Factors Behind Device Delay

Device speed is directly related to:

• The width of the device.
• The clock slew rate.
• The load capacitance.

KEY Device delay depends on device width, clock slew rate and load capacitance.

Temperature Inversion

At older (larger) CMOS technologies, cell delay increases as temperature rises. But at smaller nodes - roughly below 65nm - the relationship inverts: cell delay becomes inversely proportional to temperature.

KEY Temperature inversion: below ~65nm, cell delay decreases as temperature increases.

Higher Fanout and Delay

Higher fan-out adds more capacitive load on the driving gate, which increases its propagation delay.

KEY More fan-out means more load on the driver, so propagation delay increases.