NIRT: Nanoscale Organic Circuits and Sensors

本提案是对NSF 01-157 NIRT类纳米科学与工程倡议的响应。它的重点是基于有机半导体的纳米级晶体管，这是一个特别重要的活动领域，有许多有待了解和发现。有机纳米晶体管利用了从分子自组装到先进纳米光刻的各种制造方法。这一点，再加上在设计和合成一系列半导体材料方面的相当大的灵活性，提供了这样的装置有一天可能成为新一代电子电路的元件的希望。在分子的空间尺度上限制和操纵电荷的能力是分子电子学的一个重要优势。拟议的项目旨在将自组装和先进的纳米光刻技术结合起来，实现两个系列的纳米级晶体管器件，从而能够对这些器件作为电子电路中的元件进行系统评估。这项研究的关键是在有机纳米晶体管中使用先进的高k介电材料。这将降低器件的工作电压，并允许感应非常大的电荷密度，这反过来又被证明在电荷传输和相关应用中开辟了新的领域。该项目将涉及用常规方法和扫描探头方法对设备进行表征。此外，它还将涉及有机半导体和栅绝缘体之间界面的广泛表征，以及横向分辨率低至1 nm的自组装有机层的形态表征。近年来，大面积有机晶体管被证明具有独特的性质，如化学传感和发光。这项研究将首次详细研究纳米晶体管的化学传感方面，这项研究将结合半导体的化学设计和受体基团，以结合特定的分析物，并详细表征半导体和分析物之间相互作用的化学性质。在将要探索的纳米级晶体管的其他特性中，还有超导电性。最近在大面积聚合物晶体管中观察到了超导电性，这类晶体管的建议应用包括量子信息处理。最后，提出了一种有机纳米晶体管电路与硅电路兼容的电路制作新方法。该架构允许(原则上)在硅电路和有机电路之间共享功能。制造方案的关键方面是使用倒置方法来制造有机电路，在该方法中，首先定义互连，然后是栅级，最后是源漏电平。因此，脆弱的分子材料不会暴露在恶劣的加工环境中。

AbstractThis proposal was received in response to Nanoscale Science and Engineering initiative, NSF 01-157, category NIRT. It focuses on organic semiconductor based nanoscale transistors, a particularly important area of activity where much remains to be understood and discovered. Organic nanoscale transistors make use of fabrication approaches ranging from molecular self-assembly to advanced nanolithography. This, together with the considerable flexibility in designing and synthesizing a range of semiconducting materials offers hope that such devices may one day be components in a new generation of electronic circuits. The ability to confine and manipulate electric charges on the spatial scale of a molecule is an important advantage for molecular electronics. The proposed project aims at combining self-assembly and advanced nanolithography to realize two families of nanoscale transistor devices that will enable the systematic evaluation of these devices as components in electronic circuits. Crucial to the study is the use of advanced high k dielectrics in organic nano-transistors. This will lower the operating voltage of the devices as well as permit the induction of very large densities of charge, which in turn has been shown to open up new domains in charge transport with associated applications. The project will involve device characterization by conventional methods as well as by scanning probe methods. Additionally, it will involve extensive characterization of interfaces between organic semiconductors and gate insulators, and morphological characterization of self-assembled organic layers with a lateral resolution down to 1 nm. Large-area organic transistors have been shown in the recent past to have unique properties such as chemical sensing and light-emission. The chemical sensing aspects of nanotransistors will be examined in detail for the first time This study will combine chemical design of semiconductors with receptor groups to bind specific analytes with detailed characterization of the chemical nature of the interaction between semiconductor and analyte. Among other properties of nanoscale transistors that will be explored is superconductivity. Superconductivity has been observed recently in large-area polymer transistors and among the suggested applications of such transistors includes quantum information processing. Finally, a new approach to fabricate circuits is proposed in which the organic nano-transistor circuitry is compatible with Si-circuitry. This architecture permits (in principle) the sharing of functionality between the Si circuitry and the organic circuitry. The key aspect of the fabrication scheme is the use of an up-side down approach to fabricate organic circuitry, in which the interconnects are defined first followed by the gate level and finally the source-drain level. Thus the fragile molecular materials are not exposed to harsh processing environments.