An integrated circuit device having improved substrate capacitance isolation.

摘要

An integrated circuit device having improved substrate capacitance isolation for use in a ultra low capacitance probe or an input to an oscilloscope or the like has an electrically conductive layer formed directly underneath an input node on the integrated circuit. The electrically conductive layer has a geometry substantially equal to the input node and in driven by a voltage output from a high impedance unity gain circuit. In one embodiment, the electrically conductive layer is formed in the first metal layer of the integrated circuit while an alternate embodiment an emitter region of a semiconductor device in the high impedance circuit is used as the electrically conductive layer.