US 11,837,600 B2
Electrostatic discharge protection apparatus and its operating method
Wen-Tsung Huang, Changhua County (TW); Shih-Yu Wang, Taipei (TW); and Chih-Wei Hsu, Changhua County (TW)
Assigned to MACRONIX INTERNATIONAL CO., LTD., Hsinchu (TW)
Filed by MACRONIX INTERNATIONAL CO., LTD., Hsinchu (TW)
Filed on Nov. 15, 2021, as Appl. No. 17/526,014.
Prior Publication US 2023/0154920 A1, May 18, 2023
Int. Cl. H01L 27/02 (2006.01); H01L 29/74 (2006.01)
CPC H01L 27/0262 (2013.01) [H01L 29/7436 (2013.01)] 10 Claims
OG exemplary drawing
 
1. An electrostatic discharge protection apparatus, comprising:
a substrate;
a first well having a first conductivity type and disposed in the substrate;
a second well having a second conductivity type and disposed in the first well;
a first doping region having the first conductivity type and disposed in the second well;
a second doping region having the first conductivity type and disposed in the second well;
a third doping region having the second conductivity type and disposed in the second well; and
a fourth doping region having the first conductivity type and disposed in the substrate,
wherein the first conductivity type is different from the second conductivity type; the second well, the first well, the substrate and the fourth doping region form a silicon controlled rectifier; electrostatic discharge current flowing into the first doping region flows to the fourth doping region through the silicon controlled rectifier.