Nanoscale electrical characterisation is key to understand the performance of semiconductor devices as well as potential failure modes. One widely used technique for this is Atomic Force Microscopy (AFM). Using a large number of complementary AFM techniques such as scanning microwave impedance microscopy (sMIM) Kelvin probe force microscopy (KPFM) and conductive AFM it is possible to characterise the majority of material properties in your semiconductor device system, from simple I-V curves to dopant concentrations maps (down to 1014 atoms/cm3). The ability of our Cypher and MFP-3D AFMs to combine a number of these techniques allows you to fully understand and optimise your device performance.
Often it is necessary to correlate these nanoscale electrical responses with electron microscope imaging, for example in device failure analysis where a defect must be localised for later isolation and further characterisation. This is made possible with our omniprobe nanomanipulator series where electrical properties imaging techniques such as electron beam induced current (EBIC) and electron beam absorbed current (EBAC) can be performed whilst making contact to 10 nm features.
Once a failure is identified and located in a device it is usually necessary to remove that structure for further analysis either in a different instrument (e.g. transmission electron microscope) or to achieve a more favourable set of conditions in the same instrument (e.g. Focused ion beam). The demands of the semiconductor industry require a repeatable process with a typical time of less than 30 minutes per sample. The difficulty of this task is further increased as devices head towards the 3 or 5 nm node as this requires specimen thicknesses to be less than 20 nm. OmniProbe 400 is the perfect tool to achieve all of this the piezo-driven motion allows repeatable positioning at the 10nm scale whilst the concentric rotation allows advanced preparation geometries to be achieved with ease, this leads to the highest possible quality specimens.
You can also combine the OmniProbe400 with AZtec LayerProbe to allow lift-out in tandem with local thickness measurement to enable true process control of thin specimen preparation.
For failure analysis in semiconductor devices metallised layers must be exposed. This becomes ever more challenging as node sizes in devices become smaller and architectures become ever more 3 dimensional. Our Plasma assisted etch tools ensure that multiple semiconductor compounds whether it be oxides, nitrides or polymides are removed accurately without lifting or damaging the metallisation. Our flexible FA tool allows die deprocessing up to 10x faster than the previous process to ensure maximum throughput and productivity.
Once a failed device has been found and isolated from the rest of the die, the true detective work begins to identify the root cause of that failure. The cause of that failure could be due to inconsistency in the chemistry of the process, foreign contaminant particles or variation in crystalline structure of deposited material amongst many other possibilities. Many of these potential fault causes are extremely small, typically on the order of a few nanometres. Our latest generation Ultim Extreme energy dispersive x-ray spectrometer (EDS) allows you to work at the same conditions that you would image in the SEM to get elemental information at 10 nm resolution on bulk devices.
Not all device failures are chemical in nature. Some are due to the structure or even phase of deposited material. Electron backscatter diffraction (EBSD) collects an electron diffraction pattern at every pixel of an SEM image allowing characterisation of local crystal structure. By processing these diffraction patterns the grain structure, relative orientations, grain boundary orientations and even local stress and strain can be analysed. This allows correlation of device properties with the structure which can be particularly useful for understanding the conductivity of metailsed interconnects and through silicon vias. Combined with EDS the phase of a material can be determined not just its structure or elemental composition. Symmetry EDSD is the first CMOS based detector delivering higher speed and sensitivity that any other EBSD camera. This enables the user to collect higher quality data in a shorter time maximising productivity.
For the data storage industry, understanding the nanometre scale magnetic behaviour of magnetic disk media is crucial to understanding its performance in the final device. Magnetic force microscopy (MFM) allows the direct imaging of magnetic domain structure of disk media and other magnetic devices. Whether in the analysis of magnetically recorded bits or in the performance of transducers that read/write them, our MFP-3D Infinity AFM with variable field module (VFM) allows accurate analysis of the most challenging specimens.
MFM can also be used alongside piezoelectric force microscopy (PFM) to characterize the magnetoelectric coupling of multiferroic composites. These materials are of significant research interest due to their usability in dual electric-field- and magnetic-field-tunable signal-processing devices.