In-line metrology of high aspect ratio structu with MBIR technique

This paper presents recent results obtained applying the Model Based Infrared Reflectometry (MBIR) technique as an in-line monitoring technique for high aspect ratio structures. The paper will focus on the description of the metrology development and its implementation in a manufacturing environment for the particular case of few microns Deep Trench Isolation (DTI) structures. The technique is demonstrated to be robust method for the in-line geometry control of etched structures. Experimental data relating to high aspect ratio Through Silicon Via (TSV) structures will be presented as well. The results confirm that the technique is very sensitive to the geometry even for small Via of diameter down to 3 microns.