Esd protection device for enhancing reliability and for providing control of esd trigger voltage

A semiconductor device formed in a semiconductor substrate for protecting against electrostatic discharge comprising:

• a first region of a first conductivity type formed in said substrate, said first region having a first dopant concentration;
• a second region of said first conductivity type formed in said first region and said substrate, said second region having a dopant concentration greater than said first dopant concentration, said second region being coupled to an input pad of an integrated circuit;
• a first well of a second conductivity type formed in said substrate and adjacent said first and second regions;
• a third region of said second conductivity type formed in said first well and underneath said first region, said third region having a dopant concentration greater than a dopant concentration of said first well;
• a fourth region of said first conductivity type formed in said first well and being connected to a reference voltage, said fourth region having a dopant concentration greater than said dopant concentration of said first well;
• and
• a fifth region of said second conductivity type formed in said first well and being connected to said reference voltage, said fifth region having a dopant concentration greater than said dopant concentration of said first well;
• wherein said first region and said first well forms the p-n junction of a trigger diode, and said first region forms a collector region, said first well and said third region form a base and said fourth region forms an emitter region of an NPN transistor.

A diode-triggered bipolar transistor ESD protection device, comprising:

• a diode comprising a junction of a p-type semiconductor material and an n-type semiconductor material, an anode of said diode being coupled to a reference voltage and a cathode of said diode being coupled to a pad of an integrated circuit;
• and
• a transistor having a first current handling terminal coupled to said pad, a second current handling terminal coupled to said reference voltage, and a control terminal coupled to said anode of said diode;
• wherein said junction of said diode comprises a shaped periphery, said diode providing reverse-biased breakdown current to said transistor when a voltage at said pad exceeds a breakdown voltage of said diode.

A diode-triggered ESD protection device, comprising:

• a diode comprising a junction of a p-type semiconductor material and an n-type semiconductor material, an anode of said diode being coupled to a reference voltage and a cathode of said diode being coupled to a pad of an integrated circuit;
• and
• a silicon controlled rectifier having an anode coupled to said pad, a cathode coupled to said reference voltage;
• wherein said junction of said diode comprises a shaped periphery, said diode providing reverse-biased breakdown current to turn on said silicon controlled rectifier when a voltage at said pad exceeds a breakdown voltage of said diode.