Patent ID: 6388756
Filing Date: 2002-05-14
Classification: G01B,G01N

Abstract:
An optical method for measuring a silicon trench depth, applicable to a substrate having a trench therein, wherein the substrate has a first surface, and the trench has a bottom surface to serve as a second surface as well as a depth, the method comprising steps of:measuring a total reflectance (R) from the substrate using different wavelengths, wherein R is determined by a first actual reflectance from the first surface, a second actual reflectance from the second surface, and a scattering factor; measuring the first actual reflectance from the first surface using different wavelengths; calculating the scattering factor; calculating the second actual reflectance from results of the first actual reflectance and the scattering factor; and determining the depth from the calculation result of the second actual reflectance.