Advances of Confocal Microscopy in Three-Dimensional Surface Topography Measurement

With the rapid development of precision instrument manufacturing and semiconductor processing industry, the observation and measurement of micro-structure surface profile has become an important orientation of scientific research. Laser scanning confocal microscopy becomes popular in three-dimensional (3D) surface topography because of its high resolution, high signal- to-noise ratio, and excellent optical sectioning ability. In this paper, we first introduce the basic principle of the confocal microscopy. Further, various confocal microscopic methods used in 3D surface topography measurement are reviewed, including different scanning methods, different detection methods, and different spectral- based confocal imaging methods. Finally, the future developments of confocal microscopy are also prospected.