Nanoscale Semiconductor Memories

8	Spin-Transfer-Torque MRAM Kangho Lee

CONTENTS

8.1    Introduction

8.1.1    Motivation for Embedded STT-MRAM: Application Perspectives

8.1.2    Recent Industrial Efforts for MRAM Development

8.2    Magnetic Tunnel Junction: Storage Element of STT-MRAM

8.2.1    Magnetization Dynamics in Ferromagnetic Metals

8.2.2    Tunneling Magnetoresistance Ratio

8.2.3    Energy Barrier for Data Retention

8.2.4    Spin-Transfer-Torque Switching

8.3    1T-1MTJ STT-MRAM Bitcell

8.3.1    Read Margin

8.3.2    Write Margin

8.4    Scalability of Embedded STT-MRAM

8.4.1    Perpendicular Magnetic Anisotropy

8.4.2    MTJ Material Engineering for Write Power Reduction

8.4.3    Bit Error Rates of STT-MRAM

References

8.1    INTRODUCTION

8.1.1    MOTIVATION FOR E