INFLUENCE OF ELECTRON-SCATTERING ON CURRENT INSTABILITY IN-FIELD EFFECT TRANSISTORS

We consider the influence of scattering of carriers on the ''shallow w ater wave instability'' of surface plasma waves in a ballistic field e ffect transistor. Scattering (which is analogous to friction in a shal low water channel) leads to a strongly non-uniform potential distribut ion in the channel and reduces the increment of the instability. At a certain critical value of friction, the instability vanishes. The inst ability increment also depends on the drain current. The analysis of t hese dependencies for the samples with different carrier mobilities an d different dimensions allows us to determine the operating regimes re quired for the observation of the instability. Our computer simulation s confirm these analytical results. (C) 1998 Elsevier Science Ltd. All rights reserved.