Precise lateral measurements of step height standards using Hamming area model

Abstract

Since the ISO 5436 profile analysis presents the axial measurements of the step height/depth standards and does not present a direct method for the lateral measurements, a new method based on the Hamming area model for the lateral measurements of step height/depth standards is presented. The basic idea of the method is to mimic the experimental profile of the step height/depth by a combination of the Hamming window pass-band filter and the RMS model. The lateral position of the 50 % height/depth value of the mimicked Hamming height/depth is assigned. The areas up and down the assigned value are then computed and compared for the lateral measurements of the step height/depth standard. The method is applied for the lateral measurements of a groove structure of a transparent step depth standard. The results show that the total area included in the right line edge of the groove structure is greater than the total area included in the left line edge by 151.66 nm. The error in area measurement is computed to be 1.7 %. The proposed method can be applied to any step height/depth regardless of its height/depth, width, and sharpness of the line edges.