US 12,170,215 B2
Systems and methods for correction of impact of wafer tilt on misregistration measurements
Vladimir Levinski, Migdal HaEmek (IL); Daria Negri, Nesher (IL); and Amnon Manassen, Haifa (IL)
Assigned to KLA Corporation, Milpitas, CA (US)
Appl. No. 16/762,107
Filed by KLA Corporation, Milpitas, CA (US)
PCT Filed Apr. 5, 2020, PCT No. PCT/US2020/026794
§ 371(c)(1), (2) Date May 6, 2020,
PCT Pub. No. WO2021/206670, PCT Pub. Date Oct. 14, 2021.
Prior Publication US 2023/0197483 A1, Jun. 22, 2023
Int. Cl. H01L 21/67 (2006.01); H01L 21/66 (2006.01)
CPC H01L 21/67259 (2013.01) [H01L 22/12 (2013.01); H01L 22/26 (2013.01)] 12 Claims
OG exemplary drawing
 
1. A method for correcting misregistration measurements of a semiconductor wafer for errors therein arising from tilt of said wafer comprising:
measuring, for at least one location on a wafer, a difference between a Tool Induced Shift (TIS) of a metrology device in a first illumination arrangement with respect to said wafer wherein a surface of said wafer is generally orthogonally illuminated by an illumination source of said metrology device and a TIS of said metrology device in a second illumination arrangement with respect to said wafer, wherein said surface is obliquely illuminated by said illumination source; and
correcting a misregistration measurement measured by said metrology device at said at least one location for errors therein arising from tilt of said wafer at said location by subtracting from said misregistration measurement a weighted value of said difference between said TIS in said first and second illumination arrangements, wherein said difference between said TIS in said first and second illumination arrangements comprises a signature profile varying as a function of a parameter of said metrology device, wherein said metrology device illuminates said wafer by a multiplicity of wavelengths and said difference in TIS of said metrology device is measured as a function of said multiplicity of wavelengths, wherein said measuring said difference in TIS is performed at a plurality of locations Ns on said wafer and said difference in TIS of said metrology device is measured as a function of said multiplicity of wavelengths for each of said plurality of locations, and wherein said weighted value of said difference between said TIS in said first and second illumination arrangements is calculated by multiplying said difference between said TIS in said first and second illumination arrangements by a weighting coefficient.