Image enhancement for multi-layered structure in charged-particle beam inspection

An image enhancing apparatus comprising:

• a memory storing a set of instructions;
• and
• at least one processor configured to execute the set of instructions to cause the apparatus to perform:
• acquiring a first image and a second image of multiple stacked layers of a sample that are taken with a first focal point and a second focal point, respectively;
• associating a first segment of the first image with a first layer among the multiple stacked layers and associating a second segment of the second image with a second layer among the multiple stacked layers;
• estimating a first blurriness degree of the first segment based on a first reference image corresponding to the first layer and estimating a second blurriness degree of the second segment based on a second reference image;
• updating the first segment according to the first blurriness degree and updating the second segment according to the second blurriness degree;
• and
• combining the updated first segment and the updated second segment to generate a combined image including the first layer and the second layer.

A non-transitory computer readable medium that stores a set of instructions that is executable by at least one processor of a computing device to perform a method for enhancing an image, the method comprising:

• acquiring a first image and a second image of multiple stacked layers of a sample that are taken with a first focal point and a second focal point, respectively;
• associating a first segment of the first image with a first layer among the multiple stacked layers and associating a second segment of the second image with a second layer among the multiple stacked layers;
• estimating a first blurriness degree of the first segment based on a first reference image corresponding to the first layer and estimating a second blurriness degree of the second segment based on a second reference image;
• updating the first segment according to the first blurriness degree and updating the second segment according to the second blurriness degree;
• and
• combining the updated first segment and the updated second segment to generate a combined image including the first layer and the second layer.