Rasterelektronenmikroskop - PR1253394-2790-W

1 Piece Scanning electron microscopy (SEM) is a widely used analytical tool for materials analysis, combining non-destructive, user-friendly operation with extensive possibilities for materials characterisation. In addition to imaging of material surfaces, SEM enables a variety of spectroscopic and diffraction-based methods for analysing chemical composition, crystallographic properties and structural defects. With a field-emission SEM (FE-SEM), a broad magnification range can be accessed, extending to sub-nanometre resolution. As a leading institute in the field of (ultra-)wide bandgap materials, we require an SEM that supports a broad range of materials-science characterisation tasks. These includes, in particular, the characterisation of (ultra-)wide band gap bulk crystals, fine-grained source materials, raw substrates with respect to intrinsic defects and residual damages e.g. from polishing processes, substrates with epitaxial layers for (opto-) electronic devices and fully processed device wafers. The key requirements for the intended SEM can be grouped into three main aspects: 1) An electron optical system providing state-of-the-art high lateral resolution down to the sub-nanometre range. This must be combined with a comprehensive detector set, including chamber-detectors for secondary (SE) and backscattered (BSE) electrons, as well as In-lens detectors for both SE and BSE electrons, with selectable energy ranges and clear separation of the respective signals. A field-free objective lens is preferred, without restrictions caused by magnetic reaction particles or focus problems arising from conductive channels (e.g. electron devices) tilted into the strong lens field. Acceleration voltage and beam current must be changed easily and independently between high-resolution and analytical operating conditions without much realignment. A technical solution for bypassing sample charging is required, since some of our materials are electrically insulating due to their wide bandgap or are mounted on insulating substrates. 2) A key requirement is the ability to investigate wafers using multiple techniques, such as electron channelling contrast imaging (ECCI) and cathodoluminescence (CL) analysis on the same region of interest (ROI). For wafers up to 8 inches, it must be possible to access any position from the centre to the wafer edge without losing the ROI under preferred ECCI conditions, for example due to wafer rotation or repeatability-uncertainties during long-range x/y movements in automated data collection. For wafers up to 12 inches, the largest possible area should be accessible. For typically low dislocation densities (< 104 cm−2), high pixel numbers and a large field of view at low magnification, up to 400 × 400 µm, are essential for comparing ECCI and CL results. The use of internally and externally recorded images, including images acquired by other techniques, shall be possible for sample navigation, enabling reliable relocation of selected features across the full wafer within a few micrometres. This is particularly important, when features are only visible at high magnification in non-standard electron images, such as CL-contrast or little dislocations in diffraction mode. 3) Automated data acquisition must be available for a wide range of capabilities. The system shall provide a comprehensive software solution for automated control of electron microscope functions and for freely arranging these functions within selected ROIs across the wafer. This shall be implemented through a modern, intuitive graphical user interface with a drag-and-drop workflow builder, allowing users to combine virtually any microscope function with defined ROI lists in any desired sequence including loops, conditional if/else logic and modular grouping of workflow elements. Automated imaging workflow shall not be limited to large field-of-view acquisition but must also enable high-resolution image acquisition. In addition, the system shall include integrated scripting capabilities that allow the execution of customer-specific Python codes, the extraction, modification and re-inclusion of Python subcodes to build up customised and advanced automation and data-processing recipes. Options 1.1.21 Software for evaluation of ECP pattern A Software, which allows indexing of diffraction lines and identifying tilt angles based on measured electron channelling patterns. 1.2.9 Additional feedthroughs Cable and nitrogen feedthroughs for an EBIC stage and a nitrogen cooling stage. 1.2.10 Plasma cleaner A plasma cleaner inside the main chamber. 1.4.11 Software for layered sample analyses Software for analysing layered samples with thicknesses from the nanometre to micrometre range is requested, based either on specified layer thicknesses or on individual layer compositions.