Patent ID: 7989923

Claim:
A semiconductor die, comprising: a semiconductor substrate of a first conductivity type having a substrate surface; an epitaxial layer formed on the substrate surface, the epitaxial layer having an epitaxial surface distal from the substrate surface; a buried layer of a second conductivity type selectively formed between the semiconductor substrate and the epitaxial layer, the buried layer having a buried surface distal from the substrate surface, the buried layer and the semiconductor substrate forming a first semiconductor junction; a first diffused region of the second conductivity type selectively formed on the substrate surface, the first diffused region extending from the epitaxial surface to the substrate surface, the first diffused region and the semiconductor substrate forming a second semiconductor junction; a second diffused region of the second conductivity type selectively formed on the buried surface, the second diffused region extending from the epitaxial surface to the buried surface; a third diffused region of the second conductivity type selectively formed in the first diffused region through the epitaxial surface; a fourth diffused region of the first conductivity type selectively formed in the third diffused region through the epitaxial surface, the fourth diffused region and the third diffused region forming a third semiconductor junction; and a fifth diffused region of the first conductivity type selectively formed in the second diffused region through the epitaxial surface, the fifth diffused region and the second diffused region forming a fourth semiconductor junction.