Abstract: A high voltage PMOS device having an improved breakdown voltage is achieved. An asymmetrical high voltage integrated circuit structure comprises a gate electrode on a substrate and source and drain regions within the substrate on either side and adjacent to the gate electrode wherein the source region is encompassed by an n-well. A symmetrical high voltage integrated circuit structure comprises a gate electrode on a substrate, source and drain regions within the substrate on either side and adjacent to the gate electrode, and an n-well in the substrate underlying the gate electrode. The n-well in both structures shifts the breakdown point from the silicon surface to the bottom of the source or drain regions.

Abstract: A high voltage PMOS device having an improved breakdown voltage is achieved. An asymmetrical high voltage integrated circuit structure comprises a gate electrode on a substrate and source and drain regions within the substrate on either side and adjacent to the gate electrode wherein the source region is encompassed by an n-well. A symmetrical high voltage integrated circuit structure comprises a gate electrode on a substrate, source and drain regions within the substrate on either side and adjacent to the gate electrode, and an n-well in the substrate underlying the gate electrode. The n-well in both structures shifts the breakdown point from the silicon surface to the bottom of the source or drain regions.