Substrate effects on the surface topography of evaporated gold films — a scanning tunnelling microscopy investigation

Abstract

Direct observation of surface roughness on metal films is a longstanding problem in thin film characte~tion.In this work the high quality of scanning tunnelhng microscopy (STM) was used for investigation of evaporated gold films. A scanning tunnel&g microscope able to scan areas up to 0.8 x 0.8 pm with high reproducibility is presented. The topography of 80 nm thick gold films grown under identical evaporation conditions was investigated as a function of the selected substrate material (Corning glass, silicon, NaCl, mica and highly oriented pyrolitic graphite (HOPG)). The incipient growth mechanism on the substrate is the primary reason for the surface roughness. Tbe real space images of the surface topography correlate very well with knowledge achieved from former growth experiments given in the literature. Moreover, very flat gold surfaces on HOPG allowed the observation of atomic corrugations in air environments.

Oriented, Active Escherichia coli RNA Polymerase: An Atomic Force Microscope Study

“…1. Previously, much work has been carried out to make very flat evaporated gold films on mica (Chidsey et al, 1988;Manne et al, 1990;Putnam et al, 1989;Vancea et al, 1989). To make gold films on mica that are suitable for biological samples studied by AFM the substrate temperature and evaporation conditions must be rigorously controlled.…”

Low-Temperature Adsorption of Carbon Monoxide on Gold Surfaces: IR Spectroscopy Uncovers Different Adsorption States on Pristine and Rough Au(111)

“…It is noteworthy that evaporation of only 0.33 ML of additional gold on the pristine Au(111) surface(thus on the perfect substrate for epitaxial growth) at room temperature and at extremely low deposition rate leads to strong deviations from the smooth surface. This explains the difficulties to prepare atomically smooth gold films at room temperature [42][43][44]. Even after annealing to 473 K for 5 min, significantly more defect-like places are observed as monitored by the enhanced intensity of ν r as compared to the pristine Au(111) surface.We also have evaluated the absorbances on all surfaces in the ranges of ν r (2020-2127 cm −1 ), ν p (2127-2139.3 cm −1 ) and ν c (2139.3-2160 cm −1 ) by integrating dω [y 0 (ω) − R(ω)/R 0 (ω)] over the indicated wavenumber ranges, respectively.…”

Development of an inexpensive Raman-compatible substrate for the construction of a microarray screening platform

“…Then, the substrates were individually dried with filtered compressed air and placed in a desiccator for storage. Next, a 5-nm-thick chromium adhesion layer [25] was deposited following a 50-nm-thick gold layer [22,26] using a thermal evaporator (Nano36, Kurt J. Lesker Company) equipped with a quartz crystal to monitor the deposition thickness. Finally, the gold-coated substrates were transported to a clean room for deposition of a final 100-nm-thick SiO 2 layer [23,26] by plasma enhanced chemical vapor deposition (Minilock-Orion PECVD, Trion Technology, rate = 35 nm/min, time = 180 s).…”