扫描探针显微镜下微纳结构深度测量的校准方法

Scanning probe microscopy (SPM) is an essential technology for three-dimensional measurement of nano/microstructure. However, there are uncertain profiles near step or groove sample edges, which bring about accuracy loss of depth measurement. In order to avoid the accuracy loss of depth measurement, two analytical models for mechanical probes and optical probes were established respectively, the coupling relationships among uncertain profiles, depth of samples, and shape of probes were depicted. Based on the above models, a calibration method for depth measurement with a promising accuracy was proposed. Compared with the existing international standard for depth measurement (W/3 rule), the proposed method provides a clear boundary to determine if the measurement results are valid. Furthermore, it can also guide the user to select the appropriate probe before performing measurements.