Characterization and passivation of band gap states in metal-oxide-semiconductor field effect transistors with polycrystalline silicon channel

High density of states in energy bandgap causes low carrier mobility and poor reliability in devices with poly-Si channel. Trap state densities of poly-Si devices in grain boundary and at dielectric interface were evaluated using Meyer-Neldel rule and charge pumping method. It was found that H₂ high pressure anneal was very effective in passivating both trap states in grain boundary and at dielectric interface. The passivation of traps leads to significant improvement of performance and device reliability.