Poly(methyl methacrylate) (PMMA) is used in the semiconductor industry as a model positive-tone extreme ultraviolet (EUV) photoresist. Many of these photoresists used commercially suffer from inherently low EUV sensitivity. This issue can be mitigated by incorporating high-Z elements into the organic polymer; however, a uniform distribution of these elements in the hybridized resist is of utmost importance. In this study, PMMA thin films spin-coated on silicon substrates were exposed to varying amounts of InOx (0, 1, 2, and 4 cycles) using vapor-phase infiltration. The molecular uniformity of the organic-inorganic photoresists was examined by nanoprojectile secondary ion mass spectrometry. The primary ion impacts (106–107), separated in time and space, produce mass spectra from each individual impact. The secondary ions were mass analyzed via time-of-flight.
The growing attention on sustainable development has driven the design and fabrication of low-cost, environmentally friendly, and catalytically active multifunctional materials for real-world end-uses. In this context, the present work focuses on nanocomposite specimens based on graphitic carbon nitride (gCN) and highly dispersed CuFe2O4/NiFe2O4 nanoaggregates. The target systems, obtained via electrophoretic deposition of gCN on carbon cloth substrates followed by functionalization with ternary oxides by means of radio frequency-sputtering, have been subjected to a detailed x-ray photoelectron spectroscopy analysis. The present contribution comprises both wide-scan spectra and high-resolution C 1s, N 1s, O 1s, Cu 2p, Ni 2p, and Fe 2p core level peaks. The data presented and discussed herein offer a thorough picture on the chemical features of the target materials, of key importance for their eventual photo/electrocatalytic applications in pollutant degradation and clean energy production.
Understanding the structure, functions, and interactions of biomolecules is crucial for advances in medicine, biological research, biotechnology, and biomimetic surface engineering. Time-of-flight secondary ion mass spectrometry is a powerful analytical method to explore molecular and structural properties of biomolecules in a wide variety of contexts. Here, we provide reference spectra for cholesterol, an essential, multifunctional steroid lipid ubiquitous in mammalian cells. Spectra were acquired in positive and negative polarity on spin-coated cholesterol layers using a 30 kV Bi3++ primary ion beam.
Polymethylmethacrylate (PMMA) is a positive tone photoresist, which undergoes chain scission under extreme ultraviolet exposure and is often used as a model photoresist for mechanistic studies due to its simplicity. Nano projectile secondary ion mass spectrometry (NP-SIMS) can be used to gain chemical information about the surface composition of a sample. NP-SIMS involves the bombardment of the sample surface with primary ions and the collection of the ejected secondary ions. The primary ions, Au4004+, are separated in time and space, and this enables the analysis of the secondary ions from each individual impact. Thin films (≈25 nm thick) of spin-cast PMMA of different molecular weights (35, 200, 495, and 950 kDa) on the silicon substrate were investigated regarding postincident fragmentation patterns. Three circular areas of 125 μm diameter were analyzed, and a total of 1–1.5 × 106 spectra were taken for each sample.
X-ray photoelectron spectroscopy was used to analyze an authentic sample of Ru3(CO)12. Measurements were made of Ru3(CO)12 both as a powder and as a thin film on Au. The samples were held at 190 K to avoid sublimation during measurements. The Ru 3d5/2 peak was measured to be 282.2 eV and 281.7 eV for the powder and thin film samples, respectively. The C 1s peak for the major C≡O was measured to be 288.0 eV and 287.4 eV for the powder and evaporated film samples, respectively.
