每日一奖----20140509

damonzhao

Q4. Which layer is used for clock routing and why?

jinwei91

M5 ~ (top layer -2) maybe suitable.
Utilization of metals below M5 used for signal route maybe very high, if used to route clock, may cause some violations. Also, higher metals have low resistance(higher width, higher thickness) and the performance maybe better.

top layer -2 ~ top metal is better to be used for power route.