SIMS Analysis of Thin EUV Photoresist Films

Abstract

This study reports on the application of secondary ion mass spectrometry (SIMS) for examining thin (20−50 nm) chemically amplified resist films on silicon. SIMS depth profiling was carried out using a gas cluster ion beam to ensure minimal sputter-induced damage to the organic constituents of interest. Specific attention concerned the distribution of the photo acid generator (PAG) molecule within these films, along with the photo-induced fragmentation occurring on extreme ultra-violet photo exposure. Positive secondary ion spectra were collected using a traditional time of flight (ToF)-SIMS and the latest generation IONTOF Hybrid SIMS instrumentation equipped with an Orbitrap TM mass analyzer. Tandem mass spectrometry (MS/ MS) capability within the Orbitrap TM secondary ion column was utilized to verify that the C 19 H 17 S + secondary ion did indeed have the molecular structure consistent with the PAG structure. The superior mass resolving power of the Orbitrap TM mass analyzer (∼20× of the ToF mass analyzer) along with improved mass accuracy (a few ppm) proved pivotal in the mass spectral and depth profile analysis of these films. This was not the case for the ToF-SIMS experiments, as the mass spectra, as well as the associated depth profiles, exhibited severe molecular (isobaric) interferences.

Chemically Amplified Molecular Glass Photoresist Regulated by 2-Aminoanthracene Additive for Electron Beam Lithography and Extreme Ultraviolet Lithography

“…Secondary ion mass spectrometry (SIMS) is a successful technique for analyzing sample surface and has made much progress in photoresist research. − Bi 3+ ion was used as a primary ion source to bombard the sample surface, and obtained the distribution information on PAGs, BPA-6-epoxy and 2-aminoanthracene in the vertical direction (Figure C). CN – ion is the characteristic ion of the 2-aminoanthracene and the content change reflects the vertical distribution of 2-aminoanthracene in the film.…”

Direct Electrochemical Functionalization of Graphene Grown on Cu Including the Reaction Rate Dependence on the Cu Facet Type

“…We acquired SIMS spectra on the samples by sputtering using 5 keV Ar cluster ions over a region of 250 × 250 μm 2 and cropping 150 × 150 μm 2 for the depth profiling. Ar cluster ion beams can allow for detecting organic molecules without fragmenting them. , The aniline molecules are identified by the C 6 H 7 N + peak ( m / z 93.0576). The pristine graphene and the graphene reacted in TBAPF 6 solution without 4-iodoaniline did not show any C 6 H 7 N + signal, while the functionalized graphene samples exhibited C 6 H 7 N + peaks with intensity increasing as a function of the reaction time.…”

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

“…In the first example, Spampinato et al used two SIMS instruments to analyse the photoresists. 208 One instrument was a conventional TOF-SIMS instrument whereas the other was equipped with an Orbitrap mass analyser with MS/MS capability meaning that greater mass resolution could be achieved. The operating conditions for both instruments were kept as close as possible so that data could be compared.…”

“…This next section describes those papers that have contributed to improving depth-profiling studies. 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.…”