Method of discriminating between an object region and a ground region and method of measuring three dimensional shape by using the same

A method of discriminating between an object region and a ground region, the method comprising:

• irradiating grating patterned light onto a measurement target, changing grating pattern, to obtain grating patterned image by receiving the grating patterned light reflected by the measurement target;
• obtaining a resultant image of at least one of average, maximum value, minimum value, modulation, visibility, phase and signal to noise ratio in each position of the grating patterned image;
• and
• discriminating the object region and the ground region by using the resultant image.

A method of discriminating between an object region and a ground region, the method comprising:

• determining a type of a light source between a light source generating a light and a light source generating a grating patterned light, in accordance with a surface roughness of a measurement target;
• discriminating between the object region and the ground region by a first step, when the surface roughness of the measurement target is lower than a predetermined value, the first step comprising:
• irradiating the light through the light source generating a light;
• receiving the light reflected by the measurement target to capture an image;
• and
• discriminating between the object region and the ground region by using the image;
• and
• discriminating between the object region and the ground region by a second step, when the surface roughness of the measurement target is higher than the predetermined value, the second step comprising:
• irradiating the grating patterned light through the light source generating the grating patterned light onto the measurement target in at least one direction, shifting a grating pattern, to obtain a grating patterned image by receiving the grating patterned light reflected by the measurement target;
• and
• discriminating the object region and the ground region by using the patterned image.

A method of measuring three dimensional shape, the method comprising:

• irradiating a plurality of patterned lights onto a substrate to capture patterned images by receiving the patterned light reflected by the substrate;
• merging the patterned images to generate an image;
• obtaining intensity of each position in the inspection region from the image;
• generating a grayscale histogram by setting the intensity to be a first axis and the number of positions corresponding to the intensity to be a second axis;
• obtaining height of each position in the inspection region by using the patterned images;
• discriminating an object region and a ground region by using the histogram;
• and
• setting up a height of the ground region as a ground height with respect to a measurement target.