Local transport and trapping issues in Al₂O₃ gate oxide structures

The bias dependence of interfacial barriers in Al2O3-based metal-oxide-semiconductor structures was studied by ballistic electron emission spectroscopy. Strong image force reductions of the barriers were observed. A conduction band offset between Al2O3 and Si of 2.78 eV was obtained. Electron trapping into levels that overlap the Si band gap and are located near the Si-Al2O3 interface led to charge densities of ∼2.5 × 1012cm-2. © 2000 American Institute of Physics.