Leakage currents occur through several mechanisms: 1. Direct Tunneling: In thin insulators, electrons can tunnel directly through the barrier. 2. Fowler-Nordheim Tunneling: At higher electric fields, electrons tunnel through a triangular barrier. 3. Thermionic Emission: Electrons gain enough thermal energy to overcome the potential barrier. 4. Trap-Assisted Tunneling: Electrons use defect states within the insulator to hop across the barrier.
