The minority-carrier injection-controlled field-effect transistor (MICFET)

A three-terminal power field-effect transistor structure that has a switching speed close to that for the power MOSFET with 30% higher on-state current density is described. The device structure is similar to that for the power MOSFET with the addition of a floating injector region whose potential can be controlled by an integrated vertical DMOSFET. The n-channel MICFET structure was fabricated with a standard polysilicon gate DMOSFET process using 20- Omega -cm, 40- mu m-thick epitaxial n-type layers grown on (0.02 Omega pd cm) n/sup +/ substrates. The devices had a p-base of 3 mu m and an n/sup +/ source depth of 1 mu m. The breakdown voltages of the MICFET and DMOSFET were both in excess of 500 V.