ABSTRACT
Light microscopy is of great importance for basic research, analysis in materials science and for the practical control of fabrication steps. When used conventionally it serves to reveal structures of objects which are otherwise invisible to the eye or magnifying glass, such as micrometre-sized structures of microelectronic devices on silicon wafers. The lateral resolution of the technique is determined by the wavelength of the light and the objective of the microscope. However, the quality of the microscopic image is not solely determined by resolution; noise and lack of contrast may also prevent images of high quality being obtained and the theoretical resolution being reached even if the optical components are ideal. The working range of the light microscope in comparison to other microscopic techniques is depicted schematically in table B1.18.1. Clearly, the light microscope has an operating range from about half a micrometer up to millimetres, although recent developments in improving resolution allow the lower limit to be pushed below half a micrometer.
