The spin-based memory, spin transfer torque-magnetic random access memory (STT-MRAM), has the potential to enhance the power efficiency of high density memory systems. Its desirable characteristics include nonvolatility, fast operation, and long endurance. However, dry etching of MRAM structures remains a challenge as the industry is ramping up its production. In this paper, we explore the etching strategies that have been used to etch the MRAM structures. Several etching techniques have been developed to attain optimal device performance. These are reactive ion etching, time modulated plasma etching, atomic layer etching, and ion beam etching. Sidewall profile, sidewall contamination or damage, redeposition, selectivity, and noncorrosiveness are the main factors to consider while selecting the best etching methods. This paper starts with the fundamentals of MRAM reading, writing, and storing principles and finishes with the current approaches to solve the etch challenges. For etching, the most commonly used magnetic materials such as CoFeB, CoFe, and NiFe are covered in this article.

中文翻译：

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自旋转移扭矩磁性随机存取存储器的干法刻蚀策略：综述

基于自旋的存储器，自旋转移矩磁随机存取存储器 (STT-MRAM)，具有提高高密度存储器系统功率效率的潜力。其理想的特性包括非易失性、快速运行和持久耐用。然而，随着行业提高产量，MRAM 结构的干法蚀刻仍然是一个挑战。在本文中，我们探讨了用于蚀刻 MRAM 结构的蚀刻策略。已经开发了多种蚀刻技术以获得最佳器件性能。这些是反应离子蚀刻、时间调制等离子体蚀刻、原子层蚀刻和离子束蚀刻。侧壁轮廓、侧壁污染或损坏、再沉积、选择性和非腐蚀性是选择最佳蚀刻方法时要考虑的主要因素。本文从 MRAM 读取、写入和存储原理的基础开始，并以解决蚀刻挑战的当前方法结束。对于蚀刻，本文介绍了最常用的磁性材料，如 CoFeB、CoFe 和 NiFe。