Can someone explain how sub threshold leakage happens physically. Even when the voltage is zero, there is some amount of Ioff current, hows it possible?
When Vgs is zero, there is no channel formed. When there is some potential difference across drain and source, the psub (in case of NMOS and nwell in case of PMOS) just conducts or leaks some charges depending on its conductivity or doping. It just acts as a very high resistance.
Hi,
Hope u know how the channel is formed in the transistor with applying gate voltage.Lets take a NMOS when u go on increasing the gate voltage more and more electrons start accumulating below the gate.So at very low voltages also there are small number of electrons present which make the reason for subthreshold current which is the reason for leakages.