Compensation of thermal drift effects in atomic force microscopy using probabilistic state estimation

使用概率状态估计补偿原子力显微镜中的热漂移效应

• 批准号: 243221359
• 负责人: Professor Dr.-Ing. Sergej Fatikow
• 金额: --
• 依托单位: Abteilung Mikrorobotik und Regelungstechnik
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2013
• 资助国家: 德国
• 起止时间: 2012-12-31 至 2016-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/243221359?language=en
• 关键词: Compensation; thermal; drift; effects; atomic

Since more than two decades, the atomic force microscope (AFM) represents an essential instrument in various disciplines covering life science, biology, material science, semiconductor industries, and micro- and nanotechnology in general. It has revolutionized surface analysis by providing high-resolution visualization of structures at micro-, nano-, and atomic scales. While AFM was first only used for imaging the topography of a sample, different operation modes evolved over time including electrical, magnetic, and chemical measurements. The need for novel lithographic methods providing higher resolution than conventional lithographic processes and enabling to process new materials (e.g. biomaterials) have motivated research in the domain of AFM-based lithography. Intense research has also been carried out on the manipulation of individual micro-/nanoentities with the AFM tip. Promising potential applications of such AFM-based assembly are e.g. prototyping of novel nanoelectronic devices and systems based on nanomaterials such as CNTs, DNA, single-graphene layers, nanowires, etc. A problem that is affecting almost every application area of AFM is the presence of thermal drift induced. Thermal drift originates from small changes in temperature and differences in the coefficient of thermal expansion of the different components of the AFM (or SPM in general). This results in an unknown, time-variant displacement of the probe relative to the sample in all three dimensions. This motion is generally slow, but it is causing distortions in images and lithographic processes, falsifying spectroscopy results, and compromising the success of nanomanipulations. In the proposed project our major objective is the development of a flexible drift compensation system applicable in the context of imaging, spectroscopy as well as nanomanipulation tasks. The developed methods should allow for an active compensation of thermal drift during image acquisition and manipulation in real-time without any prior knowledge of the sample properties or drift state. Moreover, it should compensate drift in all three dimensions thus not limiting the field of application. To reach these objectives a probabilistic algorithm will be developed incorporating non-raster scanning methods, generally valid models describing AFM topography data as well as a probabilistic model describing drift. The algorithm will be based on Bayesian filtering to incorporate the uncertainties introduced by inaccurate models. The system will be experimentally validated on different systems using a custom-made AFM control architecture in the context of AFM-based automated manipulation of different nanoobjects.

自二十多年以来，原子力显微镜（AFM）代表了涵盖生命科学，生物学，材料科学，半导体行业以及微技术的各种学科中的重要工具。它通过在微型，纳米和原子尺度上提供高分辨率的结构可视化来彻底改变了表面分析。虽然AFM首先仅用于对样品的地形进行成像，但随着时间的推移，不同的操作模式随时间发展，包括电气，磁性和化学测量。比传统的光刻过程和能够处理新材料（例如生物材料）的新型光刻方法的需求具有更高的分辨率。还对用AFM尖端操纵单个微/纳米含量进行了激烈的研究。这种基于AFM的组装的有希望的潜在应用是例如基于纳米材料（例如CNT，DNA，单格烯层，纳米线等）基于纳米材料的新型纳米电器设备和系统的原型。热漂移源于温度的较小变化和AFM不同组分（或SPM）不同组件的热膨胀系数的差异。这会导致探针相对于样品在所有三个维度中的未知时变化的位移。这种运动通常很慢，但是正在引起图像和光刻过程中的扭曲，伪造光谱结果以及损害纳米流动的成功。在拟议的项目中，我们的主要目标是开发适用于成像，光谱和纳米操纵任务的灵活漂移补偿系统。开发的方法应允许在图像采集和实时操纵过程中对热漂移的积极补偿，而不必先验地了解样品特性或漂移状态。此外，它应补偿所有三个维度的漂移，因此不会限制应用领域。为了达到这些目标，将开发出概率算法，并结合非悬挂扫描方法，通常描述AFM地形数据以及描述漂移的概率模型的有效模型。该算法将基于贝叶斯过滤，以结合不准确模型引入的不确定性。在基于AFM的自动操纵不同纳米对象的背景下，将使用定制的AFM控制体系结构在不同系统上实验验证该系统。