ISOLATION TECHNIQUE ALLOWING BOTH VERY HIGH AND LOW VOLTAGE CIRCUITS TO BE FABRICATED ON THE SAME CHIP

摘要

An integrated circuit (IC) fabrication technique is provided for isolating very high voltage (1000 s of volts) circuitry and low voltage circuitry formed on the same semiconductor die. Silicon-on-Insulator (SOI) technology is combined with a pair of adjacent backside high voltage isolation trenches that are fabricated to be wide enough to stand off voltages in excess of 1000V. The lateral trench is fabricated at two levels: the active silicon level and at the wafer backside in the SOI bulk.