oTemperature Inversion effect is seen at lower technology nodes (28nm and below), where cell delay is inversely proportional to the temperature. This is mainly because of reduced supply voltage at lower nodes.
- Cell delay depends on carrier mobility and threshold voltage of transistor. Both mobility and threshold voltage inversely proportional to the temperature.
- At higher nodes, due to high supply voltage, effect of mobility is dominant over threshold voltage on cell delay. So, As temperature increases, mobility decreasesand cell delay increases.
- While at lower nodes, as supply voltage is reducing, effect of threshold voltage is dominant on cell delay compared to mobility. So, As temperature increases, threshold voltage decreases and cell delay decreases