Wires
CE-653 - Introduction and Fundamentals
12
}Pitch = w + s
}Aspect ratio = t/w
}Old processes had AR<<1
}Modern processes AR~2
}Under scaling:
}Narrower and thinner
}Wiring layers are closer
}Wires are drawn closer
}
However, not everything scales well.  Wires used to contribute negligible delay but each process generation they actually got worse--excepting certain changes such as low-k dielectrics, copper instead of aluminum.
Narrower and Thinner => Higher resistance per unit length