Zastosowanie skaningowej interferometrii w świetle białym do oceny topografii powierzchni

W pracy sprawdzono możliwości zastosowania skaningowej interferometrii w świetle białym do oceny topografii powierzchni wykonanych z różnych materiałów. W artykule opisano podstawy tej metody oraz wskazano na jej zalety i pewne ograniczenia. W badaniach zastosowano skaningowy interferometr Talysurf CCI 6000 firmy Taylor Hobson, wykorzystujący koherencyjną interferometrię korelacyjną. W rezultacie przeprowadzonych badań określono możliwości zastosowania tej techniki pomiarowej do oceny topografii powierzchni wykonanych z różnych materiałów oraz podstawowe parametry metrologiczne zastosowanej metody.

White light scanning interferometry also referred to as white light vertical scanning interferometry or coherence correlation interferometry is a well-known method for measuring the surface topography with high accuracy. It is a non-contact optical method for surface height measurement on 3-D structures with the surface heights varying between tens of nanometers to a few millimeters. This method is based on analysis of the maximum value of the temporal degree of coherence of two interfering waves. The analysis takes place at all points of the measured surface simultaneously. The paper describes the principles of white light vertical scanning interferometry application to the surface topography assessment. This method has a number of advantages. Large unambiguous measurement range, high accuracy and short measurement times are among the key features. However, surfaces with relatively large local surface slopes or height steps often give rise to significant measuring errors. The errors result from non-geometrical phenomena such as diffraction and other reflecting effects, which cause changes of the height values obtained from the envelope maximum of the white-light interference signal. The results of topography evaluation of various surfaces accomplished with this method are presented in the paper. The interference microscope Talysurf CCI 6000 with TalyMap Platinum software by Taylor Hobson was used to take the measurements.