Patent ID: 7805700

Claim:
A computer-implemented method for determining a surface associated with a resist profile in a material, comprising: calculating, using a computer, arrival times of a wavefront in a resist-development process at a first depth in the material in accordance with an Eikonal equation, wherein the first depth is proximate to an outer surface of the material, and wherein a vector development rate in the Eikonal equation corresponds to a physical property of the material; calculating arrival times of the wavefront at a second depth in the material, which relative to the first depth is distal from the outer surface, in accordance with the Eikonal equation and the calculated arrival times at the first depth; determining, using a fast-sweeping calculation, the surface associated with the resist profile in the material based on the calculated arrival times at the first depth, the calculated arrival times at the second depth, and a given time interval, wherein arrival times at a given depth in the material, which includes the first depth or the second depth, are calculated by directly determining a steady-state solution of the Eikonal equation; wherein the calculation at the given depth, which is either or both of the first depth and the second depth, includes sweeping over the first set of values along a first direction in a plane associated with the given depth, and sweeping over a second set of values along a second direction in the plane; and wherein the sweeping over a given set of values, which is either or both of the first set of values and the second set of values, includes sweeping from low-to-high values and sweeping from high-to-low values.