Fast and reliable multilevel phase-change memory for practical application

2016 Fiscal Year Final Research Report

• Project/Area Number: 24686042
• Research Category: Grant-in-Aid for Young Scientists (A)
• Allocation Type: Partial Multi-year Fund
• Research Field: Electron device/Electronic equipment
• Research Institution: Gunma University
• Principal Investigator: Yin You 群馬大学, 理工学研究科, 助教 (10520124)
• Research Collaborator: HOSAKA Sumio ; ZHANG Yulong ; IWASHITA Shota
• Project Period (FY): 2012-04-01 – 2017-03-31
• Keywords: 不揮発性メモリ / 多値記録 / カルコゲナイド / 制御 / 結晶化 / アモルファス化 / 相変化メモリ / 高速

Outline of Final Research Achievements

We investigated the multilevel storage in phase change memory here. We developed new chalcogenide materials suitable for multilevel storage. By doping N into conventional Sb2Te3, the resistivity gradually drops in a wide range of temperature. This was caused by crystal growth suppression because of the existence of scattered nitrides in the film. 16 resistance levels were demonstrated using a N-doped Sb2Te3 lateral device with a top TiN layer. We also adopted Ge1Sb4Te7 and demonstrated that 27 resistance levels can be obtained using the similar device structure. And cyclability was proved to be possible in this device. GeTe devices exhibited fast speed operation and showed the possibility of multilevel storage. We also investigated how we can obtain the resistance levels using a stair-like programming method. This method was demonstrated that the resistance level can be freely accessible, that is, we can reach any desired resistance levels directly.

Free Research Field

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