Preface |
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xi | |
Author Biographies |
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xiv | |
List of Cited Tables and Figures |
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xvi | |
1 Basic Electromagnetism |
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1 | (18) |
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1 | (1) |
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1.2 Magnetic Force, Pole, Field, and Dipole |
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1 | (2) |
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1.3 Magnetic Dipole Moment, Torque, and Energy |
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3 | (2) |
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1.4 Magnetic Flux and Magnetic Induction |
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5 | (1) |
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1.5 Ampere's Circuital Law, Biot-Savart Law, and Magnetic Field from Magnetic Material |
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6 | (5) |
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1.5.1 Ampere's Circuital Law |
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6 | (2) |
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8 | (2) |
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1.5.3 Magnetic Field from Magnetic Material |
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10 | (1) |
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1.6 Equations, cgs-SI Unit Conversion Tables |
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11 | (2) |
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13 | (4) |
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17 | (2) |
2 Magnetism and Magnetic Materials |
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19 | (48) |
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19 | (1) |
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2.2 Origin of Magnetization |
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19 | (9) |
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2.2.1 From Ampere to Einstein |
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19 | (2) |
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21 | (1) |
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22 | (2) |
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2.2.4 Spin-Orbit Interaction |
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24 | (1) |
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25 | (3) |
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2.3 Classification of Magnetisms |
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28 | (14) |
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30 | (1) |
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30 | (4) |
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34 | (3) |
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37 | (3) |
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40 | (2) |
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2.4 Exchange Interactions |
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42 | (7) |
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43 | (2) |
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2.4.2 Indirect Exchange: Superexchange |
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45 | (1) |
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2.4.3 Indirect Exchange: RKKY Interaction |
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46 | (2) |
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2.4.4 Dzyaloshinskii-Moriya Interaction (DMI) |
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48 | (1) |
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2.5 Magnetization in Magnetic Metals and Oxides |
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49 | (2) |
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2.5.1 Slater-Pauling Curve |
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49 | (1) |
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50 | (1) |
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2.5.3 Iron Oxides and Iron Garnets |
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51 | (1) |
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2.6 Phenomenology of Magnetic Anisotropy |
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51 | (3) |
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2.6.1 Uniaxial Anisotropy |
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52 | (1) |
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53 | (1) |
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2.7 Origins of Magnetic Anisotropy |
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54 | (3) |
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55 | (1) |
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2.7.2 Magnetocrystalline Anisotropy (MCA) |
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56 | (1) |
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2.7.3 Perpendicular Magnetic Anisotropy (PMA) |
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57 | (1) |
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2.8 Magnetic Domain and Domain Walls |
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57 | (3) |
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58 | (1) |
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2.8.2 Single Domain and Superparamagnetism |
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59 | (1) |
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60 | (4) |
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64 | (3) |
3 Magnetic Thin Films |
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67 | (10) |
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67 | (1) |
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3.2 Magnetic Thin Film Growth |
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67 | (5) |
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68 | (3) |
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3.2.2 Molecular Beam Epitaxy (MBE) |
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71 | (1) |
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3.3 Magnetic Thin Film Characterization |
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72 | (4) |
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3.3.1 Vibrating-Sample Magnetometer (VSM) |
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73 | (1) |
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3.3.2 Magneto-Optical Kerr Effect (MOKE) |
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74 | (2) |
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76 | (1) |
4 Magnetoresistance Effects |
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77 | (16) |
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77 | (1) |
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4.2 Anisotropic Magnetoresistance (AMR) |
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78 | (1) |
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4.3 Giant Magnetoresistance (GMR) |
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79 | (2) |
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4.4 Tunneling Magnetoresistance (TMR) |
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81 | (3) |
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4.5 Contemporary MTJ Designs and Characterization |
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84 | (5) |
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4.5.1 Perpendicular MTJ (p-MTJ) |
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85 | (1) |
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4.5.2 Fully Functional p-MTJ |
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85 | (2) |
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4.5.3 CIPT Approach for TMR Characterization |
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87 | (2) |
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89 | (1) |
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89 | (4) |
5 Magnetization Switching and Field MRAMs |
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93 | (12) |
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93 | (1) |
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5.2 Magnetization Reversible Rotation and Irreversible Switching Under External Field |
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93 | (6) |
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5.2.1 Magnetization Rotation Under an External Field in the Hard Axis Direction |
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94 | (1) |
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5.2.2 Magnetization Rotation and Switching Under an external Field in the Easy Axis Direction |
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95 | (1) |
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5.2.3 Magnetization Rotation and Switching Under Two Orthogonal External Fields |
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96 | (1) |
