Hydrogenated diamond surfaces studied by atomic and Kelvin force microscopy

Atomic force (AFM) and Kelvin force microscopy (KFM) are employed to characterize and modify both morphologic and electronic properties of (100) hydrogenated diamond surfaces with high lateral resolution. Contrasts in AFM and KFM images are discussed and values of the local surface work function and Fermi level are deduced using gold and aluminum pads. A shift of Fermi level is observed by KFM during sample illumination, in agreement with an increase in conductivity. Using negatively biased cantilevers in AFM, surface hydrogen termination of diamond is locally removed with a resolution of 10 nm. Thus insulating nanoscale patterns are scribed into the diamond surface. Conductivity through such patterns is orders of magnitude lower than for H-terminated diamond.