Investigation of polymer thin films by use of Bi-cluster-ion-supported time of flight secondary ion mass spectrometry

Abstract

The investigation and analysis of polymer thin films with Bi(n)(+), n = 1-7 cluster ions has been demonstrated by means of static secondary ion mass spectrometry (SIMS). The highly specific signal enhancement of these primary ions combined with the individual fragmentation pattern of poly(4-vinylphenol) and poly(methyl methacrylate) is the basic principle for a modified approach of data reduction derived from the well-established g-SIMS procedure. Based on mass spectra, which correspond to different cluster ion sizes, not only a clear distinction between the two polymers is feasible but also a further simplification of the data can be demonstrated. It has been successfully proven that characteristic polymer-relevant species can be refined out of the large amount of unspecific and highly fragmented secondary ions, which are usually present in SIMS spectra. Therefore, a more precise and direct interpretation of complex organic fragments becomes feasible, which consequently enables the investigation of even more sophisticated samples.

Investigation of 1‐butyl‐3‐methylimidazolium bis(trifluoromethylsulfonyl)imide under Binx+ cluster ion bombardment

“…[14] The difference between the measured ion currents was at maximum ±5%, which is in good agreement with previously published data. [12,13,14] Typical operation conditions and beam performance are summarized in Table 4. Primary ion energy was 25 keV for single charged ion clusters, and 50 keV for double charged ion clusters.…”

“…Polyatomic projectiles, such as SF 5 + , [1,2,3,4] C 60 + , [5,6,7] Au n + [8,9] and Bi n + , [10,11,12,13,14] greatly enhance the secondary ion yields of large fragments, thus leading to a clearer material identification. Especially, the bismuth liquid metal ion gun [15] (LMIG) is of great interest due to the capability of emitting doubly charged ion species, e.g.…”

Investigation of ionic liquids under Bi‐ion and Bi‐cluster ions bombardment by ToF‐SIMS

“…The primary ion current was directly measured using a Faraday cup detector located on a grounded sample holder (for Bi 1 + , Bi 2 + , Bi 3 + and Bi 3 2+ ) or was determined indirectly via extrapolation of target current measurements with adequate variation of pulse width at a given cycle time, usually 20 µs (for Bi 4 + , Bi 5 + , Bi 6 + , Bi 7 + and Bi 5 2+ ). [20,21] The difference between the measured ion currents was at maximum ±5% which is in good agreement to previously published data. [20,22,23] and a primary ion energy of 25 keV for single charged ion clusters and 50 keV for double charged ion clusters.…”

“…[20,21] The difference between the measured ion currents was at maximum ±5% which is in good agreement to previously published data. [20,22,23] and a primary ion energy of 25 keV for single charged ion clusters and 50 keV for double charged ion clusters. For each measurement the primary ion dose density was set to 1 × 10 10 ions cm −2 ensuring static conditions.…”

Investigation of block depth distribution in PS-b-PMMA block copolymer using ultra-low-energy cesium sputtering in ToF-SIMS

“…Therefore, we first investigated the ions that revealed the presence of polystyrene and PMMA in a homopolymer film for each of the polymers monitored using negative secondary ions. Analysis of samples was performed with the bismuth liquid metal ion gun, using Bi 3 + primary ion to reduce the fragmentation of polymers under ion bombardment . Negative ion spectrum of the homo‐PS sample was obtained after the depth profile, shown in Fig.…”