相变材料的干法刻蚀及相变存储器的制备工艺研究

发布时间：2018-05-14 17:12

本文选题：相变存储器 + 电感耦合等离子　；参考：《华中科技大学》2012年硕士论文

【摘要】：相变存储器因具有非易失性、擦写速度快、存储密度高、可靠性高、抗辐射、与CMOS工艺兼容等特点而被业界认为是最有可能取代Flash的下一代存储器。在相变存储器从研究阶段到产业化的发展过程中，，其制备工艺是其中的关键技术之一。稳定可靠的制备工艺才能保证器件的优良性能，高可控性、一致性和重复性的制备工艺也是产业化的必要条件。本文首先研究相变材料的具有高可控性和一致性的干法刻蚀工艺。采用电感耦合等离子技术研究出了适于Ge2Sb2Te5和不同周期的超晶格相变薄膜材料的刻蚀工艺，利用金相显微镜、台阶仪和原子力显微镜等仪器对刻蚀结果的测试和分析显示，得到了较高的刻蚀速率、很好的一致性和良好的刻蚀形貌。本文基于对相变材料的干法刻蚀工艺研究，将其运用到相变存储器的制备工艺中，制备了T型结构的相变存储器单元，并与剥离工艺制备的不同相变材料的T型结构单元对比，比较了两种工艺的特点，总结了其中的难点并提出解决方案。最后进行了相变存储器电学性能研究，测试结果表明，采用刻蚀工艺和剥离工艺制备的存储器单元均实现可逆相变，其中采用电感耦合等离子刻蚀工艺制备的以超晶格薄膜为相变材料的存储器单元相变电压为1.9V，操作电流8μA，最快RESET速度为500ps。相变材料的刻蚀工艺成功应用于相变存储器的制备中，对器件未来的小型化和产业化具有重要意义。
[Abstract]:Phase change memory (PCM) is considered to be the next generation memory which is most likely to replace Flash because of its non-volatile, fast writing speed, high storage density, high reliability, radiation resistance and compatibility with CMOS process. In the development of phase change memory from research stage to industrialization, its preparation process is one of the key technologies. The stable and reliable preparation process can guarantee the good performance of the device, high controllability, consistency and reproducibility are also the necessary conditions for industrialization. In this paper, the dry etching process of phase change materials with high controllability and consistency is studied. The etching process of phase change superlattice films suitable for Ge2Sb2Te5 and different periods was studied by inductively coupled plasma technique. The etching results were measured and analyzed by means of metallographic microscope, step instrument and atomic force microscope. High etching rate, good consistency and good etching morphology were obtained. In this paper, based on the study of dry etching of phase change materials, a phase change memory cell with T structure is prepared by applying it to the fabrication process of phase change memory, and it is compared with the T type structure unit of different phase change materials prepared by stripping process. The characteristics of the two processes are compared, the difficulties are summarized and solutions are put forward. Finally, the electrical properties of phase change memory are studied. The test results show that the memory cells prepared by etching and stripping process can realize reversible phase transition. The phase change voltage of the memory cell prepared by inductively coupled plasma etching is 1.9 V, the operating current is 8 渭 A, and the fastest RESET speed is 500ps. The etching process of phase change materials has been successfully applied to the fabrication of phase change memory, which is of great significance to the miniaturization and industrialization of devices in the future.
【学位授予单位】：华中科技大学
【学位级别】：硕士
【学位授予年份】：2012
【分类号】：TN305.7;TP333

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