Method for manufacturing a narrow magnetic read width current perpendicular to plane magnetoresistive sensor

Abstract

A method for manufacturing a magnetic read head having a very narrow track width. The method includes the use of a non-Si containing photoresist to form a mask prior to ion milling to define the track-width of the sensor. Previously only Si-containing resists were used. The Si in the resist turned to an oxide, which allowed the photoresist to withstand the reactive ion etching used for image transfer to an underlying hard mask. The Si-containing resist, however, has limitations as to how small the mask can be made. It has been found that a non-Si-containing resist provides better resolution at very narrow track-width definition, and also provides good temperature resistance. Some modifications to the process allow the non-Si-containing resist to be used in the construction of the magnetic read sensor.

1 . A method for manufacturing a magnetoresistive read sensor, comprising:
 depositing a plurality of sensor layers;   depositing a non-Si-containing photoresist over the plurality of sensor layers;   patterning the non-Si-containing photoresist to define a sensor width; and   performing an ion milling to remove a portion of the plurality of sensor layers that are not protected by the photoresist, thereby forming a magnetoresistive sensor.   
     
     
         2 . The method as in  claim 1  further comprising, after depositing the plurality of sensor layers and before depositing the non-Si-containing photoresist, depositing a layer of material that is resistant to chemical mechanical polishing. 
     
     
         3 . The method as in  claim 2  wherein the material that is resistant to chemical mechanical polishing comprises Ru, Rh, Ir or diamond like carbon. 
     
     
         4 . The method as in  claim 1  further comprising, after performing the ion milling:
 depositing a non-magnetic, electrically insulating layer; 
 depositing a hard magnetic layer; and 
 performing an ion milling at a glancing angle; and 
 lifting off the photoresist mask. 
 
     
     
         5 . The method as in  claim 3  wherein the glancing ion milling is performed at an angle of 0-30 degrees relative to the planes of the as deposited sensor layers. 
     
     
         6 . The method as in  claim 2  further comprising, after performing the ion milling:
 depositing a layer of non-magnetic, electrically insulating material; 
 depositing a magnetic material over the non-magnetic, electrically insulating material; 
 depositing a second layer of material that is resistant to chemical mechanical polishing; 
 depositing a material that is resistant to ion milling; 
 performing a glancing ion milling; and 
 performing a chemical mechanical polishing. 
 
     
     
         7 . A method for manufacturing a magnetoresistive read sensor, comprising:
 depositing a plurality of sensor layers;   depositing a release layer;   depositing a non-Si-containing photoresist over the plurality of sensor layers;   patterning the non-Si-containing photoresist to define a sensor width;   performing a reactive ion etching to transfer the image of the photoresist onto the release layer; and   performing an ion milling to remove a portion of the plurality of sensor layers that are not protected by the photoresist, thereby forming a magnetoresistive sensor.   
     
     
         8 . The method as in  claim 7  wherein the ion milling is performed in an atomstphere that includes CO 2  and an inert gas that is chosen to slow the reactive ion etching process. 
     
     
         9 . The method as in  claim 7  wherein the release layer is a material that can also function as a Bottom Anti-Reflective Coating (BARC). 
     
     
         10 . The method as in  claim 7  wherein the release layer is a soluble polyimide. 
     
     
         11 . The method as in  claim 7 , further comprising:
 after depositing the sensor layers and before depositing the release layer, depositing first layer of material that is resistant to chemical mechanical polishing; and after performing the ion milling:   depositing a layer of non-magnetic, electrically insulating material;   depositing a magnetic material over the layer of non-magnetic, electrically insulating material;   depositing a second lager of material that is resistant to chemical mechanical polishing;   depositing a layer of material that is resistant to ion milling over the second layer of material that is resistant to chemical mechanical polishing;   performing a glancing ion milling; and   performing a chemical mechanical polishing.   
     
     
         12 . The method as in  claim 11  wherein the first and second materials that are resistant to chemical mechanical polishing each comprise Ru, Rh, Ir, or diamond like carbon, and the material that is resistant to ion milling comprises Ta or Al 2 O 3  Si 3 N 4 , SiO 2 , Ta 2 O 5  or DLC. 
     
     
         13 . The method as in  claim 6  wherein the first and second materials that are resistant to chemical mechanical polishing each comprise Ru, Rh, Ir, or diamond like carbon, and the material that is resistant to ion milling comprises Ta or Al 2 O 3  Si 3 N 4 , SiO 2 , Ta 2 O 5  or DLC. 
     
     
         14 . The method as in  claim 11  wherein the glancing ion milling is performed at an angle of 0-30 degrees relative to the plane of the as deposited sensor layers. 
     
     
         15 . A method for manufacturing a magnetoresistive read sensor, comprising:
 depositing a plurality of sensor layers;   depositing a release layer;   depositing a Bottom Anti-Reflective Coating (BARC);   depositing a non-Si-containing photoresist over the plurality of sensor layers;   patterning the non-Si-containing photoresist to define a sensor width;   performing a reactive ion etching to transfer the image of the photoresist onto the release layer; and   performing an ion milling to remove a portion of the plurality of sensor layers that are not protected by the photoresist, thereby forming a magnetoresistive sensor.   
     
     
         16 . The method as in  claim 15  wherein the BARC is a carbon-containing BARC. 
     
     
         17 . The method as in  claim 15  wherein the BARC is a Si-containing BARC. 
     
     
         18 . The method as in  claim 15  wherein the reactive ion etching is performed in an atmosphere containing CO 2  and a noble gas, the noble gas being added in a concentration to slow the reactive ion etching to protect the non-Si-containing photoresist. 
     
     
         19 . The method as in  claim 15 , further comprising:
 after depositing the sensor layers and before depositing the release layer, depositing first layer of material that is resistant to chemical mechanical polishing; and after performing the ion milling:   depositing a layer of non-magnetic, electrically insulating material;   depositing a magnetic material over the layer of non-magnetic, electrically insulating material;   depositing a second layer of material that is resistant to chemical mechanical polishing;   depositing a layer of material that is resistant to ion milling over the second layer of material that is resistant to chemical mechanical polishing;   performing a glancing ion milling; and   performing a chemical mechanical polishing.   
     
     
         20 . The method as in  claim 19  wherein the first and second layers of material that are resistant to chemical mechanical polishing each comprise Ru, Rh, Ir or diamond like carbon, and the layer of material that is resistant to ion milling Ta or Al 2 O 3 , Si 3 N 4 , SiO 2 , Ta 2 O 5  or DLC.