磁随机存取存储器:专利视角下的产业化趋势

Magnetic random access memory: Commercialization trend from the perspective of patents

磁随机存取存储器,作为未来最有希望代替现有随机存储器的新型数据非易失性存储器技术之一,具有高速度、高密度、非易失性、长寿命、低功耗、抗辐射等优势,未来产业价值巨大、应用前景非常广阔,成为美国、欧洲、日本和韩国等高端芯片制造强国/地区竞相抢占的战略新高地.本文通过大数据方法和对该新兴技术领域的全球专利战略分析,从专利的视角分析了该新兴技术领域的研发状态、产业化趋势及未来市场竞争格局.

As one of the most promising new nonvolatile memory technologies in the future, magnetic random access memory（MRAM） can address a wide range of potential memory applications, potentially worth thousands of billions of dollars with the substantial advantages of nonvolatility, radiation hardness, unlimited endurance, high speed, high density and low power consumption, attracting worldwide investments, especially from the United States, Europe, Japan and South Korea. From the perspective of patents, the commercialization trend and competitiveness of MRAM emerging industry are explored based on the analysis of global patent application data in this technology field. The first commercially available MRAM device with a storage capacity of 4 Mbit was actually realized in 2006. Current 16 Mbit MRAM devices based on magnetic field-driven switching have been applied on a small scale in niche areas ranging from aerospace to industrial and automotive systems. The further commercial development of MRAM with a storage capacity of 1 Gbit has now become the research goal. The scalability embodied in switching using the spin torque transfer（STT） effect has transformed the prospects for MRAM commercialization. Novel designs based on STT current switching can be expected to open a new route for fabricating scalable MRAM devices with high density, high performance, but low power consumption. Although STT-MRAM is only just beginning to be commercialized, the rapid increase of patent applications in this domain signals the desire for commercialization. Most recently, novel MRAM devices based on the spin orbit coupling（SOC） effects such as spin Hall effect, Rashba effect, Dzyaloshinskii-Moriya interaction（DMI）, etc. are emerging, and a highly dynamic and competitive market in the near future will be expected. Patents data in MRAM technology field were retrieved from the Derwent Innovations Index（DII） patents database including the Derwent World Patents Index（DWPI） and Derwent Patents Citation Index（DPCI） databases. The data set contains a total of 6136 patent records with the retrieval date of 2015-11-22, and data retrieval keywords involving MRA）, STT-MRAM, etc. as well as magnetic memory/storage utilizing spin effects. Such patents data analysis tools as Thomson Data Analyzer（TDA） and Patent Map developed by Thomson Reuters, Innography developed by Dialog, etc., were applied. The ten countries/regions with the most patent applications in MRAM are US, Japan, Korea, China, Europe, Germany, France, Canada, Singapore and UK. The ten companies with the most patent applications in MRAM are Samsung Electronics, Toshiba, Hynix Semiconductor, Micron Technology, IBM, Renesas Technology, Hewlett Packard, Sony, NEC and Seagate. The research hotspots of patents in MRAM are illustrated by patent map, and the differences of technology layout for the major research countries such as US, Japan, Korea, China, and Europe are also analyzed. The valuation of Chinese granted patents towards their significance of technologies in MRAM as well as in spintronic devices are considered.