Critical Dimension Measurement in Nanometer Scale by Using Scanning Probe Microscopy

This paper describes and demonstrates a new method using scanning probe microscopy for nanometer-order measurements of critical dimensions. The modeling equation, which includes the critical dimensions of both the sample and the probe, is derived from a mathematical relationship between the sample, probe, and image. The dimensions, which are the fitting parameters of the modeling equation, can be calculated from the height dependence of apparent width in SPM images. The feasibility of this method was confirmed by measuring several structures fabricated by nanofabrication.