Patent ID: 9711499
Date: 2017-07-18
CPC Classifications: H01L

Claim:
1. A method of providing electrostatic discharge protection to a semiconductor device, comprising: providing a first semiconductor region of a first conductivity type; forming a Zener diode on a first portion of the first semiconductor region; forming a first PN diode on the Zener diode, the first PN diode comprising a portion of a second semiconductor region of a second conductivity type overlying the first semiconductor region, and a fourth semiconductor region of the first conductivity type overlying the second semiconductor region; forming a second PN diode on a second portion of the first semiconductor region adjacent to the first portion, the second PN diode having a cathode side in electrical contact with the first semiconductor region; forming an insulating layer over the first and second PN diodes; forming a first opening extending through the insulating layer to expose a portion of a surface of the fourth semiconductor region; and forming a second opening extending through the insulating layer to contact the second diode, wherein the ratio of the area of the surface of the fourth semiconductor region exposed by first opening to the total area of the surface of the fourth semiconductor region is greater than or equal to ten percent and less than or equal to ninety percent.