Semi Greedy Algorithm for Finding Connectivity in Microchip Physical Layouts

Scan based or Line Sweep methods are a traditional mechanism to traverse the physical layout, or artwork of a microchip. These traversals are incremental in nature. They typically traverse the artwork from bottom to top (in the y direction) and from left to right (in the x direction) in a traditional Cartesian plane. As the traversal occurs, client applications need to know what causes a given event. For example, an analysis algorithm may be interested in finding out every time two rectangle shapes overlap or touch. This is important because such an overlap could represent a short in a circuit. The number of rectangles used to represent real world designs of artwork in a microchip is in the order of one million per metal layer, thus various optimization techniques are necessary to breakdown the complexity of such designs. This paper describes a semi-greedy technique coupled with an object oriented design pattern to aid in traversing and reporting events of chip data.