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5.2.4 Magnetization Behavior of a Synthetic Anti-ferromagnetic Film Stack |
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97 | (2) |
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99 | (3) |
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100 | (1) |
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5.3.2 Half-Select Bit Disturbance Issue |
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101 | (1) |
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102 | (1) |
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103 | (2) |
6 Spin Current and Spin Dynamics |
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105 | (46) |
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6.1 Introduction to Hall Effects |
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105 | (4) |
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6.1.1 Ordinary Hall Effect |
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105 | (1) |
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6.1.2 Anomalous Hall Effect and Spin Hall Effect |
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106 | (3) |
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109 | (7) |
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6.2.1 Electron Spin Polarization in NM/FM/NM Film Stack |
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109 | (2) |
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6.2.2 Spin Current Injection, Diffusion, and Inverse Spin Hall Effect |
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111 | (3) |
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6.2.3 Generalized Carrier and Spin Current Drift-Diffusion Equation |
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114 | (2) |
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116 | (8) |
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6.3.1 Landau-Lifshitz and Landau-Lifshitz-Gilbert Equations of Motion |
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116 | (2) |
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6.3.2 Ferromagnetic Resonance |
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118 | (2) |
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6.3.3 Spin Pumping and Effective Damping in FM/NM Film Stack |
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120 | (2) |
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6.3.4 FM/NM/FM Coupling Through Spin Current |
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122 | (2) |
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6.4 Interaction Between Polarized Conduction Electrons and Local Magnetization |
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124 | (10) |
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6.4.1 Electron Spin Torque Transfer to Local Magnetic Magnetization |
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124 | (1) |
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125 | (2) |
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6.4.3 Spin-Torque Transfer in a Spin Valve |
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127 | (4) |
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6.4.3.1 Switching Threshold Current Density |
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128 | (1) |
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129 | (2) |
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6.4.4 Spin-Torque Transfer Switching in Magnetic Tunnel Junction |
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131 | (2) |
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6.4.5 Spin-Torque Ferromagnetic Resonance and Torkance |
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133 | (1) |
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6.5 Spin Current Interaction with Domain Wall |
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134 | (4) |
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6.5.1 Domain Wall Motion under Spin Current |
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135 | (2) |
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6.5.2 Threshold Current Density |
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137 | (1) |
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138 | (6) |
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144 | (7) |
7 Spin-Torque-Transfer (511) MRAM Engineering |
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151 | (54) |
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151 | (1) |
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7.2 Thermal Stability Energy and Switching Energy |
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152 | (2) |
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7.3 STT Switching Properties |
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154 | (12) |
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7.3.1 Switching Probability and Write Error Rate (WER) |
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156 | (4) |
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7.3.2 Switching Current in Precessional Regime |
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160 | (1) |
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7.3.3 Switching Delay of an STT-MRAM Cell |
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161 | (1) |
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161 | (1) |
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7.3.5 Switching Under a Magnetic Field - Phase Diagram |
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162 | (2) |
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7.3.6 MTJ Switching Abnormality |
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164 | (1) |
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7.3.6.1 Magnetic Back-Hopping |
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164 | (1) |
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7.3.6.2 Bifurcation Switching (Ballooning in WER) |
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165 | (1) |
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7.3.6.3 Domain Mediated Magnetization Reversal |
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166 | (1) |
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7.4 The Integrity of MTJ Tunnel Barrier |
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166 | (3) |
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7.4.1 MgO Degradation Model |
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167 | (2) |
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169 | (4) |
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7.5.1 Retention Determination Based on Bit Switching Probability |
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169 | (1) |
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7.5.2 Energy Barrier Determination Based on Aiding Field |
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170 | (1) |
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7.5.3 Energy Barrier Extraction with Retention Bake at Chip Level |
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171 | (2) |
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7.5.4 Data Retention Fail at the Chip Level |
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173 | (1) |
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7.6 The Cell Design Considerations and Scaling |
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173 | (15) |
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7.6.1 STT-MRAM Bit Cell and Array |
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174 | (1) |
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174 | (2) |
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7.6.3 Cell Switching Efficiency |
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176 | (1) |
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7.6.4 Cell Design Considerations |
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177 | (5) |
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7.6.4.1 WRITE Current and Cell Size |
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178 | (1) |
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7.6.4.2 READ Access Performance and RA Product of MTJ |
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178 | (1) |
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7.6.4.3 READ and WRITE Voltage Margins |
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178 | (1) |
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7.6.4.4 Stray Field Control for Perpendicular MTJ |
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179 | (2) |
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7.6.4.5 Suppress Stochastic Switching Time Variation Ideas |
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181 | (1) |
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7.6.5 The Scaling of MTJ for Memory |
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182 | (6) |
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183 | (1) |
