Temperature Inversion

In Current equation, I = K.μ.( VGS - VTH)2 ; where mobility (μ) and Threshold Voltage (VTH) are functions of Temperature

At high voltage μ determines the Drain current where as at lower voltages VTH determines the drain current. So at higher voltages device delay increase with temperature but at lower voltages, device delay decreases with temperature

At advanced Technology Nodes though the Threshold Voltage has not reduced much, but the Gate Overdrive Voltage has reduced due to the reduction of supply voltages

Temperature Inversion Effects are more observed in Technology Nodes below 40nm