US 12,111,270 B2
Method of inspecting a wafer and apparatus for performing the same
Juntaek Oh, Hwaseong-si (KR); Jinwoo Ahn, Yongin-si (KR); Kijoo Hong, Seoul (KR); Youngkyu Park, Incheon (KR); and Eunsoo Hwang, Seoul (KR)
Assigned to SAMSUNG ELECTRONICS CO., LTD., Suwon-si (KR)
Filed by Samsung Electronics Co., Ltd., Suwon-si (KR)
Filed on Apr. 21, 2022, as Appl. No. 17/725,917.
Claims priority of application No. 10-2021-0131368 (KR), filed on Oct. 5, 2021.
Prior Publication US 2023/0104399 A1, Apr. 6, 2023
Int. Cl. G01N 21/95 (2006.01); G01N 21/21 (2006.01); G01N 21/55 (2014.01)
CPC G01N 21/9501 (2013.01) [G01N 21/21 (2013.01); G01N 21/55 (2013.01); G01N 2201/121 (2013.01)] 17 Claims
OG exemplary drawing
 
1. A method of inspecting a wafer, the method comprising:
generating a reference incident light including a plurality of wavelengths;
measuring, by wavelength, an intensity of the reference incident light by the wavelengths and storing the measurement as stored reference incident light intensity;
irradiating the reference incident light to the wafer;
measuring, by wavelength, an intensity of a reference reflected light by the wavelengths and storing the measurement as stored reference reflected light intensity, the reference reflected light generated as a result of irradiating the reference incident light to the wafer;
generating an incident light including the plurality of wavelengths;
measuring, by wavelength, an intensity of the incident light and storing the measurement as stored incident light intensity;
irradiating the incident light to the wafer;
measuring, by wavelength, an intensity of a reflected light from the wafer and storing the measurement as stored reflected light intensity, the reflected light generated as a result of irradiating the incident light to the wafer;
determining a difference, at individual wavelengths, between the stored reflected light intensity and the stored reference reflected light intensity; and
correcting, by wavelength, the stored reflected light intensity based on the determined difference,
wherein there is a time lapse between when the stored reference reflected light intensity is measured and when the stored reflected light intensity is measured.