1. Field of the Invention
The present invention relates generally to integrated circuits and more particularly to high power, voltage isolated integrated circuits having IGFET and bipolar transistors therein.
2. Description of the Prior Art
Insulated gate field effect transistors (IGFET), and especially metal oxide field effect transistors (MOS) are very desirable elements in integrated circuits because of their low power dissipation and relatively simple fabrication. However, the low transconductance and limited current capacity of MOS devices preclude their use in many applications. Addition of bipolar transistors in junction isolated circuits with IGFETs have been used to decrease the switching time and as protective devices. The junction isolated integrated circuits of the prior art, including IFGETs and bipolar transistors, do not provide devices with high breakdown voltages, i.e., breakdown voltages greater than 30 volts. Similarly, the process of fabrication in these prior art isolated integrated circuits have generally been quite complex and expensive. Thus there exists a need for a junction isolated integrated circuit having IGFETs and bipolar transistors with high breakdown voltages and which may be fabricated using a minimum number of processing steps.