Complementary bipolar and MOS transistor having power and logic structures on the same integrated circuit substrate

An integrated circuit device of a first N-type epitaxial layer over a substrate, a second P-type epitaxial layer over the first epitaxial layer, and a third N-type epitaxial layer over the second epitaxial layer, with a P-type buried ground region formed in a portion of the substrate, the ground region extending from the substrate to the third epitaxial layer in a first tank region and extending through the first and second epitaxial layers. A power bipolar transistor is formed in the first tank region. P isolation areas extending from the surface of the third epitaxial layer to the P ground region isolate the bipolar transistor from other tank region on the same substrate in which N and P channel MOSFETS are formed.