Conductance fluctuations in large metal-oxide-semiconductor structures in the variable-range hopping regime

Conductance fluctuations due to variable-range hopping have been studied in 8-mm-wide silicon inversion layers of large area (3.2 ${\mathrm{mm}}^2$). The temperature dependence of the average logarithm of conductance 〈lnG〉 varies with the carrier density ${\mathit{N}}_{\mathit{s}}$ from nearly activated to very weak. Fluctuations of lnG with the chemical potential μ occur on two different scales. The distribution function of the fluctuations in lnG is also analyzed, and the results are consistent with the model of conduction via exponentially rare, highly conducting, quasi-one-dimensional chains of hops.