  The origin of the high leakage current measured in several vertical-type
diamond Schottky devices is conjointly investigated by conducting probe atomic
force microscopy (CP-AFM) and confocal micro-Raman/Photoluminescence (PL)
imaging analysis. Local areas characterized by a strong decrease of the local
resistance (5-6 orders of magnitude drop) with respect to their close
surrounding have been identified in several different regions of the sample
surface. The same local areas, also referenced as electrical hot-spots, reveal
a slightly constrained diamond lattice and three dominant Raman bands in the
low-wavenumber region (590, 914 and 1040 cm-1). These latter bands are usually
assigned to the vibrational modes involving boron impurities and its possible
complexes that can electrically act as traps for charge carriers. Local
current-voltage measurements performed at the hot-spots point out a
trap-filled-limited (TFL) current as the main conduction mechanism favoring the
leakage current in the Schottky devices.
