Near band edge Schottky barrier height modulation using high-κ dielectric dipole tuning mechanism

Abstract

Schottky barrier height tuning using high-κ/SiO2 interfacial dipoles is reported. Schottky barrier heights of 1.0 and 0.2 eV are observed in a TaN/p-Si diode by insertion of thin layers of high-κ (LaOx,AlOx) and SiO2 at the metal-semiconductor interface. The dipole tunes the effective work function of TaN/p-Si by more than 0.8 eV to achieve effective Schottky barrier heights near conduction and valence band edge. LaOx (n-type) and AlOx (p-type) have a dipole potential offsets estimated to be 0.3 and 0.5 V, respectively. Applications to lowering contact resistivity are discussed, as well as a comparison of other dipole offsets.