Schottky barrier modulation on silicon nanowires

Oxide charge on the sidewalls of SiO2 embedded silicon wires with 20×20nm2 cross section is shown to influence the Schottky barrier height for Pd2Si∕Si junctions positioned on the end surfaces of the wires. Compared with results on planar silicon surfaces, the electron barrier height is 0.3eV lower for wires investigated as fabricated. By increasing the oxide charge through irradiation by ultraviolet light, the electron barrier decreases by an additional 0.15eV and the hole barrier correspondingly increases by about the same amount. The phenomenon is explained by assuming an oxide charge density in the range of 1012cm−2.