Putting pn junctions to work: silicon micro-/nano-mechanical devices based on depletion region actuators and sensors

提出了一个系统研究半导体pn结在微米和纳米尺度上的行为和应用的研究计划。当形成pn结时，来自结的任一侧的多数载流子扩散到相对侧，留下固定在半导体晶格内的电离的受体和供体原子。这在pn结的两侧之间产生库仑体力，其可以由外部电压调制。正如预期的那样，这种力量相当小，在很大程度上被忽视了。采用机械共振允许有效地将这种力放大多达六个数量级，使其适用于许多微型器件的应用。该提案讨论了pn结致动在微米和纳米尺度上优于其他转导机制的优点，并表明pn结致动器具有革命性的微系统设计和应用潜力。 整体的方法，拟议的研究计划加深了我们的理解的pn结致动器的工作原理，同时设计实用的器件设计方法。pn结致动器的现有模型仅适用于最简单的情况。我们将开发现实的设备模型，将使用制造的测试结构和设备的实验数据进行验证。然后，这些模型将被用来设计用于定时，传感和信号处理应用的微器件。将器件尺寸降低到纳米级开辟了许多科学和技术机会。一方面，pn结致动提供了纳米尺度下的有效转导机制，为日常应用的纳米机械器件的发展开辟了道路。另一方面，纳米器件的小尺寸为研究pn结致动器在极端情况下（例如完全耗尽结构）的操作提供了研究机会。掺杂是微电子学中的基本工艺。因此，可以在标准集成电路制造工艺中制造基于pn结致动器的微机械器件，并且如图所示，不需要任何附加步骤。这将允许在任何标准铸造工艺中共同制造微电子和微机械设备。 我的研究团队在微机械谐振器，微传感器，纳米复合材料和微电子电路的设计方面具有专业知识。我们的实验室配备了所有必要的工具，用于微机械和纳米机械的电气特性。此外，SFU拥有两个设备齐全的洁净室，用于制造微型和纳米器件。因此，我们处于一个理想的位置，利用我们的专业知识进行拟议的研究，这将彻底改变该领域。与加拿大和国际研究人员的合作使所涉及的HQP暴露于更广泛的学术和工业界。在该计划的过程中培训的HQP将是领先的研究人员和企业家，他们将把该计划的科学和技术成果转化为微纳米系统领域的新解决方案。 这项研究对该领域产生了直接影响，导致了大量的科学，技术和工业相关成果。通过该计划开发的器件设计方法可以应用于许多新颖的微型和纳米器件的设计，用于不同的应用。考虑到器件设计和制造所需的资源是商业上可获得的，这项开创性的研究将在短期内为加拿大工业和社会带来重大的经济效益。

A research program for the systemic study of the behaviour and applications of semiconductor pn junctions for transduction at micro- and nano-scales is proposed. When a pn junction is formed, majority carriers from either side of the junction diffuse into the opposite side, leaving behind ionised acceptor and donor atoms that are fixed within the semiconductor lattice. This gives rise to a Coulombic body force between the two sides of a pn junction, which can be modulated by an external voltage. As expected, this force is rather small and has been largely ignored. Employing mechanical resonance allows for effective amplification of this force by as much as six orders of magnitude, making it suitable for many applications of microdevices. The proposal discusses the advantages of pn junction actuation over other transduction mechanisms at micro- and nano-scales and demonstrates that pn junction actuators present an unexploited potential to revolutionise microsystem design and application. The holistic approach of the proposed research program deepens our understanding of the operating principles of pn junction actuators while devising practical device design methods. Existing models for pn junction actuators are applicable only to the simplest of cases. We will develop realistic device models that will be verified using experimental data from fabricated test structures and devices. The models will then be employed to design microdevices for timing, sensing, and signal processing applications. Lowering the device dimensions to nano-scales opens up many scientific and technical opportunities. On one hand, pn junction actuation provides an efficient transduction mechanism at nano-scales, leading the way to the development of nano-mechanical devices for daily applications. On the other hand, the small dimensions of nano-devices provide research opportunities to study the operation of pn junction actuators at extreme cases such as fully depleted structures. Doping is a basic process in microelectronics. It is therefore possible to fabricate micromechanical devices based on pn junction actuators in standard integrated circuit manufacturing processes, and as is shown, without a need for any additional steps. This will allow for co-fabrication of microelectronic and micromechanical devices in any standard foundry process. My research team has expertise on the design of micromechanical resonators, microsensors, nanocomposite materials, and microelectronic circuits. Our laboratory is equipped with all the necessary tools for the electrical characterisation of the micro- and nano-mechanical. Additionally, SFU houses two fully equipped cleanrooms for the fabrication of micro- and nano-devices. We are therefore in an ideal position to leverage our expertise to conduct the proposed research, which will revolutionise the field. Collaborations with Canadian and international researchers exposes the involved HQP to the wider academic and industrial community. The HQP trained over the course of this program will be the leading researchers and entrepreneurs who will transform the scientific and technological achievements of this program into novel solutions in the area of micro- and nano-systems. This research has an immediate impact on the field leading to substantial scientific, technical, and industrially relevant outcomes. Device design methodologies developed through this program can be applied to the design of numerous novel micro- and nano-devices for different applications. Considering that the required resources for device design and fabrication are commercially available, this pioneering research will result in significant economic benefit to the Canadian industry and society in the near term.