US Patent 8492220 Vertically stacked FETs with series bipolar junction transistor

Vertically stacked Field Effect Transistors (FETs) are created on a vertical structure formed on a semiconductor substrate where a first FET and a second FET are controllable independently. A bipolar junction transistor is connected between and in series with the first FET and the second FET, the bipolar junction transistor may be controllable independently of the first and second FET.