Enhancing capacitance of dielectric Si-oxide film by inserting indium-tin-oxide interlayer

Two parallel-plate capacitors, Cu/Si-oxide/Cu (MIM) and Cu/Si-oxide/indium-tin-oxide/Cu (MIM-ITO), were fabricated. The capacitance of MIM-ITO structure (1365.5 pF) was measured to be much larger than MIM structure (442 pF) by two folds. The ITO interlayer enhances the ‘edge effect’ and results in non-stoichiometric Si₂O₃ phase formation in Si-oxide film. Si₂O₃ tetrahedrons present strong spontaneous dipoles, which result in an additional net polarization in the Si-oxide film under an applied electric field. With TEM images, (222)-preferred ITO crystalline phase was observed at the Si-oxide/ITO interface and served as the growth seed layer for Si₂O₃-contained Si-oxide film.