The mechanism of an anomalous leakage current in mesa-isolated SOI NMO
SFET's in the short-channel region was analyzed, The enhanced diffusio
n of the source-drain impurities was observed in the mesa edge region
by Energy Dispersive X-ray Spectroscopy (EDX) analysis, Moreover, usin
g high-resolution TEM observation, it was found that there were no cry
stalline defects in the edge region, The frequency of leakage currents
in short-channel MOSFET's was higher than that of long-channel MOSFET
's. The level of leakage current was not changed by the gate voltage a
nd back gate voltage, and the activation energy of the leakage current
was almost 0 eV, According to these results, it is concluded that the
origin of the anomalous Leakage current is the enhanced diffusion of
source-drain impurities.