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Resistive random-access memory (RRAM or ReRAM) is a type of non-volatile (NV) random-access (RAM) computer memory that works by changing the resistance across a dielectric solid-state material often referred to as a memristor. This technology bears some similarities to CBRAM and phase-change memory (PCM). CBRAM involves one electrode providing ions that dissolve readily in an electrolyte material, while PCM involves generating sufficient Joule heating to effect amorphous-to-crystalline or crystalline-to-amorphous phase changes. On the other hand, RRAM involves generating defects in a thin oxide layer, known as oxygen vacancies (oxide bond locations where the oxygen has been removed), which can subsequently charge and drift under an electric field. The motion of oxygen ions and vacancies in the oxide would be analogous to the motion of electrons and holes in a semiconductor. RRAM is currently under development by a number of companies, some of which have filed patent applications claiming various implementations of this technology. RRAM has entered commercialization on an initially limited KB-capacity scale.〔http://www.mouser.tw/new/panasonic/panasonic-mn101l-reram/〕 Although commonly anticipated as a replacement technology for flash memory, the cost benefit and performance benefit of RRAM have not been obvious enough to most companies to proceed with the replacement. A broad range of materials apparently can potentially be used for RRAM. However, the recent discovery〔H-Y. Lee et al., IEDM 2008.〕 that the popular high-κ gate dielectric HfO2 can be used as a low-voltage RRAM has greatly encouraged others to investigate other possibilities. == History == In February 2012 Rambus bought an RRAM company called Unity Semiconductor for $35 million. Panasonic launched an RRAM evaluation kit in May 2012, based on a tantalum oxide 1T1R (1 transistor – 1 resistor) memory cell architecture. In 2013, Crossbar introduced an RRAM prototype as a chip about the size of a postage stamp that could store 1 TB of data. In August 2013, the company claimed that large-scale production of their RRAM chips was scheduled for 2015. The memory structure (Ag/a-Si/Si) closely resembles a silver-based CBRAM. Different forms of RRAM have been disclosed, based on different dielectric materials, spanning from perovskites to transition metal oxides to chalcogenides. Silicon dioxide was shown to exhibit resistive switching as early as 1967, and has recently been revisited. Leon Chua argued that all two-terminal non-volatile memory devices including RRAM should be considered memristors. Stan Williams of HP Labs also argued that RRAM was a memristor. However, others challenged this terminology and the applicability of memristor theory to any physically realizable device is open to question. Whether redox-based resistively switching elements (RRAM) are covered by the current memristor theory is disputed. In 2014 researchers announced a device that used a porous silicon oxide dielectric with no edge structure. In 2010 conductive filament pathways were discovered, leading to the later advance. It can be manufactured at room temperature and has a sub-2V forming voltage, higher on-off ratio, lower power consumption, nine-bit capacity per cell, higher switching speeds and improved endurance.〔(【引用サイトリンク】title=the Foresight Institute » Blog Archive » Nanotechnology-based next generation memory nears mass production )〕 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Resistive random-access memory」の詳細全文を読む スポンサード リンク
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