Book: Introduction to VLSI Circuits and Systems, John P. Uyemura page: 101 - Han-Jen Yang Error: Figure 3.34(b) This is a minor error on printing/diagram lining up. On the layout diagram, the metal is not having a direct via/contact with the second poly (the poly for the second inverter). The metal wire is supposed to extend right over the poly. If this layout is used to make an actual IC, the chip will be faulty and material will be wasted.