Abstract: A power integrated circuit includes a substrate with an overlying epitaxial surface layer of opposite conductivity type. A semiconductor power device, such as a high-power diode or lateral MOS transistor, is located in the epitaxial layer and forms a p-n junction diode with the substrate. The power integrated circuit also includes a separate semiconductor well region in the epitaxial layer, in which one or more low-power semiconductor circuit elements are formed. In order to minimize the problem of latch up in the low-power circuit elements due to the injection of minority carriers from the substrate, the power integrated circuit is provided with a collector region and an isolation region between the power device and the well region having the low-power circuit elements.

Abstract: A lateral trench-gate bipolar transistor device includes spaced-apart, surface-adjoining, laterally-oriented anode and cathode regions. A channel region at least partially surrounds the cathode region, and a gate region is provided adjacent to, but insulated from, the cathode region and the channel region. The gate region extends in a substantially vertical direction adjacent the cathode region and the channel region in order to induce a substantially vertical conduction channel in the channel region of the lateral device during operation. The gate region can advantageously be provided in a trench surrounding the transistor device, with a trench-shaped gate dielectric layer being provided on the trench sidewalls and floor to insulate the gate from the remainder of the device. Devices may be fabricated in an epitaxial surface layer, which may be provided either directly on a semiconductor substrate, or else on an intervening insulating layer.