Abstract: A method of fabricating a magnetic device is described. A mask removing layer is formed on a layered sensing stack and a hard mask layer is formed on the mask removing layer. A first reactive ion etch is performed with a non-oxygen-based chemistry to define the hard mask layer using an imaged layer formed on the hard mask layer as a mask. A second reactive ion etch is performed with an oxygen-based chemistry to define the mask removing stop layer using the defined hard mask layer as a mask. A third reactive ion etch is performed to define the layered sensing stack using the hard mask layer as a mask. The third reactive ion etch includes an etching chemistry that performs at a lower etching rate on the hard mask layer than on the layered sensing stack.

Abstract: In some embodiments, a current perpendicular to the plane giant magneto-resistance (CPP GMR) read sensor may include a reference layer and/or a free layer that includes a plurality of sub-layers. For example, at least one of the reference layer or free layer may include a first ferromagnetic sub-layer, a second ferromagnetic sub-layer, and a Heusler alloy layer located between the first ferromagnetic sub-layer and the second ferromagnetic sub-layer. In some embodiments, a CPP GMR read sensor may include a current closed path (CCP) spacer layer between the reference layer and the free layer. The CCP spacer layer may include Ag and Al2O3. In further embodiments, a CPP GMR read sensor may include a Heusler alloy free layer, a Heusler alloy reference layer, and a CCP spacer layer.

Abstract: A close loop method for measuring head SNR, for a storage device comprising a storage media and a head, comprising steps of: (a) loading the head on the media with a dynamic fly height; (b) measuring an initial environmental temperature value Ti and measuring the head signal signalload; (c) unloading the head; (d) adjusting a power which controls the dynamic fly height until a real-time environmental temperature value T2 is equal to the initial environmental temperature T1; (e) measuring the head noise value noiseunload, (f) calculating the head SNR with the follow equation: Head_SNR = 20 × log ? ( signal load noise unload ) . The method of the present invention can obtain a fair condition between the signal and noise measurement, thereby a reliable and accurate head SNR can be obtain. The present invention also provides a close loop method for measuring media SNR.

Abstract: A reader sensor comprises a first shielding layer, a second shielding layer, a read element formed therebetween, and a pair of permanent magnet layer respectively placed on two sides of the read element; and it further comprises a magnetic field generating means formed beside the read element and arranged for providing a magnetic field with a direction perpendicular to the first shielding layer and the second shielding layer, thereby stabilizing the reading performance of the reader sensor. The invention can stabilize the reading performance, ameliorate the unstable defective reader sensor, and decrease the waste and the manufacturing cost. The present invention also discloses a magnetic head, a HGA and a disk drive unit.

Abstract: A method of testing anti-high temperature performance of a magnetic head comprises applying a plurality of second magnetic fields with different intensities in a second direction to the magnetic head, and measuring a second output parameter curve, and judging whether a variation that is beyond an allowable value is presented on the second output parameter curve, therein the second direction passes through the ABS and at an angle whose absolute value is an acute angle to the ABS. The present invention can screen out defective magnetic heads that possess poor anti-high temperature performance without heating the magnetic head.

Abstract: A method of testing anti-high temperature performance of a magnetic head comprises applying a second magnetic field with different intensities in a second direction and the changing first magnetic fields in a first direction, and measuring a plurality of second output parameter curves; and judging whether a variation that is beyond an allowable value is presented on the second output parameter curves, thereby screening out a defective magnetic head, therein the first direction is perpendicular to the air bearing surface of the magnetic head, and the second direction is perpendicular to the shielding layers of the magnetic head. The present invention can screen out defective magnetic heads that possess poor anti-high temperature performance without heating the magnetic head and with high precision.

Abstract: A slider for a head gimbal assembly includes a trailing surface, a plurality of connection pads arranged on the trailing surface adapted for both bonding the slider to a suspension of the head gimbal assembly and testing the performance of the slider. At least a part of the connection pads each comprises a bonding portion and a testing portion electrically connected to the bonding portion and larger than the bonding portion, all the bonding portions and the rest part of the connection pads are arranged in a first row and the testing portions are arranged outside the first row. The slider of the present invention has a new pad layout to facilitate bonding of the connection pads and permit to provide additional pads thereon to connect the additional sensors therein for precise reading and writing, thereby improving the performance of the slider. The invention also discloses a head gimbal assembly and a disk drive unit including the same.

Abstract: A method for measuring longitudinal bias magnetic field in a tunnel magnetoresistive sensor of a magnetic head, the method includes the steps of: applying an external longitudinal time-changing magnetic field onto the tunnel magnetoresistive sensor; determining a shield saturation value of the tunnel magnetoresistive sensor under the application of the external longitudinal time-changing magnetic field; applying an external transverse time-changing magnetic field and an external longitudinal DC magnetic field onto the tunnel magnetoresistive sensor; determining a plurality of different output amplitudes under the application of the external transverse time-changing magnetic field and the application of different field strength values of the external longitudinal DC magnetic field; plotting a graph according to the different output amplitudes and the different field strength values; and determining the strength of the longitudinal bias magnetic field according to the graph and the shield saturation value.

Abstract: A method for measuring the temperature rise induced by bias current/bias voltage in a magnetic tunnel junction, the method includes the steps of: (a) applying an external time-changing magnetic field to the magnetic tunnel junction; (b) measuring different first outer pin flip field values under different temperature values; (c) calculating the correlation between the temperature and the outer pin flip field according to the temperature values and the first outer pin flip field values; (d) measuring different second outer pin flip field values under different bias current/bias voltage values; (e) calculating the correlation between the bias current/bias voltage and the outer pin flip field according to the bias current/bias voltage values and the second outer pin flip field values; (f) calculating the correlation between the temperature and the bias current/bias voltage according to the results produced by the steps (c) and (e).

