Critical Dimension Atomic Force Microscopy (CDAFM) is a nondestructive, high-resolution technique that enables accurate measurement of three-dimensional (3D) features. CD-AFM is accurate as it provides highly linear measurement over a range of line-widths and is unaffected by feature type, density or material type. Additionally, the technique is able to measure undercut features and can be calibrated using NIST traceable calibration standards to ensure accuracy of measurements. CDAFM capabilities have enabled its use as a reference metrology tool.