Quantum-mechanical device concepts including ultra-thin functional ALD-films for terahertz applications

太赫兹频率范围目前是众多技术应用的核心战略研究领域之一。与以前的方法相反，这里提出的概念研究倾向于基于量子力学设备的频率产生。该项目的主要目的是对生产这种量子力学设备的相关因素有一个基本的了解。由于其中包含的薄膜仅跨越几个原子层，因此除了器件演示器的整体特性外，还将考虑单个层的功能材料特性和相邻层之间的界面行为。因此，这个项目不关注仅仅生产一个完整的晶体管和它的电气评估。相反，这项研究服务将集中在三个基本方面，这对太赫兹应用中量子力学器件的功能至关重要：首先，超薄功能层的初始生长将在原子层沉积（ALD）过程的精确位置（原位）和实时进行研究。为此，真空簇工具以全球独特的方式结合了各种直接和间接表面分析方法（光电子能谱，扫描探针显微镜，椭偏光，质谱），从而提供了非常详细的深入了解ALD生长行为的亚原子水平。其次，将合成超薄石墨层，并使用代表隧道热电子晶体管核心的二极管状装置来表征其相对于热电子的垂直透明度。第三，在首次实现的基于器件的工艺路线的基础上，研究超薄ALD薄膜与超薄石墨层的相互作用。

The terahertz frequency range currently constitutes one of the central strategic research fields for numerous technical applications. In contrast to previous approaches, the here-proposed concept study favors a frequency generation based on quantum-mechanical devices. The main aim of thisproject is to obtain a fundamental understanding of the relevant factors in the production of such quantum-mechanical devices. As the films included therein span only a few atomic layers, the functional material properties of the individual layers and the behavior of interfaces between adjacentlayers will be considered in addition to the characteristics of a device demonstrator in its entirety. So, this project does not focus on the mere production of a complete transistor and its electrical evaluation. Instead, this research service will concentrate on three basic aspects that are crucial forthe functionality of quantum-mechanical devices in terahertz applications: First, the initial growth of ultra-thin functional layers will be investigated at exactly the place (in situ) and in real-time of the atomic layer deposition (ALD) processes. For this purpose, a vacuum cluster tool combines variousdirect and indirect surface analysis methods (photoelectron spectroscopy, scanning probe microscopy, ellipsometry, mass spectrometry) in a worldwide unique manner and thus provides an extraordinarily detailed insight into the ALD growth actions down to the sub-atomic level. Second, ultrathin graphite layers will be synthesized and their vertical transparency with respect to hot electrons will be characterized using a diode-like device which represents the core of a tunneling hot electron transistor. Third, the interaction of ultra-thin ALD films with the ultrathin graphite layer will be studied on the basis of a device-based process route implemented for the first time.