Study of magnetic tunnel junction read sensors

Ho, M.; Tsang, C.; Fontana, R.E.; Parkin, S. S. P.; Carey, K.; Pan, Tao; Macdonald, Scott; Arnett, P.; Moore, J.S.

doi:10.1109/20.950939

Cited by 21 publications

(11 citation statements)

References 1 publication

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This is obtained by locating the peak position of the transfer curve under longitudinal field excitation [2]. Fig.…”

Section: B Unshielded In-stack Biasing Experiments and Modelingmentioning

confidence: 99%

“…To study the feasibility of in-stack biasing as an alternative means of longitudinal stabilization, a simple quasi-static study was first performed on MTJ devices: an MTJ film was patterned into square sensors without any stabilization as described in a previous publication [2]. The size of these devices ranged from 4 m to as low as 0.1 m per side.…”

Section: A Feasibility Studymentioning

confidence: 99%

See 1 more Smart Citation

Study of Longitudinal Stabilization Using In-Stack Biasing

Tsang

Childress

et al. 2004

IEEE Trans. Magn.

Self Cite

View full text Add to dashboard Cite

The in-stack stabilization of unshielded and shielded magnetic tunnel junction (MTJ) sensors have been studied experimentally by quasi-static and recording tests as well as theoretically by micromagnetic modeling. Results showed the viability of in-stack stabilization over a range of design and material conditions. Performance tradeoff studies and design optimization results led to the fabrication of MTJ read heads with good magnetic stability and high readback sensitivity.Index Terms-Longitudinal recording, magnetic materials for heads, read and write theory and modeling, test and characterization.

show abstract

“…This is obtained by locating the peak position of the transfer curve under longitudinal field excitation [2]. Fig.…”

Section: B Unshielded In-stack Biasing Experiments and Modelingmentioning

confidence: 99%

Section: A Feasibility Studymentioning

confidence: 99%

Study of Longitudinal Stabilization Using In-Stack Biasing

Tsang

Childress

et al. 2004

IEEE Trans. Magn.

Self Cite

View full text Add to dashboard Cite

show abstract

“…In this scheme, the hard magnet can be in electrical contact [1] with the sensor [spin-valve sensor in Fig. 1(a)], or insulated [2], [3] from the sensor [tunnel-valve sensor in Fig. 1(b)].…”

Section: Introductionmentioning

confidence: 99%

“…IrMn and PtMn were deposited from vacuum-cast targets with Ir Mn and Pt Mn (atomic %) composition, resulting in film compositions of Ir Mn and Pt Mn , respectively. To easily reset the IrMn layer independently from the PtMn layer, the IrMn thickness is chosen to keep the IrMn blocking temperature below 230 C[3] while the PtMn blocking temperature is well above 250 C. The Al O tunnel barrier was formed by deposition of 6-7 Al metal and in situ oxidation by exposure to 500-mtorr O for 15 min. The resulting magnetic tunnel junction displayed about 25% tunnel magnetoresistance at room temperature, with a specific junction resistance of about 20…”

mentioning

confidence: 99%

Spin-valve and tunnel-valve structures with in situ in-stack bias

Childress

Fontana

et al. 2002

IEEE Trans. Magn.

Self Cite

View full text Add to dashboard Cite

The use of in-stack longitudinal magnetic stabilization for spin-valve and tunnel-valve recording head sensors has been investigated. An in-stack ferromagnetic layer pinned with an IrMn antiferromagnet is used to magnetostatically stabilize the free layer by flux closure. The use of IrMn with lower blocking temperature than PtMn allows the bias layer to be set independently from the PtMn-pinned reference layer in the spin-valve or tunnel-valve. A Ta spacer 10-30 A in thickness is used to separate the free layer from the bias layer resulting in low coupling fields. IrMn delivers up to 0.34 erg/cm 2 of pinning strength, resulting in stable unshielded sensor operation for device sizes below 0.2 m.

show abstract

“…In addition, measurements as a function of position on a square tunnel junction pad are used to investigate the sensitivity of the measurement results to probe misalignment. Since their discovery by Jullière, 1 magnetic tunnel junctions (MTJ) have attracted considerable interest due to the multitude of applications as sensors, 2 read heads in hard disc drives, [3][4][5][6][7] and, in particular, their use in magnetoresistive random-access memory (MRAM). 4,[8][9][10] MRAM has the potential to become the preferred memory technology of the future, due to the outstanding technical performance, such as high speed, high density, non-volatility, reliability, and very low power consumption.…”

mentioning

confidence: 99%

Characterization of magnetic tunnel junction test pads

Østerberg

Kjær

Nielsen³

et al. 2015

Journal of Applied Physics

View full text Add to dashboard Cite

We show experimentally as well as theoretically that patterned magnetic tunnel junctions can be characterized using the current-in-plane tunneling (CIPT) method, and the key parameters, the resistance-area product (RA) and the tunnel magnetoresistance (TMR), can be determined. The CIPT method relies on four-point probe measurements performed with a range of different probe pitches and was originally developed for infinite samples. Using the method of images, we derive a modified CIPT model, which compensates for the insulating boundaries of a finite rectangular sample geometry. We measure on square tunnel junction pads with varying sizes and analyze the measured data using both the original and the modified CIPT model. Thus, we determine in which sample size range the modified CIPT model is needed to ensure validity of the extracted sample parameters, RA and TMR. In addition, measurements as a function of position on a square tunnel junction pad are used to investigate the sensitivity of the measurement results to probe misalignment.

show abstract

Study of magnetic tunnel junction read sensors

Cited by 21 publications

References 1 publication

Study of Longitudinal Stabilization Using In-Stack Biasing

Study of Longitudinal Stabilization Using In-Stack Biasing

Spin-valve and tunnel-valve structures with in situ in-stack bias

Characterization of magnetic tunnel junction test pads

Contact Info

Product

Resources

About