  We report low frequency tunnel current noise characteristics of an organic
monolayer tunnel junction. The measured devices, n-Si/alkyl chain (C18H37)/Al
junctions, exhibit a clear 1/ f &#947; power spectrum noise with 1< &#947;
<1.2. We observe a slight bias-dependent background of the normalized current
noise power spectrum (SI/I^2). However, a local increase is also observed over
a certain bias range, mainly if V > 0.4 V, with an amplitude varying from
device to device. We attribute this effect to an energy-dependent trap-induced
tunnel current. We find that the background noise, SI, scales with >. A model
is proposed showing qualitative agreements with our experimental data.
