Patent ID: 9691752
Date: 2017-06-27
CPC Classifications: H01L

Claim:
1. An electrostatic discharge (ESD) protection device, comprising: a substrate; a first doped well disposed in the substrate and having a first conductive type; a drain region disposed in the first doped well and having a second conductive type; a guard ring disposed in the first doped well and having the first conductive type, the guard ring surrounded the drain region and having a first portion extending along a first direction and a second portion extending along a second direction different from the first direction; a first source region disposed in the first doped well and between the drain region and the first portion of the guard ring, the first source region having the second conductive type; and a second doped well disposed in the first doped well between the drain region and the second portion of the guard ring, the second doped well having the second conductive type, wherein the second doped well is in contact with the drain region and is disposed at least partially outside the drain region in the first direction.