Impact of poly-gate depletion on MOS RF linearity

The distortion behavior for thin oxide MOS transistors can be degraded due to polysilicon-gate depletion effects. The nonlinear, bias-dependent gate capacitance for thin oxide MOSFETʹs results in significant 2nd-order derivatives in gate capacitance, (.../sup 2/C(V/sub gs/)/...V/sub gs//sup 2/), which in turn results in substantial 3rd-order derivative contributions to drain current, (.../sup 3/I/sub ds//...V/sub gs//sup 3/). This may restrict the use of very-thin oxide MOSFETʹs in RF applications.