A Novel Method for Determining AFM Probe Tip Characteristics Using Trench-Based Reference Material

Abstract In the measurement of nanomaterials via atomic force microscopy (AFM), the measured size is different from the real value by a large offset value because of the radius and cone angle of the tips used. To ensure the reliability of AFM images by correcting the offset value, we need to precisely determine the radius and cone angle of AFM tips. Herein, a certified reference material (CRM) with a series of trenches having different trench widths ranging from 10 to 200 nm is developed to determine the radius and cone angle of AFM tips. The trench widths of the CRM are traceably certified via high-resolution transmission electron microscopy in reference to the lattice constant of the Si(110) plane within the Si(100) substrate. The radius of the tip can be determined in narrow trenches when the penetration depth of the tip is shallower than half the trench width. However, the cone angle of the tip can be determined in wide trenches in which the tip can touch the bottom of the trench. Consequently, the radius and cone angle of AFM tips can be determined using certified trench widths of the CRM.