Manos, Orestis: Perpendicular magnetic tunnel junctions based on CoFeB and MnIr/CoFe with exchange bias. 2019
Inhalt
- 1 Introduction
- 2 Fundamentals
- 2.1 Spintronics
- 2.2 Physical mechanisms of TMR effect
- 2.2.1 Julliére's Model
- 2.2.2 The Slonczewski model
- 2.2.3 Incoherent and coherent tunneling
- 2.2.4 Coherent tunneling: Prominent features and consequences
- 2.3 Origin of magnetic anisotropy in thin films
- 2.3.1 Surface and volume contributions
- 2.3.2 Direct and indirect contributions on the formation of PMA in underlayer/CoFeB/MgO systems
- 2.4 Exchange bias
- 2.5 Perpendicular EB in MnIr/CoFeB/MgO systems
- 2.6 Magnetostatic coupling effects in FM/NM/FM systems
- 2.6.1 IEC: Slonczewski and Bruno models
- 2.6.2 Orange peel coupling in systems with PMA
- 2.6.3 Methodology for the determination of magnetostatic coupling
- 2.7 Magnetic memories and sensors
- 2.7.1 Field-driven MRAM
- 2.7.2 Spin-Transfer Torque Magnetic Random Access Memory (STT-MRAM)
- 2.7.3 Magnetic sensors
- 2.8 p-MTJs vs. i-MTJs for MRAM applications
- 3 Sample preparation
- 3.1 Thin film fabrication
- 3.2 p-MTJ preparation via e-beam lithography
- 3.3 Structural analysis
- 3.4 Magnetic analysis
- 3.5 Chemical analysis
- 4 Experimental
- 4.1 Pinned electrode stacks based on MnIr/CoFe bilayers
- 4.2 Soft electrode stacks based on CoFeB
- 4.3 Ta-capped p-MTJs with exchange bias
- 4.4 Zr- and Hf-capped p-MTJs with exchange bias
- 4.5 Auger measurements
- 4.6 Voltage Control Magnetic Anisotropy measurements
- 5 Summary & Outlook
- 6 Publications