# US 8,771,847 B2 · Reader stop-layers > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 8,771,847 B2 - Document ID: US8771847B2 - Status: Granted - Kind: B2 - Application number: 13/274,139 - Filed: 2011-10-14 - Published: 2013-04-18 - Granted: 2014-07-08 - Earliest claimed: 2011-10-14 - Assignees: Seagate Technology LLC - Applicants: Carolyn Pitcher Van Dorn; Thomas Roy Boonstra; Eric Walter Singleton; Shaun Eric McKinlay - Inventors: Carolyn Pitcher Van Dorn; Thomas Roy Boonstra; Eric Walter Singleton; Shaun Eric McKinlay - Web page: https://patentgrep.com/patent/US8771847B2 ## CPC - G11B 5/39: using magneto-resistive devices {or effects} - G11B 5/11: Shielding of head against electric or magnetic fields - G11B 5/112: {Manufacture of shielding device} - G11B 5/3169: {Working or finishing the interfacing surface of heads, e.g. lapping of heads} - G11B 5/3912: {Arrangements in which the active read-out elements are transducing in association with active magnetic shields, e.g. magnetically coupled shields (G11B5/3916 takes precedence)} - G11B 5/40: Protective measures on heads, e.g. against excessive temperature (G11B5/31 takes precedence; protection against wear G11B5/255 {; protective structure of the head: see under structures, e.g. G11B5/3106}) - Y10T 428/1121: Multilayer - Y10T 428/1164: with protective film - 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) - Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION ## Abstract Tolerances for manufacturing reader structures for transducer heads continue to grow smaller and storage density in corresponding storage media increases. Reader stop layers may be utilized during manufacturing of reader structures to protect various layers of the reader structure from recession and/or scratches while processing other non-protected layers of the reader structure. For example, the stop layer may have a very low polish rate during mechanical or chemical-mechanical polishing. Surrounding areas may be significantly polished while a structure protected by a stop layer with a very low polish rate is substantially unaffected. The stop layer may then be removed via etching, for example, after the mechanical or chemical-mechanical polishing is completed. ## Claims ### Claim 1 A read sensor comprising: a first stop layer that protects a directly adjacent shield element from recession during at least one of chemical polishing and mechanical polishing of the read sensor, wherein the first stop layer has a thickness less than about 20 angstroms. ### Claim 2 (depends on 1) The read sensor of claim 1, further comprising: a second stop layer that protects a directly adjacent alumina layer from recession during mechanical polishing of another adjacent layer. ### Claim 3 (depends on 1) The read sensor of claim 1, wherein the first stop layer protects a directly adjacent alumina insert from recession during mechanical polishing of adjacent re-deposition material. ### Claim 4 (depends on 2) The read sensor of claim 2, wherein the first stop layer is positioned between the shield element and the second stop layer. ### Claim 5 (depends on 1) The read sensor of claim 1, wherein the first stop layer comprises Ruthenium. ### Claim 6 A method of manufacturing a read sensor, comprising: depositing a first stop-layer directly adjacent to a shield element, wherein the first stop-layer protects the shield element from recession during at least one of chemical polishing and mechanical polishing of the read sensor, wherein the first stop layer has a thickness less than about 20 angstroms. ### Claim 7 (depends on 6) The method of claim 6, further comprising: depositing a second stop-layer that protects a directly adjacent insulating layer from recession during mechanical polishing of the read sensor. ### Claim 8 (depends on 7) The method of claim 7, wherein the insulating layer is an alumina insert. ### Claim 9 (depends on 7) The method of claim 7, wherein the first stop layer is positioned between the shield element and the second stop layer. ### Claim 10 (depends on 6) The method of claim 6, wherein the first stop-layer comprises Ruthenium. ### Claim 11 (depends on 6) The method of claim 6, further comprising: mechanically polishing material adjacent the shield element without causing significant recession of the first stop layer. ### Claim 12 A read element comprising: a stop-layer that protects an adjacent layer from recession during at least one of chemical polishing and mechanical polishing of the read element, wherein the stop layer has a thickness less than about 20 angstroms. ### Claim 13 (depends on 12) The read element of claim 12, wherein the stop layer is adjacent to re-deposition material. ### Claim 14 (depends on 12) The read element of claim 12, wherein the adjacent layer protected from recession is a layer of a reader stack. ### Claim 15 (depends on 12) The read element of claim 12, wherein the adjacent layer protected from recession is an alumina insert. ### Claim 16 (depends on 12) The read element of claim 12, wherein the stop-layer protects one or more free layers and spacer layers from recession during mechanical polishing of adjacent re-deposition material. ### Claim 17 (depends on 12) The read element of claim 12, wherein the stop-layer comprises Ruthenium. ### Claim 18 (depends on 12) The read element of claim 12, wherein the stop-layer comprises at least one of tantalum and chromium.