Deep depth profiling using gas cluster secondary ion mass spectrometry: Micrometer topography development and effects on depth resolution

Abstract

Secondary ion mass spectrometry using the argon cluster primary ion beam enables molecular compositional depth profiling of organic thin films with minimal loss of chemical information or changes in sputter rate. However, for depth profiles of thicker organic films (>10 μm of sputtered depth), we have observed the rapid formation of micron‐scale topography in the shape of pillars that significantly affect both the linearity of the sputter yield and depth resolution. To minimize distortions in the 3D reconstruction of the sample due to this topography, a stepwise, staggered sample rotation was employed. By using polymer spheres embedded in an organic film, it was possible to measure the depth resolution at the film‐sphere interface as a function of sputtered depth and observe when possible distortions in the 3D image occurred. In this way, it was possible to quantitatively measure the effect of micron‐scale topography and sample rotation on the quality of the depth profile.

Applications of spatially resolved omics in the field of endocrine tumors

“…There are various types of commercially available primary ion beams, including monatomic (Au + , Cs + and O - ) and polyatomic ion beams ( ), liquid metal ion guns (LMIGs) ( and ) and gas cluster ion beams (GCIBs) ( , (CO 2 and ( 101 – 106 ). The sensitivity and spatial resolution of SIMS-MSI are influenced by the type, the energy and the focusing spot size of the primary ion beams.…”

Atomic spectrometry update: review of advances in the analysis of metals, chemicals and materials

“…The second paper, by Muramoto and Graham, also used a 20 keV Ar gas cluster beam for sputtering and a Bi 3 + beam for analysis. 209 Both ion sources struck the sample at an angle of 45°, with a typical cycle comprising one scan of analysis, 10 scans of sputtering and 2 s of charge compensation. Three thin film types were analysed: gelatin, pullulan and polyethylene terephthalate (PET).…”

“…Analysis was achieved using ICP-MS with an assortment of internal standards introduced as a mixture on-line rather than being spiked into individual samples. The internal standards used were 45 Sc for those elements with a mass up to and including 59 Co, 72 Ge for the analytes 62 Ni to 95 Mo, 125 Te for 101 Ru to 137 Ba, 175 Lu for the analytes 189 Os to 197 Au and 209 Bi for analytes with a higher mass. Any polyatomic interferences were removed through the introduction of helium at a ow rate of 5 mL min −1 into the collision/reaction chamber.…”

“…Two papers have used SIMS employing gas cluster primary ion beams to analyse thin (20–50 nm) extreme ultraviolet photoresist films 208 and organic thin films. 209 The use of gas cluster primary ion beams causes less sputter damage to organic-based films. In the first example, Spampinato et al used two SIMS instruments to analyse the photoresists.…”