Real-time traceability method of width of defect based on divide-and-conquer

A real-time traceability method of a width of a defect based on divide-and-conquer, the real-time traceability method comprising steps of:

• (1) estimating the width of the defect through a calibration transfer function (CTF) based on standard defect digital calibration technology, recording the width of the defect estimated through the CTF as WCTF, wherein if WCTF is greater than 5 μm, which means that the width of the defect complies with geometric imaging law and is located in a linear segment of the CTF, then WCTF acts as an accurately estimated value of an actual width of the defect;
• if WCTF is less than or equal to 5 μm, which means that the width of the defect is smaller, diffraction broadening occurs during imaging, the width of the defect no longer complies with the geometric imaging law, and WCTF acting as the estimated value of the actual width of the defect has a large error, then at this time, a step of (2) is executed;
• (2) estimating the width of the defect through a multidimensional eigenvector analysis technology based on an electromagnetic field simulation database of defect scattered dark-field imaging;
• recording the width of the defect estimated through the multidimensional eigenvector analysis technology as a regression width Wregrs, wherein if Wregrs is greater than a diffraction limit σ0 of a dark-field imaging system, then the regression width Wregrs acts as the accurately estimated value of the actual width of the detect;
• if Wregrs is less than or equal to the diffraction limit σ0, the regression width Wregrs is unable to distinguish different widths in a width range which is less than or equal to the diffraction limit σ0, then at this time, a step of (3) is executed;
• and
• (3) processing a dark-field image and extracting the width of the defect through an adaptive threshold segmentation method, recording the width of the defect extracted through the adaptive threshold segmentation method as an imaging width Wimg, wherein if the imaging width Wimg is greater than the diffraction limit σ0, the imaging width Wimg is unable to distinguish different widths, then the regression width Wregrs still acts as the estimated value of the actual width of the defect;
• if the imaging width Wimg is less than or equal to the diffraction limit σ0, then the imaging width Wimg acts as the estimated value of the actual width of the defect.