Abstract: A method for accurately calculating the movement of a vertex in a three-dimensional (3-D) topography simulator. The method is particularly suited for calculating vertex movement for cases in which etch/deposition rate depends on the angle between the surface normal and the vertical direction. A workpiece is represented as a collection of material solids. Each of the material solids has a boundary model representation. The method of the present invention is comprised primarily of the steps of: advancing edges and surface planes adjacent to the vertex, creating a set of 2-D solutions by clipping with pairs of adjacent surface planes; creating a set of combined 2-D solutions by clipping invalid sections of combined 2-D solutions; construct an arbitrary vertical plane that intersects the surface at the vertex point; constructing vertex trajectories for the vertex to be moved; and clipping constructed vertex trajectories at intersections of created surface and the constructed vertical plane.

Abstract: A method for creating regular triangular grid representations of a solid surface from a representation comprised of a plurality of polygons. Such a regular grid is necessary in order to accurately deform a solid during simulation of a process step. The method of the preferred embodiment is comprised generally of the steps of: removing any holes defined by the polygon face; placing a new edge between a first and second vertex of the polygon face; discarding the new edge if the new edge lies outside the polygon face or if the new edge intersects an existing edge of the polygon face; adding the new edge to the polygon face if the new edge does not lie outside the polygon face; identifying a triangle being created by the new edge and existing edges of the polygon; forming a new polygon face from the edges creating a triangle; and repeating the above steps until all polygon faces are triangulated.

Abstract: In a three-dimensional (3-D) topography simulator, a method for removing sources of particle flux because of neighboring topology, for a point on a workpiece undergoing a deposition or etch process step. The method is practiced in a Generalized Solids Modeling system that utilizes a boundary representation model for representing a workpiece as one or more material object solids. For any given point on the 3-D structure, the neighboring topography forms a complex shadowing mask with respect to sources of particle flux, thus making analytical determination of visible sources of incoming particle flux difficult. The method is comprised generally of the steps of: defining a numerical mesh in a space over a surface of the workpiece; specifying an intensity of incident flux for each mesh point, identifying a set of mesh points defining a visible range of mesh points with respect to a particular target point and identifying mesh points in said set of mesh points that are obscured by neighboring topology.