Nanoscale modification of electrical properties of hydrogenated boron-doped diamond

Local modification at the nanometre scale of the electrical (I-V) and electron field emission (FE) properties of boron-doped hydrogenated diamond are reported. These are achieved by the application of a voltage pulse between the hydrogenated diamond surface and the tip of a scanning tunnelling microscope under UHV conditions. The area affected by the voltage pulse (2-4 nm in diameter) shows a drastic reduction in tunnelling current (by 2 orders of magnitude) and a concomitant decrease in field emission. The tunnelling current and field emission properties gradually recover on a time scale of about 1 hour under UHV conditions. These surface modifications are thought to be due to hydrogen removal that is caused by the voltage pulse. The observed recovery appears to be due to H replenishment which restores the surface conductivity and negative electron affinity of the surface. (C) 2004 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.