npSCOPE: A New Instrument Combining SIMS Imaging, SE Imaging and Transmission Ion Microscopy for High Resolution In-situ Correlative Investigations

Abstract

In various research areas ranging from materials science to life sciences it becomes more and more important to be able to analyze the structure as well as the chemical composition at the nano-scale. For example, the size of electronic components becomes smaller and smaller increasing the need of having techniques to precisely follow dopant distributions with high spatial resolution. In the field of renewable energy devices, e.g. solar cells and batteries, the performance typically depends on the chosen material composition and distribution. Linking the underlying structure and composition at the nano-scale to the device's performance is therefore of utmost importance [1,2]. Similar needs for having high spatial resolution and high-sensitivity chemical information can be found in life sciences [3]. In nano-toxicology for instance, it is important to be able to reveal sub-cellular structures and simultaneously determine their chemical, elemental or isotopic composition in order to better understand relevant processes [4]. In most of the afore mentioned studies a number of different instruments is nowadays used to perform these investigations using correlative approaches. Being able to do such correlative studies in one single instrument is definitely beneficial for reducing the analysis time, speeding up the throughput as well as for facilitating the precise localization of the region of interests on the investigated samples. Therefore, we developed a multimodal nano-analytical platform allowing in-situ analysis of a same sample using different information channels. The instrument is equipped with the ultra-high resolution Gas Field Ion Source (GFIS) technology [5] allowing the sample to be irradiated with very finely focused He + and Ne + primary ion beams. This allows sub-nanometer spatial resolution when working with the secondary electron (SE) detection mode as imaging mode. Furthermore, the instrument incorporates a compact secondary ion mass spectrometer (SIMS) for chemical analysis of samples with excellent sensitivity and high dynamic range. The mass spectrometer is based on a double focusing magnetic sector design and allows sub-20 nm chemical imaging resolution [6-8]. Moreover, the SIMS system incorporates a new kind of detector for parallel mass detection providing a full mass spectrum for each analyzed pixel. The third newly developed detection mode available within the instrument is a position sensitive transmission detector located at the b…