Method for Measurement of Edge Slopes of Relief Structures Having Heights the Order of One Micron or Less
Original Publication Date: 1981-Oct-01
Included in the Prior Art Database: 2005-Feb-12
A method for the measurement of conductor edge slopes having heights of the order of 1 micron or less is based on the observation of the diffraction pattern 10 of light 12 reflected from the sloped conductor edge 14, as shown in Fig. 1. Illumination 16 is at near normal incidence to the conductor edge 14. The light which directly strikes this edge is directly "retroreflected" and diffraction spread. The central direction (2 theta(E)) and the substrate inclination allow the edge 14 slope to be computed as phi = theta(N) - theta(E).