Quantitative Assessment of Wiring Layout Quality

Abstract:
Although conductor shapes serve many purposes in an integrated circuit-like building capacitors, pads, coils, etc.-, the majority of those shapes is typically used for wiring that is connecting circuit elements according to required functionality. In particular, this is the case in the routing layers of synthesized standard cell blocks. Quality assessment of such wiring layout is necessary for comparison of router tools and setups, detection of improvement potentials, definition of corresponding activities; and last not least for measurement and improvement of the efficiency of post-routing operations such as wire spreading and fattening. In this paper, we propose a methodology for quantitative, accurate, and detailed assessment of wiring layout quality mainly considering defect limited yield aspects. Essentially, we perform area resolved Critical Area Analysis of a layout and compare the actual figures to a set of "what-if" or reference scenarios. Examples will illustrate the concept and its practical application.