公开(公告)号：NL2005733A

公开(公告)日：2011-06-09

申请号：NL2005733

申请日：2010-11-22

Applicant: ASML NETHERLANDS BV

Inventor： SETIJA IRWAN ,  KRAAIJ MARKUS ,  DIRKS REMCO ,  BEURDEN MARTIJN CONSTANT

IPC: G01N21/47 ,  G03F7/20

Abstract: Numerical calculation of electromagnetic scattering properties and structural parameters of periodic structures is disclosed. A reflection coefficient has a representation as a bilinear or sesquilinear form. Computations of reflection coefficients and their derivatives for a single outgoing direction can benefit from an adjoint-state variable. Because the linear operator is identical for all angles of incidence that contribute to the same outgoing wave direction, there exists a single adjoint-state variable that generates all reflection coefficients from all incident waves that contribute to the outgoing wave. This adjoint-state variable can be obtained by numerically solving a single linear system, whereas one otherwise would need to solve a number of linear systems equal to the number of angles of incidence.

公开(公告)号：NL2013312A

公开(公告)日：2015-03-10

申请号：NL2013312

申请日：2014-08-08

Applicant: ASML NETHERLANDS BV

Inventor： BEURDEN MARTIJN CONSTANT

IPC: G01N21/47 ,  G03F7/20

Abstract: A method of calculating electromagnetic scattering properties of a structure, the structure including materials of differing properties and the structure being periodic in at least one lateral direction and extending in a vertical direction, comprises: numerically solving a volume integral equation for electromagnetic scattering for a plurality of modes in the at least one lateral direction, by performing, for each respective mode, integration (1350) of a pseudo-spectral polynomial (Chebyshev) expansion in the vertical direction multiplied by a ID Green's function using the same sample points in the orthogonal direction for all of the plurality of modes. The integration is performed by solving a regularized linear system of equations between first (1116) and second (1120) discrete transformation steps to compute (1118) values of a regularized Chebyshev expansion coefficient vector (γ). Electromagnetic scattering properties of the structure are calculated using the results of the numerical solution.