Abstract: Polysilicon in a trench is etched at an angle to produce a conductor within the trench that has shape characteristics which approximate the shadow of the side wall of the trench closest the beam source. Specifically, when the first side wall is closest to the beam source and the second side wall is furthest from the beam source, the polysilicon on the first side wall is almost as high as the first side wall, while the polysilicon on the more exposed side wall is considerably lower than the first side wall and approximates the shadow of the first side wall on the second side wall relative to the beam. The polysilicon in the trench may be in the shape of a solid angled block approximating the shadow line from the top of side wall to the shadow line on side wall however, it is preferred that the polysilicon take the form of a conformal layer in trench prior to etching such that the polysilicon ultimately has an angled "U" shape which approximates the shadow line.

Abstract: A computer based system and method is provided for generating a design verification scheme for a hierarchical circuit design. A set of directives received describing design checks to be performed on a hierarchical circuit design. The directives are functionally decomposed into primitive functions required to perform them. A primary iteration level is established for each directive, and a data flow dependency is determined for the directives. Based on the data now dependency, a sequence or operations is organized. The operations are optimized in one or more ways to improve the efficiency of the design verification process. The optimized operations are coded into an application program which executes in a computer processor. The application program accesses the VLSI circuit design under review and performs the directives using the data structures allocated during schema generation.