Patent ID: 6646751
Filing Date: 2003-11-11
Classification: G01B,H01L

Abstract:
A method for measuring a depth of a subject trench comprising the steps of forming, on a substrate, a plurality of measurement trenches having different widths ai (aii+1, i=1, 2,. . . , n) and a depth equal to the depth d0 of the subject trench, irradiating the measurement trenches with a parallel ray at an incidence angle of &thgr; with respect to the surface of the substrate while detecting the reflect ray from the substrate, separating the measurement trenches into a first group providing dark images and a second group providing bright images, and calculating a range for the depth d0 by using a largest width ak of the measurement trenches in the first group and a smallest width ak+1 of the measurement trenches in the second group based on the following relationship:(ak/2)tan &thgr;<d0&lE;(ak+1/2)tan &thgr;.