Abstract: A MR sensor comprises a first shielding layer, a second shielding layer, a MR element and a pair of hard magnet layers sandwiched therebetween, and a non-magnetic insulating layer formed at a side of the MR element far from an air bearing surface of a slider. The MR sensor further comprises a first non-magnetic conducting layer formed between the first shielding layer and the MR element, and the first non-magnetic conducting layer is embedded in the first shielding layer and kept separate from the ABS. The MR sensor of the invention can obtain a narrower read gap to increase the resolution power and improve the reading performance, and obtain a strong longitudinal bias field to stabilize the MR sensor so as to increase the total sensor area and, in turn, get an improved reliability and performance. The present invention also discloses a magnetic head, a HGA and a disk drive unit.

Abstract: A MR sensor includes a first shielding layer, a second shielding layer, a MR element formed therebetween, and a pair of hard magnet layers respectively placed on two sides of the MR element. The MR element comprises an AFM layer formed on the first shielding layer, a pinned layer formed on the AFM layer and a free layer formed between the pinned layer and the second shielding layer. The free layer is funnel-shaped, which having a first edge facing the air bearing surface and a second edge opposite the first edge, and the first edge has a narrower width than that of the second edge. The structure of the MR sensor can improve MR height control performance, and improve the ESD performance and decrease the PCN and RTN and, in turn, get a more stable performance. The present invention also discloses a magnetic head, a HGA and a disk drive unit.

Abstract: In some embodiments, a current perpendicular to the plane giant magneto-resistance (CPP GMR) read sensor may include a reference layer and/or a free layer that includes a plurality of sub-layers. For example, at least one of the reference layer or free layer may include a first ferromagnetic sub-layer, a second ferromagnetic sub-layer, and a Heusler alloy layer located between the first ferromagnetic sub-layer and the second ferromagnetic sub-layer. In some embodiments, a CPP GMR read sensor may include a current closed path (CCP) spacer layer between the reference layer and the free layer. The CCP spacer layer may include Ag and Al2O3. In further embodiments, a CPP GMR read sensor may include a Heusler alloy free layer, a Heusler alloy reference layer, and a CCP spacer layer.

Abstract: A slider for a head gimbal assembly includes a trailing surface, a plurality of connection pads arranged on the trailing surface adapted for both bonding the slider to a suspension of the head gimbal assembly and testing the performance of the slider. At least a part of the connection pads each comprises a bonding portion and a testing portion electrically connected to the bonding portion and larger than the bonding portion, all the bonding portions and the rest part of the connection pads are arranged in a first row and the testing portions are arranged outside the first row. The slier of the present invention has a new pad layout to facilitate bonding of the connection pads and permit to provide additional pads thereon to connect the additional sensors therein for precise reading and writing, thereby improving the performance of the slider. The invention also discloses a head gimbal assembly and a disk drive unit including the same.

Abstract: A method of fabricating a magnetic device is described. A mask removing layer is formed on a layered sensing stack and a hard mask layer is formed on the mask removing layer. A first reactive ion etch is performed with a non-oxygen-based chemistry to define the hard mask layer using an imaged layer formed on the hard mask layer as a mask. A second reactive ion etch is performed with an oxygen-based chemistry to define the mask removing stop layer using the defined hard mask layer as a mask. A third reactive ion etch is performed to define the layered sensing stack using the hard mask layer as a mask. The third reactive ion etch includes an etching chemistry that performs at a lower etching rate on the hard mask layer than on the layered sensing stack.

Abstract: A magnetoresistive device having a high giant magnetoresistance (GMR) value and a moderate low resistance area product (RA) includes a first magnetic layer, a second magnetic layer, and a current confined path (CCP) spacer layer positioned between the first magnetic layer and the second magnetic layer. The spacer layer includes copper current confined paths extending between the first magnetic layer and the second magnetic layer in a matrix of magnesium oxide. The spacer layer is formed by a mixture copper and magnesium oxide, which is heattreated to form the copper current confined paths within the magnesium oxide matrix.

Abstract: The present invention is a magnetoresistive (MR) sensor (100) that combines the advantages of abutted junction structure and regular overlaid structure. The abutted junction design is used with the soft adjacent layer (SAL) (108) and the overlaid structure is used with the MR element (120). The method of making the MR sensor (100) comprises depositing SAL (108) on top of the gap layer (106) and depositing spacer material (110) on top of the SAL (108). A mask (130) is placed over the central region of the spacer material (110) and SAL (108). The spacer material (110) and SAL (108) are removed in the areas not covered by the mask (130). An underlayer material (112) is deposited in the areas where the SAL (108) and spacer material (110) were removed. A hard-biasing material (114) is deposited on top of the underlayer (112).

Abstract: The present invention is a magnetoresistive (MR) sensor (100) that combines the advantages of abutted junction structure and regular overlaid structure. The abutted junction design is used with the soft adjacent layer (SAL) (108) and the overlaid structure is used with the MR element (120). The method of making the MR sensor (100) comprises depositing SAL (108) on top of the gap layer (106) and depositing spacer material (110) on top of the SAL (108). A mask (130) is placed over the central region of the spacer material (110) and SAL (108). The spacer material (110) and SAL (108) are removed in the areas not covered by the mask (130). An underlayer material (112) is deposited in the areas where the SAL (108) and spacer material (110) were removed. A hard-biasing material (114) is deposited on top of the underlayer (112).