Inspection device and inspection method
The purpose of the present disclosure is to provide a technology which enables, in a step for analyzing a defect of an element, identification of the position of the defect even in a case where the defect is thin or there is an influence of contamination. An inspection apparatus according to the present disclosure irradiates a first region including a defect of a sample with a low-energy first electron beam and then generates a second electron beam image obtained by irradiating a second region including the first region with a high-energy second electron beam, and identifies the position of the first region in the second electron beam image, thereby identifying the position of the defect.
1 . An inspection apparatus that inspects a defect of a sample using an image obtained by irradiating the sample with an electron beam, the apparatus comprising:
a computer system that generates the image using a result of detecting secondary particles generated from the sample by irradiating the sample with the electron beam, wherein
the computer system irradiates a first region including the defect on the sample with a first electron beam having first landing energy and then generates a second electron beam image obtained by irradiating a second region of the sample including the first region with a second electron beam having second landing energy higher than the first landing energy,
the computer system specifies a position of the first region in the second electron beam image by using information representing the position of the first region, and
the computer system determines an irradiation position of a third electron beam for performing an element analysis on the defect in the first region based on the specified position of the first region.
2 . The inspection apparatus according to claim 1 , wherein
the computer system generates a first electron beam image obtained by irradiating the first region with the first electron beam,
the computer system specifies a position of the defect in the first electron beam image, and
the computer system determines the irradiation position of the third electron beam using the position of the defect in the first electron beam image and the position of the first region within the second electron beam image.
3 . The inspection apparatus according to claim 2 , wherein
the computer system generates, as the first electron beam image, an image that includes contamination that occurs in the first region by irradiating the first region with the first electron beam, and
the computer system specifies the position of the first region within the second electron beam image by specifying a position of the contamination within the second electron beam image.
4 . The inspection apparatus according to claim 3 , wherein
the computer system includes a storage unit that stores a template image representing a shape of the contamination,
the computer system acquires the information representing the position of the first region by searching for a location that matches the template image in the second electron beam image, and
the computer system specifies the position of the first region within the second electron beam image according to the information obtained by searching using the template image.
5 . The inspection apparatus according to claim 4 , wherein
the storage unit stores, as the template image, two types of images of
a first template having a rectangular region that has a first brightness value and a peripheral region that surrounds the rectangular region and has a second brightness value, and
a second template in which a gradation of the first template is inverted, and
the computer system searches for a location that matches at least one of the first template and the second template in the second electron beam image.
6 . The inspection apparatus according to claim 4 , wherein
the computer system specifies an outer periphery of the second region by identifying a frame shape formed on the outer periphery of the second region in the first electron beam image, and
the computer system performs a search using the template image only inside the specified second region.
7 . The inspection apparatus according to claim 1 , wherein
the computer system generates, as the second electron beam image, an image including a marking formed on the sample by irradiating the sample with a fourth electron beam having a higher irradiation density than the first electron beam,
the computer system acquires the information representing the position of the first region by searching for the marking in the second electron beam image, and
the computer system specifies the position of the first region within the second electron beam image according to the information obtained by searching using the marking.
8 . The inspection apparatus according to claim 7 , wherein
the computer system generates, as a first electron beam image obtained by irradiating the first region with the first electron beam, an image obtained when contamination generated in the first region by irradiating the first region with the first electron beam is less than a threshold value, and
the computer system specifies the position of the first region within the second electron beam image without depending on the position of the contamination by searching for the marking in the second electron beam image.
9 . The inspection apparatus according to claim 7 , wherein
the marking is square and formed outside the first region.
10 . The inspection apparatus according to claim 1 , wherein
the computer system includes a user interface that presents at least one of
the specified position of the first region,
the position of the first region within the second electron beam image,
the position of the defect in the second electron beam image,
a result of performing the element analysis on the position of the defect, and
the second electron beam image.
11 . The inspection apparatus according to claim 1 , wherein
the sample is a wafer or bare wafer on which no pattern is formed.
12 . An inspection method for inspecting a defect of a sample using an image obtained by irradiating the sample with an electron beam, the method comprising:
a step of generating the image using a result of detecting secondary particles generated from the sample by irradiating the sample with the electron beam, wherein
the step of generating the image includes a step of irradiating a first region including the defect on the sample with a first electron beam having first landing energy and then generating a second electron beam image obtained by irradiating a second region of the sample including the first region with a second electron beam having second landing energy higher than the first landing energy,
the step of generating the image includes a step of specifying a position of the first region in the second electron beam image by using information representing the position of the first region, and
the step of generating the image includes a step of determining an irradiation position of a third electron beam for performing an element analysis on the defect in the first region based on the specified position of the first region.