A logic cell, for use in a semicustom chip, is comprised of a plurality of transistors that are integrated into a semiconductor substrate and are interconnected within the cell to perform a logic function. This cell has sidewalls which define the space in the chip which contains all the transistors and...http://www.google.ca/patents/US4949149?utm_source=gb-gplus-sharePatent US4949149 - Semicustom chip whose logic cells have narrow tops and wide bottoms
