Modulation of CoSi2/Si Schottky barrier height by charge transfer doping utilizing cesium segregation at the SiO2/Si interface

We demonstrate that the Schottky barrier height (SBH) Of CoSi2/n-Si diodes is efficiently modulated by charge transfer doping from the implanted Cs ions segregated at the SiO2/Si interface. The current-voltage characteristics and their temperature dependence revealed that the SBH reduced from the initial 0.52 to 0.06 eV with a Cs dose of 5 x 10(13) cm(-2) and to the ohmic feature for a dose exceeding 5 x 10(14) cm(-2). This SBH reduction is attributed to barrier thinning and image-force barrier lowering resulting from band bending due to the positive Cs ions segregated at the SiO2/Si interface above the CoSi2 contact.