Poly-silicon logic for integration of drive, sense and protection functions in discrete power devices

Polysilicon is usually used as a gate material for MOS-gated power devices and can also be used for the fabrication of active components. These components can be integrated on the surface of semiconductor devices, which are dielectrically insulated by a thermal field oxide. This paper describes the application of this technology to a test field of various active and passive devices as well as analog and 15 V elementary logic circuits. It is possible to fabricate analog and digital circuits by including these results in the design process. This therefore provides an inexpensive and easy way to add diagnostic, monitoring and protection functions to power devices, especially high voltage MOSFETs and IGBTs.