Shot-noise suppression in Schottky barrier diodes

We give a theoretical interpretation of the noise properties of Schottky ba rrier diodes based on the role played by the long range Coulomb interaction . We show that at low bias Schottky diodes display shot noise because the p resence of the depletion layer makes the effects of the Coulomb interaction negligible on the current fluctuations. When the device passes from barrie r to flat band conditions, the Coulomb interaction becomes active, thus int roducing correlation between different current fluctuations. Therefore, the crossover between shot and thermal noise represents the suppression due to long range Coulomb interaction of the otherwise full shot noise. Similar i deas can be used to interpret the noise properties of other semiconductor d evices. (C) 2000 American Institute of Physics. [S0021- 8979(00)03418-6].