Nanoscale Measurements with a Through-Focus Scanning-Optical-Microscope | NIST

Introduction In the current world of nanotechnology, fast and reliable measurement of nanoscale features is extremely useful. It is further advantageous if the analytical tools used are cost-effective and have high throughput, such as optics-based tools. In conventional optical microscopy, it is usually deemed necessary to acquire images at the “best-focus” position for meaningful analysis. However, the out-of-focus images do contain useful information regarding the target. On the basis of this, we introduce a new method for nanoscale dimensional analysis with nanometer sensitivity using a conventional optical microscope. The method is called the through-focus scanning optical microscope (TSOMpronounced “tee-som”) imaging method.[1-5] The TSOM method is applicable to 3D targets, enabling the method to be used for a wide range of target geometries.