Preparation of parallel type high density magnetic random access memory

采用薄膜沉积和微加工技术制备了磁性随机存取存储器（MRAM）原型。由磁阻层（FeCo/Cu/FeCo夹层结构）、上下绝缘层和上下电极丝组成1位模式的MRAM。插入绝缘层是为了使磁阻层与电极之间局部电接触，使读出的电流沿膜面穿过磁阻层，这是有效检测所必需的。利用外部电磁铁进行写入操作，并确认存储操作。在制备MRAM器件的过程中，最重要的技术是微加工。本研究还发明了蠕变基底真空蒸发（VECS）技术，以改进制备工艺。

Prototype of Magnetic Random Access Memory (MRAM) was prepared by using thin film deposition and microfabrication techniques. MRAM of 1 bit pattern was made from magnetoresistive layer (FeCo/Cu/FeCo sandwich structure), upper and lower insulating layers and upper and lower electrode wires. Insulating layers were inserted in order to make partial electric contact between the magnetoresitive layer and electrodes, so that the electric current for read-out runs through the magnetoresistive layer along the film plane, which is necessary for effective detection. Writing operation was carried out with external electromagnet and the memory operation was confirmed.In preparing the MRAM device the most important technique is the microfabrication. Vacuum Evaporation with Creeping Substrate (VECS) technique was also invented in this study, to improve the fabrication technique.