Method of removing defect of mask

A method of removing a defect of a mask, the method comprising:

• scanning an offset calibration region included in a mask using a probe of an atomic force microscope (AFM) to obtain an AFM image of the offset calibration region and calibrating an offset of the probe of the AFM by adjusting a zero point;
• generating a probe profile by comparing the AFM image of the offset calibration region with a design image of the offset calibration region, the probe profile including characteristics of the probe of the AFM;
• generating a design-based reference image of a defect area by applying the probe profile to a design image of the defect area of the mask including a location of the defect;
• obtaining an AFM image of the defect area by scanning the defect area of the mask using the probe of the AFM;
• recognizing the defect as a recognized defect by comparing the AFM image of the defect area with the design-based reference image;
• and
• removing the recognized defect using the probe of the AFM.

A method of removing a defect of a mask, the method comprising:

• preparing a mask including a substrate having a main exposure area and an offset calibration region, patterns on the substrate in the main exposure area, and a dummy pattern on the substrate in the offset calibration region;
• obtaining an atomic force microscope (AFM) image of the offset calibration region by scanning the offset calibration region of the mask using a probe of an AFM, and calibrating the offset of the probe of the AFM by adjusting a zero point;
• generating a probe profile by comparing the AFM image of the offset calibration region with a design image of the offset calibration region, the probe profile including characteristics of a probe of the AFM;
• generating a design-based reference image of a defect area by a convolution of a design image of the defect area of the mask including a location of the defect and the probe profile;
• obtaining an AFM image of the defect area by scanning the defect area of the mask using the probe of the AFM;
• recognizing the defect as a recognized defect by comparing the AFM image of the defect area with the design-based reference image;
• removing the recognized defect using the probe of the AFM;
• and
• performing a cleaning process on the mask.