High frequency switch circuit device

摘要

A high frequency switch circuit device includes an FET to be a switching element on a semiconductor substrate. The FET includes an n-type well, a gate electrode, a source layer and a drain layer. An n-type well line to be connected to an n-type well layer to be a back gate is connected to a voltage supply node via an inductor. The flow of a high frequency signal between the voltage supply node and the n-type well layer is blocked by the inductor, and the flow of a high frequency signal in the vertical direction is blocked by a depletion layer extending between the n-type well and a p-type substrate region. Moreover, the flow of a high frequency signal in the horizontal direction is blocked by a trench separation insulative layer.