{'fraction_non_alphanumeric': 0.02504268639726807, 'fraction_numerical': 0.006260671599317018, 'mean_word_length': 4.959322033898305, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
Application of a gas-injection system during the FIB-TOF-SIMS analysis - influence of water and fluorine gases on secondary ion signals and sputtering rates.

Combining a Gas-Injection System (GIS) with the Focused Ion Beam (FIB) has a broad scope of applications in sample preparation such as protective layer deposition, increasing material sputtering rates and reducing FIB-related artefacts. On the other hand injecting certain specific gases during a Time-of-Flight Secondary Ion Mass Spectrometry (TOF-SIMS) analysis can significantly increase element ionization probability and, therefore, improve the quality of 3D representation of a sample elemental structure. In this work, for the first time the potential of GIS for enhancing secondary ion signals acquired using a TOF detector incorporated into a commercial Ga+ FIB-SEM (Focused Ion Beam combined with Scanning Electron Microscope) instrument is presented. The depth profiles of pure metals (100 nm thick thin films of Cu, Zr, Ag and W) were acquired at ambient vacuum conditions as well as under an exposure to water and fluorine gases. The influence of supplementary gases on the ion yields and sputtering rates were studied. Simulations were performed to assess the local gas pressure at the location of FIB-TOF-SIMS analysis. The highest enhancement of ionization probability was achieved in the case of the Cu thin film (10 times during water co-injection and 510 times when using a fluorine gas). Regarding the sputtering rates, the response of Zr to effect of the gases was the strongest. Comparing to a standard background pressure measurements, this thin film was milled around 6 times faster under the exposure to a water vapor and over 2 times faster when fluorine gas was supplied.