We present the solution of the Boltzmann equation for relatively low densit
y gated two-dimensional electron gas where electron-electron collisions are
not significant. This solution describes the plasma waves with the same di
spersion law as for a high electron sheet density. In both cases, the plasm
a waves become instable in a short channel field effect transistor with asy
mmetric boundary conditions at small channel currents (provided that the sc
attering by phonons and impurity is sufficiently small). Our analysis also
shows that for realistic values of the device parameters, the Landau dampin
g is small. (C) 2001 American Institute of Physics.