Patent ID: 6576958
Filing Date: 2003-06-10
Classification: H01L

Abstract:
An electrostatic discharge (ESD) protection circuit, for application on an integrated circuit (IC) chip, comprising a diode, the diode comprising:a first semiconductor layer of a first conductivity type, used as a first electrode; and a MOS transistor of a second conductivity type, comprising: a circular gate, located in insulation on the first semiconductor layer; a first source/drain diffusion of the second conductivity type, formed on the first semiconductor layer enclosed by the circular gate, as a second electrode; and a second source/drain diffusion of the second conductivity type, formed on the first semiconductor layer, and enclosing the circular gate, wherein one of the first electrode and the second electrode is the cathode of the diode, coupled to a first pad, and one of said first electrode and said second electrode is the anode of said diode, coupled to a second pad.