Optical Profilometry

Optical profilometry is a rapid, nondestructive, and noncontact surface metrology technique. An optical profiler is a type of microscope in which light from a lamp is split into two paths by a beam splitter. One path directs the light onto the surface under test, the other path directs the light to a reference mirror. Reflections from the two surface are recombined and projected onto an array detector. When the path difference between the recombined beams is on the order of a few wavelengths of light or less interference can occur. This interference contains information about the surface contours of the test surface. Vertical resolution can be on the order of several angstroms while lateral resolution depends upon the objective and is typically in the range of 0.3-8 microns.

Technique Advantages
  • True imaging (area measurement, not serially point by point)
  • Fast data acquisition over large areas
  • Noncontact and nondestructive
  • Large Z-axis range, from a few nanometers up to feature heights as great as 2 cm
  • Variable field of view, from 6mm down to 8µm
  • Critical dimension measurements (X,Y, and Z)
Typical Applications
  • surface topography
  • coating thickness
  • step height
  • 3D imaging
Instrumentation
Zygo NexView 3D
  • 2.5x, 10x, 20x, 50x, and 100x objectives
  • automated image stitching
Training and Operating Procedure

Visit e-education.psu.edu/mcl-optpro