Optical Measurement of Edge Angles
Original Publication Date: 1985-Oct-01
Included in the Prior Art Database: 2005-Feb-19
An arrangement for optical measurement of edge profiles of electronic devices is proposed that permits accurate, non-destructive and fast edge-angle determination. It comprises a reflecting microscope with a photomultiplier for receiving and amplifying the light reflected from the edge under investigation. A rotatable sample holder is equipped with an angle decoder, and the reflected light amplitude is recorded as a function of the rotation angle on an x-y plotter. Measurements are possible even for edge widths smaller than the wavelength of the sampling light used. The concept of the measuring system is schematically shown in the figure. The sample with the edge to be investigated is affixed to a sample holder that allows rotation around the edge to be measured, in the figure denoted as edge rotation axis.