Patent ID: 8759871

Claim:
An electrostatic discharge (ESD) protection structure comprising: a first semiconductor structure comprising: a first semiconductor substrate of a first conductivity type, a first well of the first conductivity type formed into the first semiconductor substrate, a second well of a second conductivity type formed into the first semiconductor substrate adjacent to the first well, an intersection of the first and second wells forming a p-n junction, a first diffused region of the first conductivity type formed at the surface of the second well and electrically coupled to a positive power supply terminal, a second diffused region of the second conductivity type formed at the surface of the first well and electrically coupled to a pad terminal, and a third diffused region of the first conductivity type formed at the surface of the first well and electrically coupled to a ground terminal; and a second semiconductor structure comprising: a second semiconductor substrate of the first conductivity type, a third well of the first conductivity type formed into the second semiconductor substrate, a fourth well of the second conductivity type formed into the second semiconductor substrate adjacent to the first well, an intersection of the first and second wells forming a p-n junction, a fourth diffused region of the second conductivity type formed at the surface of the fourth well and electrically coupled to the positive power supply terminal, a fifth diffused region of the first conductivity type formed at the surface of the fourth well and electrically coupled to the pad terminal, and a sixth diffused region of the second conductivity type formed at the surface of the third well and electrically coupled to the ground terminal; an RC power clamp circuit coupled between the positive power supply terminal and the ground terminal; and at least one conductor configured to selectively provide an electrical path at least partially between one of the diffused regions of the first conductivity type, formed at the surface of one of the wells of the second conductivity type, and one of the diffused regions of the second conductivity type, formed at the surface of one of the wells of the first conductivity type, via said one well of the first conductivity type and said one well of the second conductivity type.