Schottky barrier modulation on silicon nanowires

摘要

Oxide charge on the sidewalk of SiO_2 embedded silicon wires with 20 X 20 nm~2 cross section is shown to influence the Schottky barrier height for Pd_2Si/Si junctions positioned on the end surfaces of the wires. Compared with results on planar silicon surfaces, the electron barrier height is 0.3 eV lower for wires investigated as fabricated. By increasing the oxide charge through irradiation by ultraviolet light, the electron barrier decreases by an additional 0.15 eV 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 10~(12) cm~(-2).