# US 2009/0260719 A1 · In-situ annealing of a tmr sensor > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2009/0260719 A1 - Document ID: US20090260719A1 - Status: Published application - Kind: A1 - Application number: 12/106,190 - Filed: 2008-04-18 - Published: 2009-10-22 - Earliest claimed: 2008-04-18 - Assignees: International Business Machines Corporation - Inventors: Icko E. Tim Iben - Web page: https://patentgrep.com/patent/US20090260719A1 ## CPC - G11B 5/84: Processes or apparatus specially adapted for manufacturing record carriers - B82Y 25/00: Nanomagnetism, e.g. magnetoimpedance, anisotropic magnetoresistance, giant magnetoresistance or tunneling magnetoresistance - B82Y 40/00: Manufacture or treatment of nanostructures - G01R 33/098: {comprising tunnel junctions, e.g. tunnel magnetoresistance sensors} - G11B 5/3106: {where the integrated or assembled structure comprises means for conditioning against physical detrimental influence, e.g. wear, contamination (G11B5/3133 takes 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} - G11B 5/3906: {Details related to the use of magnetic thin film layers or to their effects} - G11B 5/3909: {Arrangements using a magnetic tunnel junction} - G11B 5/3967: {Composite structural arrangements of transducers, e.g. inductive write and magnetoresistive read (G11B5/3906 takes precedence)} - H01F 10/3254: {the spacer being semiconducting or insulating, e.g. for spin tunnel junction [STJ]} - H01F 41/22: Heat treatment; Thermal decomposition; Chemical vapour deposition - H01F 41/302: {for applying spin-exchange-coupled multilayers, e.g. nanostructured superlattices (spin-exchange-coupled multilayers H01F10/32)} - H01F 41/304: {using temporary decoupling, e.g. involving blocking, Néel or Curie temperature transitions by heat treatment in presence/absence of a magnetic field} - H10N 50/01: Manufacture or treatment - 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 29/49021: Magnetic recording reproducing transducer [e.g., tape head, core, etc.] - Y10T 29/49034: Treating to affect magnetic properties - Y10T 29/49043: Depositing magnetic layer or coating - 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) - B82Y: SPECIFIC USES OR APPLICATIONS OF NANOSTRUCTURES; MEASUREMENT OR ANALYSIS OF NANOSTRUCTURES; MANUFACTURE OR TREATMENT OF NANOSTRUCTURES - G01R: MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES (indicating correct tuning of resonant circuits H03J3/12) - H01F: MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES - H10N: ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR - Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION ## Abstract A method in one embodiment includes applying a current to a lead of a tunneling magnetoresistance sensor for inducing joule heating of the lead or a heating layer, the level of joule heating being sufficient to anneal a magnetic layer of the sensor; and maintaining the current at the level for an amount of time sufficient to anneal the tunneling magnetoresistive (TMR) sensor. A system in one embodiment comprises a first lead coupled to one end of a tunneling magnetoresistance sensor stack; a second lead coupled to another end of the sensor stack; and a third lead coupled to the first lead, the third lead being selectively coupleable to a ground, wherein a current applied to the first lead at a predetermined level when the third lead is coupled to the ground induces joule heating of the first lead or a heating layer coupled to the first and third leads, the joule heating applied for a predetermined amount of time being sufficient to anneal a magnetic layer of the sensor. Additional systems and methods are also presented. ## Claims ### Claim 1 A method, comprising: applying a current to a lead of a tunneling magnetoresistance sensor for inducing joule heating of the lead or a heating layer, the level of joule heating being sufficient to anneal a magnetic layer of the sensor; and maintaining the current at the level for an amount of time sufficient to anneal the tunneling magnetoresistive (TMR) sensor. ### Claim 2 (depends on 1) A method as recited in claim 1, wherein the lead is also a lead used for applying a sense current to the sensor. ### Claim 3 (depends on 1) A method as recited in claim 1, wherein the lead is not used for applying a sense current to the sensor. ### Claim 4 (depends on 1) A method as recited in claim 1, wherein the current does not pass through the magnetic layer. ### Claim 5 (depends on 1) A method as recited in claim 1, wherein no external magnetic field is applied to the sensor during application of the current. ### Claim 6 (depends on 1) A method as recited in claim 1, wherein the current is applied in a drive having the sensor installed therein. ### Claim 7 (depends on 1) A method as recited in claim 1, wherein the drive is a tape drive. ### Claim 8 (depends on 1) A method as recited in claim 1, wherein the drive is a hard disk drive. ### Claim 9 (depends on 1) A method as recited in claim 1, further comprising applying a second current to a second lead of the sensor, the second lead being positioned on an opposite side of the tunnel junction layer as the first sensor, the second current reducing a voltage differential across the magnetic layer. ### Claim 10 A system, comprising: a first lead coupled to one end of a tunneling magnetoresistance sensor stack; a second lead coupled to another end of the sensor stack; and a third lead coupled to the first lead, the third lead being selectively coupleable to a ground, wherein a current passing through the first lead to the third lead when the third lead is coupled to the ground does not significantly traverse the sensor stack, wherein the first and third leads are characterized in that a current applied to the first lead at a predetermined level when the third lead is coupled to the ground induces joule heating of the first lead or a heating layer coupled to the first and third leads, the joule heating applied for a predetermined amount of time being sufficient to anneal a magnetic layer of the sensor. ### Claim 11 (depends on 10) A system as recited in claim 10, wherein the first lead is also used for applying a sense current to the sensor. ### Claim 12 (depends on 10) A system as recited in claim 10, wherein no external magnetic field is applied to the magnetic layer. ### Claim 13 (depends on 10) A system as recited in claim 10, wherein the current is applied in a drive having the sensor installed therein. ### Claim 14 (depends on 10) A system as recited in claim 10, further comprising a drive mechanism for passing a magnetic medium over the magnetic head, and a controller electrically coupled to the magnetic head. ### Claim 15 A system, comprising: a first lead coupled to one end of a tunneling magnetoresistance sensor stack; a second lead coupled to another end of the sensor stack; a third lead coupled to the first lead, the third lead being selectively coupleable to a ground; and a fourth lead coupled to the second lead, the fourth lead being selectively coupleable to the ground, wherein the first and third leads are characterized in that a current applied to the first lead at a predetermined level when the third lead is coupled to the ground induces joule heating of the first lead or a heating layer coupled to the first and third leads, wherein the second and fourth leads are characterized in that a current applied to the second lead at a predetermined level when the fourth lead is coupled to the ground induces joule heating of the second lead or a heating layer coupled to the second and fourth leads, the combined joule heating generated for a predetermined amount of time being sufficient to anneal a magnetic layer of the sensor. ### Claim 16 (depends on 15) A system as recited in claim 15, wherein no external magnetic field is applied to the magnetic layer. ### Claim 17 (depends on 15) A system as recited in claim 15, further comprising a drive mechanism for passing a magnetic medium over the magnetic head, and a controller electrically coupled to the magnetic head. ### Claim 18 A system, comprising: a tunneling magnetoresistance sensor; a heating layer for heating the sensor, the heating layer being external to a thin film stack of the sensor; and leads coupled to the heating layer, wherein the heating layer is characterized in that a current applied thereto at a predetermined level for a predetermined amount of time anneals a magnetic layer of the sensor.