| 摘要 |
PURPOSE:To accurately measure a dimension even with respect to an object having a complicated shape, by determining the optimum focus position on the basis of a stable reference pattern other than an object to be measured prior to performing measurement. CONSTITUTION:An optical system 7 such as a lens system projecting the edge image of a resist pattern 6a to be measured and that of a reference resist pattern 6b having a width sufficient to measure is arranged above a semiconductive substrate 1 and these images are processed by a signal processing system 8 to perform the display of a dimension or the determination of the optimum focus. The signal from the processing system 8 is transmitted to a focus driving mechanism 11 and a stage 12 is moved up and down to regulate the position of a focus. In order to determine the position of the optimum focus, the resist pattern 6a to be measured is not used but the reference resist pattern 6b is used. Since the reference resist pattern 6b has a large size, there is no interference of both edges and, therefore, the focus is accurately matched. |
