A novel approach for the high speed 3D measurement using a linescan-based chromatic confocal microscopy

The linescan-based chromatic confocal microcopy proposed in this study is one of the three-demensional (3D) surface topography technologies to measure, for example, a nanoscale critical dimension (width and height) in the manufacturing process of semiconductors at high speed and high resolution. The chromatic confocal microscopy is slow in general since it makes use of a point beam scanning method. In this research, the speed of 3D reconstruction and measurement is dramatically improved by adapting a linescan method and designing an illumination and a spectrometer optimally. For the illumination source, a supercontinuum laser with a high power and a uniform spectrum is applied. Furthermore, a high speed spectrometer is designed using an optical grating and a high speed profile camera. Finally, VLSI and KRISS standard specimens are used for the comprehensive performance evaluation such as resolution, repeatability and so on.