic material and at least one accelerating, inhibiting, or depolarizing additive;   said at least one ferromagnetic material comprising at least one metal cation selected from the group consisting of Ni 2+ , Co 2+ , Fe 2+ , Fe 3+ , and combinations thereof;   said at least one accelerating, inhibiting, or depolarizing additive comprising an additive selected from the group consisting of polyethyleneimine, 2-mercapto-5-benzimidazolesulfonic acid, and combinations thereof;   placing said electrical conductive three dimensional recessed pattern in said substrate into said electrolytic bath;   contacting said electrical conductive three dimensional recessed pattern in said substrate with said electrolytic bath;   placing a counter electrode into said electrolytic bath;   passing an electrical current through said electrolytic bath between said electrical conductive three dimensional recessed pattern in said substrate and said counter electrode; and   depositing at least a portion of said at least one ferromagnetic material into at least a portion of said three dimensional recessed pattern in said substrate wherein said at least one deposited ferromagnetic material is substantially void-free.