Programmed line width roughness metrology by multitechniques approach

Abstract

At modern manufacturing geometries, roughness control presents a huge challenge for the lithography step. For advanced nodes, this morphological aspect reaches the same order of magnitude as the critical dimension (CD). Hence, the control of roughness needs an adapted metrology. Specific samples with designed roughness have been manufactured using e-beam lithography. These samples have been characterized with three different methodologies: CD-scanning electron microscopy, optical critical dimension, and small angle x-ray scattering. The main goal is to compare the capability of each of these techniques in terms of reliability, type of information obtained, time to obtain the measurements, and level of maturity for the industry. The next step will be to develop a hybrid metrology approach for roughness determination with these techniques.