Crystal with Metal-Insulator Transition by Plasma Processing Technique and Its Application to Switching Devices

等离子体加工技术金属-绝缘体转变晶体及其在开关器件中的应用

• 批准号: 18540495
• 负责人: OKIMURA Kunio
• 金额: $ 2.31万
• 依托单位: Tokai University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 2006
• 资助国家: 日本
• 起止时间: 2006 至 2007
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-18540495/
• 关键词: vanadium dioxide; ICP-assisted sputtering; epitaxial growth; metal-insulator transition; resistive change; switching phenomenon; planer structure; stoichiometry; ププラズマプロセス; ICP支援スパッタ装置

In this project, we deposited vanadium dioxide (V0_2) films on Al_2O_3 substrates with metal-insulator transition (MIT) by using inductively coupled plasma (ICP)-assisted sputtering technique. In addition, we tried to fabricate a new switching device utilizing VO_2 film with MIT.First, we found that by selecting oxygen flow rate proper value compared to flow rate of Ar gas we can deposit stoichiometric film with MIT. Films under adequate conditions revealed MIT with three orders change in resistivity at temperature around 340 K. It was shown that this MIT is caused by crystalline structural transition from monoclinic phase to tetragonal phase through XRD analyses.Next, we fabricated a device of VO_2 with two terminal metal electrodes. We observed current jump phenomena by applying voltage to this device. We call this electric field-induced metal-insulator transition. When we decreased gap length between the two electrodes, threshold voltage that can trigger the electric field-induced MIT decreased. Thus we can control resistance change in this device by changing electrodes gap length.Finally, we fabricated two kinds of planar type devices with dimensions of the electrode gap of 5 μm and the electrode of 1500 μm and 10 μm /10 μm (electrodes gap /electrode width). In these devices, we observed fast resistance change phenomena within 200 ns. Low threshold voltage of 2 V was achieved in the former device, while large resistance ratio was achieved in the latter.Switching phenomena revealed in this project offer great interests not only in applications of VO_2 based planar device to functional electronic devices such as switching and memory devices but also in discussion on physical mechanism of switching phenomenon in oxide material with strong correlation.

在这个项目中，我们通过使用电感耦合的等离子体（ICP）辅助溅射技术，将二氧化钒（V0_2）膜沉积在AL_2O_3底物上。此外，我们尝试使用使用MIT的VO_2膜来制造一种新的开关设备。首先，我们发现，与AR气体的流量相比，通过选择氧气流量应适当的值，我们可以将化学计量膜与MIT沉积。在适当条件下的薄膜显示，MIT在温度下在340 K左右的温度下发生了三个阶的电阻变化。这表明该MIT是由从单斜相结构过渡到通过XRD Analyses的晶体结构过渡引起的。Next，我们用两个终端金属电气来制造VO_2的设备。我们通过在该设备上施加电压来观察当前的跳跃现象。我们称这种电场诱导的金属胰蛋白过渡。当我们改善两个电子之间的间隙长度时，可以触发电场引起的MIT的阈值电压减少。我们可以通过改变电子间隙的长度来控制该设备中的电阻变化。在本文中，我们制造了两种平面型设备，具有5μm的电极间隙的尺寸和1500μm和10μm /10μm的电极（电极间隙 /电极宽度）。在这些设备中，我们观察到200 ns之内的快速抗性变化现象。在以前的设备中达到了2 V的低阈值电压，而在后者中达到了较大的阻力比。在该项目中揭示的开关现象不仅在基于VO_2的平面设备对功能电子设备的应用中提供了极大的兴趣，例如切换和内存设备等功能电子设备，而且在具有强大氧化物材料的切换现象的讨论中，还提供了对氧化现象的讨论。

项目成果

Growth of V0_2 films with metal-insulator transition on silicon substrates in inductively coupled plasma -assisted sputtering

硅衬底上电感耦合等离子体辅助溅射生长具有金属-绝缘体转变的V0_2薄膜

• 发表时间: 2007
• 期刊: Thin Solid Films Vol. 515
• 作者: Kunio;Okimura;N.;Kubo
• 通讯作者: Kubo

Growth of VO_2 films with metal-insulator transition on silicon substrates in inductively coupled plasma-assisted sputtering

硅衬底上电感耦合等离子体辅助溅射生长具有金属-绝缘体转变的VO_2薄膜

• 发表时间: 2007
• 期刊: Thin Solid Films Vol.515
• 作者: K.Okimura;N.Kubo
• 通讯作者: N.Kubo

X-ray Diffraction Study on Electric field induced Metal-Insulator Transition of Vanadium Dioxide Films on Sapphire Substrate Prepared by Reactive Sputtering

反应溅射蓝宝石衬底上二氧化钒薄膜电场诱导金属-绝缘体转变的X射线衍射研究

• 发表时间: 2006
• 作者: Ezreena;Mohamad;Yusuke Sasakawa;Yusuke Nihei;Kunio;Okimura;Jun Takayama and Kunio Okimura;Yusuke Sasakawa and Kunio Okimura
• 通讯作者: Yusuke Sasakawa and Kunio Okimura

Growth of VO_2 films wtih metal-insulator transition on silicon substrates in inductively coupled plasma-assisted sputtering

电感耦合等离子体辅助溅射硅衬底上金属-绝缘体转变VO_2薄膜的生长

• 发表时间: 2007
• 期刊: Thin Solid Films Vol.515
• 作者: M.Murakami;M.M.Basko;Kunio Okimura and N.Kubo
• 通讯作者: Kunio Okimura and N.Kubo

Expitaxial Growth of Conductive Anatase TiO_2:Nb Films on SrTiO_3 Substrate by Reactive Sputtering

反应溅射法在SrTiO_3基底上外延生长导电锐钛矿TiO_2:Nb薄膜

• 发表时间: 2006
• 作者: Ezreena;Mohamad;Yusuke Sasakawa;Yusuke Nihei;Kunio;Okimura;Jun Takayama and Kunio Okimura
• 通讯作者: Jun Takayama and Kunio Okimura