ESD structure without ballasting resistors

• Main Authors: Lin, Shu Huei, Lee, Jian Hsing, Huang, Shao Chang, Wu, Cheng Hsu, Lee, Chuan Ying
• Format: Patent
• Language: English
• Published: 28.07.2009

An electrostatic discharge (ESD) structure connected to a bonding pad in an integrated circuit comprising: a P-type substrate with one or more first P+ regions connected to a low voltage supply (GND), a first Nwell formed in the P-type substrate, one or more second P+ regions disposed inside the first Nwell and connected to the bonding pad, at least one first N+ region disposed outside the first Nwell but in the P-type substrate and connected to the GND, at least one second N+ region disposed outside the first Nwell but in the P-type substrate and connected to the bonding pad, wherein the second N+ region is farther away from the first Nwell than the first N+ region, and at least one conductive material disposed above the P-type substrate between the first and second N+ regions and coupled to the GND, wherein the first N+ region, the second N+ region and the conductive material form the source, drain and gate of an NMOS transistor, respectively, and the first P+ region is farther away from the first Nwell than the NMOS transistor.