MOS ESD CDM clamp with integral substrate injection guardring and method for fabrication

摘要

The present invention includes a MOS device ( 100 ) that has a P-type substrate ( 102 ) and an N-type drain region ( 104 ) formed within the substrate ( 102 ). An annular N-type source region ( 106 ) generally surrounds the drain region ( 104 ). The source region ( 106 ) serves as both the source for the MOS device ( 100 ) and a sacrificial collector guard ring for an electrostatic discharge protection circuit. An annular gate region ( 110 ) generally surrounds the drain region ( 104 ) and is electrically insulated from the drain region ( 104 ) and electrically connected to the source region ( 106 ). An annular P-type bulk region ( 108 ) generally surrounds the source region ( 106 ) and is electrically connected to the source region ( 106 ).