Principal Component Analysis (PCA)-Assisted Time-of-Flight Secondary-Ion Mass Spectrometry (ToF-SIMS): A Versatile Method for the Investigation of Self-Assembled Monolayers and Multilayers as Precursors for the Bottom-Up Approach of Nanoscaled Devices

ABSTRACT: The production of high-quality self-assembled monolayers (SAMs) followed by layer-by-layer (LbL) self-assembly of macrocycles is essential for nanotechnology appli-cations based on functional surface films. To help interpret the large amount of data generated by a standard ToF-SIMS mea-surement, principal component analysis (PCA) was used. For two examples, the advantages of a combination of ToF-SIMS and PCA for quality control and for the optimization of layer-by-layer self-assembly are shown. The first example investi-gates how different cleaning methods influence the quality of SAM template formation. The second example focuses on the LbL self-assembly of macrocycles and the corresponding stepwise surface modification. One objective of modern nanotechnology is the miniatur-ization of devices with function in order to increase performance while improving energy efficiency. In this context