Triple-Beam Focussed-Ion-Beam Microscope

三束聚焦离子束显微镜

• 批准号: EP/F019564/1
• 负责人: Malcolm Grant
• 金额: $ 39.22万
• 依托单位: University College London
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2008
• 资助国家: 英国
• 起止时间: 2008 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=EP%2FF019564%2F1
• 关键词: Triple; Beam; Focussed; Ion; Microscope

The Carl Zeiss XB1540 Cross-Beam focussed-ion-beam microscope at University College London is a unique instrument in a unique location. The instrument is located in a brand new purpose-built class 10,000 cleanroom in the basement level of the London Centre for Nanotechnology in the heart of the capital city. The instrument is equipped not only with an in situ field-emission scanning electron microscope for gallium-free imaging, but also an in situ low-voltage argon-ion-miller for gallium-free nanofabrication. We believe this to be the only such triple-beam combination in the UK.The Achilles' heel of the FIB is that the gallium beam inevitably damages the surface of any milled or imaged sample. The damage consists of both gallium implantation and amorphisation. To some extent this can be ameliorated by using low beam currents (at a cost of longer milling times) and/or low voltages (at a cost of worse imaging contrast). A much more powerful technique is to mill nanoscale features using the conventional FIB and then polish the sample using a broad-beam argon ion miller so as to remove the gallium-implanted and amorphised layer. Not only is argon inert and less mobile than gallium and therefore will do much less damage to the sample, but also the ion energy can be reduced to as low as 30 eV. This greatly reduces the depth of damage done to the sample. When fabricating functional devices and materials using FIB it is important to get some kind of feedback as to when the fabrication is complete. Using the SEM to image the structure is clearly one feedback method, but topology is not the whole story. What one really wants is functional feedback / in other words measuring the device functionality during FIB milling to give feedback to the milling process. For electronic devices this can be done straightforwardly by using electrical connections to the device. Many functional nanoelectronic devices, however, only work at low temperatures / examples include most spintronic, ferroelectric, qubit, multiferroic and superconducting devices.At UCL we have therefore installed a liquid-helium-cooled sample holder with multiple feedthroughs for electrical measurements. This has allowed us to measure in real-time the current-voltage characteristics of superconducting devices as they are being fabricated by FIB.As a result of both the unrivalled performance of the XB1540 FIB and these two unique experimental capabilities, we believe that the UK academic community in materials science, the physical sciences and the life sciences will benefit greatly from access to this instrument.

伦敦大学学院的卡尔·蔡司XB1540十字束聚焦离子束显微镜是一台位于独特位置的独特仪器。该仪器位于伦敦市中心伦敦纳米技术中心地下室的一个全新的10,000级专用洁净室中。该仪器不仅配备了用于无镓成像的原位场发射扫描电子显微镜，还配备了用于无镓纳米加工的原位低电压Ar-Ion-Miller。我们认为这是英国唯一这样的三光束组合。FIB的致命弱点是，镓光束不可避免地会损坏任何被碾磨或成像的样品的表面。损伤包括镓注入和非晶化。在某种程度上，这可以通过使用低束流(以较长的研磨时间为代价)和/或低电压(以较差的成像对比度为代价)来改善。一种更强大的技术是使用传统的FIB来研磨纳米级的特征，然后使用宽束Ar离子磨光机抛光样品，以去除注镓和非晶化层。Ar不仅是惰性的，流动性比镓小，因此对样品的损害要小得多，而且离子能量可以降低到低至30 eV。这极大地减少了对样品造成的损伤深度。当使用FIB制造功能器件和材料时，获得关于何时完成制造的某种反馈是很重要的。使用扫描电子显微镜对结构进行成像显然是一种反馈方法，但拓扑并不是整个故事的全部。人们真正想要的是功能反馈/换句话说，在FIB铣削过程中测量设备的功能，以便为铣削过程提供反馈。对于电子设备，这可以通过使用到设备的电连接直接完成。然而，许多功能纳米电子器件只能在低温下工作，例如大多数自旋电子器件、铁电器件、量子比特器件、多铁性器件和超导器件。因此，在伦敦大学学院，我们安装了具有多条馈线的液氦冷却样品保持器，用于电学测量。这使得我们能够实时测量FIB正在制造的超导设备的电流-电压特性。由于XB1540 FIB无与伦比的性能和这两种独特的实验能力，我们相信英国材料科学、物理科学和生命科学的学术界将从使用该仪器中受益匪浅。