Electro-static discharge protection devices having a low trigger voltage

Abstract

An electro-static discharge (ESD) protection device includes a first well region and a second well region disposed to contact each other, a first diffusion region and a second diffusion region disposed in the first well region spaced apart from each other, a third diffusion region and a fourth diffusion region disposed in the second well region spaced apart from each other, a resistive pattern coupled to the first diffusion region through a first contact plug, a first electrode coupled to the second diffusion region through a second contact plug and electrically coupled to the resistive pattern, and a second electrode coupled to the third diffusion region through a third contact plug and coupled to the fourth diffusion region through a fourth contact plug.

What is claimed is: 
     
         1 . An electro-static discharge (ESD) protection device comprising:
 a first well region of a first conductivity type;   a second well region of a second conductivity type disposed to contact with the first well region;   a first diffusion region of the first conductivity type disposed in the first well region;   a second diffusion region of the second conductivity type disposed in the first well region spaced apart from the first diffusion region;   a third diffusion region of the second conductivity type disposed in the second well region;   a fourth diffusion region of the first conductivity type disposed in the second well region spaced apart from the third diffusion region;   a resistive pattern coupled to the first diffusion region through a first contact plug;   a first electrode coupled to the second diffusion region through a second contact plug and electrically coupled to the resistive pattern; and   a second electrode coupled to the third diffusion region through a third contact plug and coupled to the fourth diffusion region through a fourth contact plug.   
     
     
         2 . The ESD protection device of  claim 1 , wherein the first conductivity type is a P-type and the second conductivity type is an N-type. 
     
     
         3 . The ESD protection device of  claim 1 ,
 wherein the first and fourth diffusion regions have an impurity concentration which is higher than an impurity concentration of the first well region; and   wherein the second and third diffusion regions have an impurity concentration which is higher than an impurity concentration of the second well region.   
     
     
         4 . The ESD protection device of  claim 1 , wherein the resistive pattern includes a polysilicon material. 
     
     
         5 . The ESD protection device of  claim 4 , wherein each of the first and second electrodes includes a metal material. 
     
     
         6 . The ESD protection device of  claim 5 ,
 wherein the first electrode is coupled to a supply terminal of a ground voltage; and   wherein the second electrode is coupled to a pad of a circuit to be protected.   
     
     
         7 . The ESD protection device of  claim 1 , further comprising a fifth diffusion region of the second conductivity type disposed in the first well region spaced apart from the first and second diffusion regions. 
     
     
         8 . The ESD protection device of  claim 7 , wherein the first electrode is coupled to the fifth diffusion region through a fifth contact plug. 
     
     
         9 . The ESD protection device of  claim 7 , wherein the fifth diffusion region has an impurity concentration which is higher than an impurity concentration of the second well region. 
     
     
         10 . The ESD protection device of  claim 7 , further comprising a sixth diffusion region of the first conductivity type disposed in the first well region spaced apart from the first diffusion region, the second diffusion region, and the fifth diffusion region. 
     
     
         11 . The ESD protection device of  claim 10 , wherein the sixth diffusion region has an impurity concentration which is higher than an impurity concentration of the first well region. 
     
     
         12 . The ESD protection device of  claim 11 , wherein the sixth diffusion region is electrically floated. 
     
     
         13 . An electro-static discharge (ESD) protection device comprising:
 a first well region of a first conductivity type;   a second well region of a second conductivity type disposed to contact the first well region;   a first diffusion region of the first conductivity type disposed in the first well region;   a plurality of second diffusion regions of the second conductivity type disposed in the first well region to be separated from each other by the first diffusion region in a first direction;   a third diffusion region of the second conductivity type disposed in the second well region;   a plurality of fourth diffusion regions of the first conductivity type disposed in the second well region to be separated from each other by the third diffusion region in the first direction;   a resistive pattern coupled to the first diffusion region through a first contact plug;   a first electrode coupled to the plurality of second diffusion regions through respective ones of second contact plugs and electrically coupled to the resistive pattern; and   a second electrode coupled to the third diffusion region through a third contact plug and coupled to the plurality of fourth diffusion regions through respective ones of fourth contact plugs.   
     
     
         14 . The ESD protection device of  claim 13 , wherein the first conductivity type is a P-type and the second conductivity type is an N-type. 
     
     
         15 . The ESD protection device of  claim 13 ,
 wherein the first and fourth diffusion regions have an impurity concentration which is higher than an impurity concentration of the first well region; and   wherein the second and third diffusion regions have an impurity concentration which is higher than an impurity concentration of the second well region.   
     
     
         16 . The ESD protection device of  claim 13 , wherein the resistive pattern includes a polysilicon material. 
     
     
         17 . The ESD protection device of  claim 16 , wherein each of the first and second electrodes includes a metal material. 
     
     
         18 . The ESD protection device of  claim 17 ,
 wherein the first electrode is coupled to a supply terminal of a ground voltage; and   wherein the second electrode is coupled to a pad of a circuit to be protected.   
     
     
         19 . An electro-static discharge (ESD) protection device comprising:
 a silicon controlled rectifier (SCR) component coupled between an anode and a cathode to provide a discharge current path,   wherein the SCR component includes:
 a first bipolar junction transistor (BJT) of a PNP structure having an emitter coupled to the anode, a base coupled to a first node, and a collector coupled to a second node; 
 a second BJT of an NPN structure having an emitter coupled to the cathode, a base coupled to the second node, and a collector coupled to the first node; and 
 an external resistive component coupled between the second node and the emitter of the second BJT. 
   
     
     
         20 . The ESD protection device of  claim 19 ,
 wherein the anode is coupled to a pad of a circuit to be protected; and   wherein the cathode is coupled to a supply terminal of a ground voltage.   
     
     
         21 . The ESD protection device of  claim 19 , further comprising:
 a first parasitic resistive component existing between the anode and the first node; and   a second parasitic resistive component existing between the second node and the external resistive component.   
     
     
         22 . The ESD protection device of  claim 19 , further comprising:
 a third MT of an NPN structure having an emitter coupled to the cathode, a base coupled to the second node, and a collector coupled to the first node.