Selective Passivation of Electrical Defects in Metal Oxides

金属氧化物中电缺陷的选择性钝化

• 批准号: 288812048
• 负责人: Professor Dr. Gerd-Volker Röschenthaler
• 金额: --
• 依托单位: Department of Physics and Earth Sciences
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2016
• 资助国家: 德国
• 起止时间: 2015-12-31 至 2019-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/288812048?language=en
• 关键词: Selective; Passivation; Electrical; Defects; Metal

In 1962 the first solid state metal oxide gas-sensor was reported. Since then metal oxides gained high importance in the fields of sensors due to their excellent chemo-resistive properties. Since 2004 another fast developing field of application for metal oxides was promoted by Hosono who fabricated the first metal oxide based thin-film transistor (TFT). High mobility even in amorphous and nano-crystalline films, transparency in the visible range and solution processability by cheap deposition technology make the class of material highly interesting for innovative electronic applications, e.g. for transparent and smart displays. The dynamic surface structure of metal oxides serves as big advantage for sensor and catalysis applications but represents the major drawback of the material as active layer in transistors. Logic circuits require high stability and reliability even under long term operation. These criteria turned out to be very challenging in metal oxide transistor application. Especially, a high sensitivity of the electrical devices towards humidity was correlated to the significant instability of device characteristics. The effect becomes even more enhanced by the ultra-thin films and their nanoparticular and amorphous character.Especially in cheap and low temperature processes, which are a prerequisite for wide spread applications, an increased density of impurities is incorporated in the material creating a high number of defect states which act as electrically active sites hampering proper transistor operations. Low temperature (< 200 °C) spray deposited ZnO is possible as a large-area coating process, but exhibits a dramatic performance loss with decreasing temperature. Hence passivation of these active sites is not only necessary to improve device stability significantly but also to reduce the process temperature dramatically while keeping the performance constant. In this project various approaches are followed to selective passivate those defects during and/or after deposition. In this respect, Fluor containing molecules are known for their unique properties, e.g. Teflon towards water. AG Wagner and AG Röschenthaler have already demonstrated exceptional passivation properties offered by specific Fluor containing molecules with respect to metal oxide transistor operations. Focus in this project is to systematically modify functional chemical groups in Fluor containing molecules, which allow to understand their passivation mechanism and to identify superior passivation procedures and strategies for metal oxide transistors.

1962年报道了第一个固态金属氧化物气敏元件。 从那时起，金属氧化物由于其优异的化学电阻特性而在传感器领域获得了高度的重要性。自2004年以来，另一个快速发展的金属氧化物应用领域由细野推动，他制造了第一个金属氧化物薄膜晶体管（TFT）。即使在非晶和纳米晶薄膜中也具有高迁移率，可见光范围内的透明度以及通过廉价沉积技术实现的溶液可加工性使得这类材料对于创新的电子应用非常感兴趣，例如用于透明和智能显示器。金属氧化物的动态表面结构为传感器和催化应用提供了巨大的优势，但代表了该材料作为晶体管活性层的主要缺点。逻辑电路即使在长期工作下也需要高稳定性和可靠性。这些标准在金属氧化物晶体管应用中变得非常具有挑战性。特别是，电气设备对湿度的高灵敏度与设备特性的显著不稳定性相关。特别是在廉价和低温工艺中，这是广泛应用的先决条件，材料中杂质密度的增加会产生大量的缺陷态，这些缺陷态作为电活性位点，阻碍晶体管正常工作。低温（< 200 °C）喷雾沉积ZnO作为大面积涂覆工艺是可能的，但随着温度降低表现出显著的性能损失。因此，这些活性位点的钝化不仅对于显著提高器件稳定性是必要的，而且对于在保持性能恒定的同时显著降低工艺温度也是必要的。在这个项目中，采用各种方法在沉积过程中和/或沉积后选择性钝化这些缺陷。在这方面，含氟分子因其独特的性质而闻名，例如Teflon对水的作用。AG瓦格纳和AG罗旭格已经证明了特殊的含氟分子在金属氧化物晶体管操作方面提供的卓越钝化性能。该项目的重点是系统地修改含氟分子中的功能化学基团，从而了解其钝化机制，并确定金属氧化物晶体管的上级钝化程序和策略。