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7.6.5.2 Out-of-Plane (Perpendicular) MTJ |
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184 | (4) |
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188 | (3) |
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7.7.1 Basic MTJ Equivalent Circuit Model for Circuit Design Simulation |
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188 | (1) |
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7.7.2 MTJ SPICE Circuit Model with Embedded Macrospin Calculator |
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189 | (2) |
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7.8 Test Chip, Test, and Chip-Level Weak Bit Screening |
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191 | (4) |
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192 | (1) |
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7.8.2 Write Marginal Bits |
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193 | (1) |
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7.8.3 Short Retention Bits |
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193 | (1) |
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194 | (1) |
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195 | (2) |
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197 | (8) |
8 Advanced Switching MRAM Modes |
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205 | (36) |
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205 | (1) |
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8.2 Current-Induced-Domain-Wall Motion (CIDM) Memory |
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206 | (5) |
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207 | (2) |
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8.2.2 Multibit Cell: Racetrack |
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209 | (2) |
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8.3 Spin-Orbit Torque (SOT) Memory |
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211 | (13) |
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8.3.1 Spin Orbit Torque (SOT) MRAM Cells |
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211 | (8) |
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8.3.1.1 In-Plane SOT Cell |
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212 | (6) |
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8.3.1.2 Perpendicular SOT Cell |
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218 | (1) |
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8.3.2 Materials Choice for SOT-MRAM Cell |
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219 | (5) |
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8.3.2.1 Transition Metals and their Alloys |
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219 | (2) |
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8.3.2.2 Emergent Materials Systems |
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221 | (1) |
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8.3.2.3 Benchmarking of SOT Switching Efficiency |
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222 | (2) |
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8.4 Magneto-Electric Effect and Voltage-Control Magnetic Anisotropy (VCMA) MRAM |
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224 | (7) |
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8.4.1 Magneto-Electric Effects |
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224 | (3) |
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8.4.2 VCMA-Assisted MRAMs |
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227 | (15) |
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8.4.2.1 VCMA-Assisted Field-MRAM |
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227 | (2) |
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8.4.2.2 VCMA-Assisted Multi-bit-Word SOT-MRAM |
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229 | (1) |
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8.4.2.3 VCMA-Assisted Precession-Toggle MRAM |
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229 | (2) |
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8.5 Relative Merit of Advanced Switching Mode MRAMs |
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231 | (2) |
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233 | (1) |
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233 | (8) |
9 MRAM Applications and Production |
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241 | (36) |
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241 | (1) |
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9.2 Intrinsic Characteristics and Product Attributes of Emerging Nonvolatile Memories |
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242 | (5) |
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9.2.1 Intrinsic Properties |
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243 | (1) |
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244 | (3) |
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9.3 Memory Landscape and MRAM Opportunity |
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247 | (19) |
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9.3.1 MRAM as Embedded Memory in Logic Chips |
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248 | (6) |
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9.3.1.1 Integration Issues of Embedded MRAM |
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248 | (1) |
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9.3.1.2 MRAM as Embedded Flash in Microcontroller |
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249 | (1) |
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9.3.1.3 Embedded MRAM Cell Size |
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250 | (1) |
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9.3.1.4 MRAM as Cache Memory in Processor |
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250 | (1) |
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9.3.1.5 Improvement of Access Latency |
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251 | (3) |
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9.3.2 High-Density Discrete MRAM |
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254 | (4) |
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9.3.2.1 Technology Status |
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254 | (2) |
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9.3.2.2 Ideal CMOS Technology for High-Density MRAM |
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256 | (2) |
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9.3.2.3 Improvement to Endurance and Write Error Rate with Error Buffer in Chip Architecture |
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258 | (1) |
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9.3.3 Applications and Market Opportunity of MRAM |
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258 | (8) |
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9.3.3.1 Battery-Backed DRAM Applications |
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260 | (1) |
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9.3.3.2 Internet of Things (IoT) and Cybersecurity Applications |
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261 | (3) |
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9.3.3.3 Applications to In-Memory Computing, and Artificial Intelligence (AI) |
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264 | (1) |
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9.3.3.4 MRAM-Based Memory-Driven Computer |
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265 | (1) |
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266 | (5) |
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9.4.1 MRAM Production Ecosystem |
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266 | (1) |
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9.4.2 MRAM Product History |
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267 | (4) |
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9.4.2.1 First-Generation MRAM - Field MRAM (Also Called Toggle MRAM) |
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268 | (1) |
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9.4.2.2 The Second-Generation MRAM - STT-MRAM |
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269 | (1) |
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9.4.2.3 The Potential Third-Generation MRAM - SOT MRAM |
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270 | (1) |
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271 | (1) |
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271 | (6) |
Appendix A Retention Bake (Including Two-Way Flip) |
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277 | (2) |
Appendix B Memory Functionality-Based Scaling |
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279 | (20) |
Appendix C High-Bandwidth Design Considerations for STT-MRAM |
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299 | (24) |
Index |
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