Patent ID: 7969567

Claim:
A method for detecting the shape of a surface of a substrate having a pattern, comprising the steps of: illuminating a portion of the surface of the substrate rotating and moving in a single axial direction with light having a plurality of wavelengths, detecting an intensity of light reflected on the surface of the substrate for each wavelength, and detecting whether or not a data island arranged in the pattern is present on the illuminated portion of the surface of the substrate or whether or not the shape of the data island is good based on data on the detected intensities; illuminating the portion of the surface of the substrate with laser light, detecting light scattered at a first elevation angle with respect to the surface of the substrate and from the portion of the surface of the substrate illuminated with the laser light, and light scattered at a second elevation angle with respect to the surface of the substrate and from the portion of the surface of the substrate illuminated with the laser light, to obtain a first scattered light detection signal based on the light scattered at the first elevation angle, and to obtain a second scattered light detection signal based on the light scattered at the second elevation angle, processing the first and second scattered light detection signals, and detecting a defect causing the light to be scattered and present on the portion of the surface of the substrate; processing coordinates of the defect and information indicating the defect based on the result obtained in the step of detecting whether or not the data island is present on the illuminated portion of the surface of the substrate or whether or not the shape of the data island is good; processing coordinates of the defect and information indicating the defect based on the result obtained in the step of detecting the defect causing the light to be scattered; comparing the sets of the coordinates with each other to confirm whether or not the sets of the coordinates match each other; and removing information that indicates a defect whose coordinates match coordinates obtained in the step of detecting the defect causing the light to be scattered, wherein the processing result of the information obtained in the step of detecting whether or not the data island is present on the illuminated portion of the surface of the substrate or whether or not the shape of the data island is good is combined with the processed result of the information obtained in the step of detecting the defect causing the light to be scattered to detect the defect as an actual defect present on the surface of the substrate.