# US 8,273,233 B2 · Method to reduce void formation during trapezoidal write pole plating in perpendicular recording > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 8,273,233 B2 - Document ID: US8273233B2 - Status: Granted - Kind: B2 - Application number: 12/460,432 - Filed: 2009-07-17 - Published: 2011-01-20 - Granted: 2012-09-25 - Earliest claimed: 2009-07-17 - Assignees: Headway Technologies, Inc. - Inventors: Chao-Peng Chen; Jas Chudasama; Situan Lam; Chien-Li Lin - Web page: https://patentgrep.com/patent/US8273233B2 ## CPC - C25D 5/022: {using masking means} - C25D 5/18: Electroplating using modulated, pulsed or reversing current - C25D 5/611: {Smooth layers} - C25D 5/617: {Crystalline layers} - C25D 7/001: {Magnets} - G11B 5/1278: {specially adapted for magnetisations perpendicular to the surface of the record carrier} - G11B 5/3116: {Shaping of layers, poles or gaps for improving the form of the electrical signal transduced, e.g. for shielding, contour effect, equalizing, side flux fringing, cross talk reduction between heads or between heads and information tracks (G11B5/3113, G11B5/245 take precedence)} - G11B 5/3163: {Fabrication methods or processes specially adapted for a particular head structure, e.g. using base layers for electroplating, using functional layers for masking, using energy or particle beams for shaping the structure or modifying the properties of the basic layers} - C25D: PROCESSES FOR THE ELECTROLYTIC OR ELECTROPHORETIC PRODUCTION OF COATINGS; ELECTROFORMING; APPARATUS THEREFOR - G11B: INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER (recording measured values in a way that does not require playback through a transducer G01D9/00; recording or playback apparatus using mechanically marked tape, e.g. punched paper tape, or using unit records, e.g. punched or magnetically marked cards G06K; transferring data from one type of record carrier to another G06K1/18; circuits for coupling output of reproducer to radio receiver H04B1/20; gramophone pick-ups or like acoustic electromechanical transducers or circuits therefor H04R) ## Abstract A method of forming a write pole in a PMR head is disclosed that involves forming an opening in a mold forming layer. A conformal Ru seed layer is formed within the opening and on a top surface. An auxiliary layer made of CoFeNi or alloys thereof is formed as a conformal layer on the seed layer. All or part of the auxiliary layer is removed in an electroplating solution by applying a (−) current or voltage during an activation step that is controlled by activation time. Thereafter, a magnetic material is electroplated with a (+) current to fill the opening and preferably has the same CoFeNi composition as the auxiliary layer. The method avoids Ru oxidation that causes poor adhesion to CoFeNi, and elevated surfactant levels that lead to write pole impurities. Voids in the plated material are significantly reduced by forming a seed layer surface with improved wettability. ## Claims ### Claim 1 A method of forming a write pole in a perpendicular magnetic recording head, comprising: (a) forming an opening in a mold forming layer having a top surface, said opening has a bottom that exposes a portion of a substrate and has sidewalls that extend from the top surface to said substrate; (b) forming a conformal Ru seed layer along the top surface and sidewalls, and on the bottom of the opening in a deposition chamber; (c) depositing an auxiliary layer on the seed layer in the deposition chamber wherein said auxiliary layer conforms to a top surface of the seed layer and has a composition represented by CoxFeyNiz or oxides or alloys thereof wherein each of x, y, and z is from 0 to 100 atomic % and x+y+z=100 atomic %; (d) removing all or a portion of the auxiliary layer in an electroplating solution; and (e) performing an electroplating process in said electroplating solution that deposits a magnetic material which fills said opening. ### Claim 2 (depends on 1) The method of claim 1 wherein the mold forming layer is a composite layer comprised of a lower alumina layer and an upper Ta layer. ### Claim 3 (depends on 1) The method of claim 1 wherein the auxiliary layer has a thickness between about 10 and 1000 Angstroms. ### Claim 4 (depends on 1) The method of claim 1 wherein both of the seed layer and auxiliary layer are deposited in the same chamber after a single pump down process by a CVD, ALD, sputter deposition, or ion beam deposition technique. ### Claim 5 (depends on 1) The method of claim 1 wherein the auxiliary layer removal includes applying a first current or voltage to the substrate in the electroplating solution during an activation step and electroplating the magnetic material comprises applying a second current or voltage to the substrate in said electroplating solution, the second current has a sign opposite to that of the first current. ### Claim 6 (depends on 5) The method of claim 5 wherein the first current is direct current (DC), pulsed current (PC), pulsed reversal (PR) current, or a combination of PC and PR current. ### Claim 7 (depends on 5) The method of claim 5 wherein the activation step is controlled by activation time which is the time the negative current or voltage is applied. ### Claim 8 (depends on 1) The method of claim 1 further comprised of performing a chemical mechanical polish process to planarize the magnetic material electroplated in said opening. ### Claim 9 (depends on 1) The method of claim 1 wherein the opening has a trapezoidal shape where a top of the opening has a greater width than the bottom of the opening. ### Claim 10 (depends on 1) The method of claim 1 wherein the auxiliary layer and the electroplated magnetic material have the same composition. ### Claim 11 A method of forming a write pole in a perpendicular magnetic recording head, comprising: (a) forming an opening in a mold forming layer having a top surface, said opening has a bottom that exposes a portion of a substrate and has sidewalls that extend from the top surface to said substrate; (b) forming a conformal Ru seed layer along the top surface and sidewalls, and on the bottom of the opening; (c) depositing an auxiliary layer on the seed layer by an electroless method wherein said auxiliary layer conforms to a top surface of the seed layer and has a composition represented by CoxFeyNiz or oxides or alloys thereof wherein each of x, y, and z is from 0 to 100 atomic % and x+y+z=100 atomic %; (d) removing all or a portion of the auxiliary layer in an electroplating solution; and (e) performing an electroplating process in said electroplating solution that deposits a magnetic material which fills said opening. ### Claim 12 (depends on 11) The method of claim 11 wherein the mold forming layer is a composite layer comprised of a lower alumina layer and an upper Ta layer. ### Claim 13 (depends on 11) The method of claim 11 wherein the auxiliary layer has a thickness between about 10 and 1000 Angstroms. ### Claim 14 (depends on 11) The method of claim 11 wherein the auxiliary layer removal includes applying a first current or voltage to the substrate in the electroplating solution during an activation step and electroplating the magnetic material comprises applying a second current or voltage to the substrate in said electroplating solution, the second current has a sign opposite to that of the first current. ### Claim 15 (depends on 14) The method of claim 14 wherein the first current is direct current (DC), pulsed current (PC), pulsed reversal (PR) current, or a combination of PC and PR current. ### Claim 16 (depends on 14) The method of claim 14 wherein the activation step is controlled by activation time which is the time the negative current or voltage is applied. ### Claim 17 (depends on 11) The method of claim 11 further comprised of performing a chemical mechanical polish process to planarize the magnetic material electroplated in said opening. ### Claim 18 (depends on 11) The method of claim 11 wherein the opening has a trapezoidal shape where a top of the opening has a greater width than the bottom of the opening. ### Claim 19 (depends on 11) The method of claim 11 wherein the auxiliary layer and the electroplated magnetic material have the same composition. ### Claim 20 (depends on 19) The method of claim 19 wherein the auxiliary layer and electroplated magnetic material are an alloy of CoxFeyNiz that includes one or more elements selected from V, Hf, Zr, W, and Nb. ### Claim 21 (depends on 11) The method of claim 11 further comprising a step of rinsing the substrate after the electroless plating process and before removing all or a portion of the auxiliary layer in an electroplating solution.