HOT-CARRIER FLUCTUATIONS FROM BALLISTIC TO DIFFUSIVE REGIME IN SUBMICRON SEMICONDUCTOR STRUCTURES

We present a theoretical analysis of number and current fluctuations i n homogeneous n-Si resistors of submicron dimensions at increasing ele ctric field strengths. To this purpose, we calculate the corresponding correlation functions. In the ballistic regime a simple scaling relat ionship of the transit time accounting for carrier heating is found to hold over the whole range of fields considered. In the diffusive regi me different time scales associated with diffusion, drift and dielectr ic relaxation are found to characterize the behaviour of number fluctu ations.