Thick gate oxide transistor and electrostatic discharge protection utilizing thick gate oxide transistors

Abstract

An electrostatic discharge (ESD) protection circuit that includes an transistor with a gate electrode isolated from the semiconductor substrate. The transistor can be an insulated gate bipolar transistor (IGBT) connected between an integrated circuit (IC) pad and ground. The IGBT includes a parasitic thyristor that latches when the voltage at the pad exceeds a threshold level and does not turn off until the charge at the pad is dissipated, thereby preventing electrostatic damage to the IC.

1 . An insulated gate bipolar transistor (IGBT) in an integrated circuit, the IGBT comprising: 
 a gate, an emitter and a collector,    wherein the gate comprises a gate electrode and an insulator material completely isolating the gate electrode from a semiconductor material of the transistor, wherein the insulator material comprises a field oxide.    
   
   
       2 . The IGBT of  claim 1 , wherein the collector is coupled to a pad of the integrated circuit.  
   
   
       3 . The IGBT of  claim 2 , further comprising a clamp coupled between the pad and the gate of the IBBT.  
   
   
       4 . The IGBT of  claim 3 , further comprising a clamp circuit between the emitter and the gate.  
   
   
       5 . The IGBT of  claim 2 , further comprising a clamp circuit between the emitter and the gate.  
   
   
       6 . The IGBT of  claim 2 , further comprising a second said IGBT, wherein the emitter of the second said IGBT is coupled to the emitter of the IGBT of claim  22 .