Nano-scale molecular analysis of photo-resist films with massive cluster secondary ion mass spectrometry

Here we describe a methodology for molecular analysis at the nano-scale and present its capabilities. The analysis method is based on secondary ion mass spectrometry, SIMS, with gold nanoparticles (e.g. Au4004+). The methodology presented here has unique features which enable molecular analysis at the nanoscale, namely the method of acquiring the mass spectrum and the nature of the impacting projectile. In the method a sequence of individual gold nanoparticles (Au4004+) are used to bombard the sample, each impact results in ion emission from an area 10-20 nm in diameter. For each of impact of Au4004+, the emitted ions are mass analyzed by time of flight mass spectrometry, detected and stored together in one mass spectrum prior to the arrival of the subsequent projectile. Each mass spectrum contains elementals, and molecules which were co-localized within 10-20 nm of one another. Examining the co-emitted ions allows to test the molecular homogeneity, and chemical composition at the nanoscale. We applied this method to a chemically amplified resist before and after exposure and development. After development the method was used to chemically characterize defect sites, which were not removed by the developing solution.