Electrostatic discharge protection circuit

Abstract

An electrostatic discharge protection circuit has a substrate; a first P-well installed on the substrate and having a first P+-doped region and a first N+-doped region, both of which are connected to ground; a second P-well installed on the substrate and having a second P+-doped region and a second N+-doped region, both of which are connected to a power supply voltage; and a third P-well installed on the substrate and having a third N+-doped region, a third P+-doped region, and a fourth N+-doped region, all of which are for input/output signals.

1 . An electrostatic discharge protection circuit comprising: 
 a substrate;    a first P-well installed on the substrate, the first P-well comprising a first P+ region and a first N+ region, both of the first P+ and the first N+ regions connected to ground;    a second P-well installed on the substrate, the second P-well comprising a second P+ region and a second N+ region, both of the second P+ and the second N+ regions connected to a voltage source; and    a third P-well installed on the substrate, the third P-well comprising a third N+ region, a third P+ region and a fourth N+ region, all of the third N+ region, the third P+ region and the fourth N+ region for inputting/outputting signals.    
   
   
       2 . The electrostatic discharge protection circuit of  claim 1 , wherein the substrate is an N-substrate.  
   
   
       3 . The electrostatic discharge protection circuit of  claim 2 , wherein the N-substrate comprises a V T  implant installed between the first P-well and the second P-well and between the second P-well and the third P-well.  
   
   
       4 . The electrostatic discharge protection circuit of  claim 1 , wherein the substrate is a P-substrate, the electrostatic discharge protection circuit further comprising a deep N-well installed on the P-substrate, the first, the second and the third P-well all installed on the deep N-well.  
   
   
       5 . The electrostatic discharge protection circuit of claim  1 further comprising a shallow trench isolation (STI) structure installed on the substrate for restricting the movement of ions in the substrate.  
   
   
       6 . The electrostatic discharge protection circuit of  claim 1  further comprising polysilicon disposed on all the regions.  
   
   
       7 . The electrostatic discharge protection circuit of  claim 6 , wherein the polysilicon is of predetermined shape, the adjustable-shaped polysilicon having capabilities of changing a ballasting resistance, of blocking and dispersing electrostatic currents, and of increasing an area from which the regions generate ions and reducing a driving voltage.  
   
   
       8 . The electrostatic discharge protection circuit of  claim 7 , wherein the polysilicon is disposed in the shape of a rectangle, a cross, or a Tee.  
   
   
       9 . The electrostatic discharge protection circuit of  claim 7 , wherein the polysilicon is symmetrically disposed.  
   
   
       10 . The electrostatic discharge protection circuit of  claim 1  having an octagonal layout.  
   
   
       11 . The electrostatic discharge protection circuit of  claim 10 , wherein the octagonal layout comprises a central region, and the third P-well is installed in the central region.  
   
   
       12 . The electrostatic discharge protection circuit of  claim 11 , wherein the first P-well is installed above the third P-well.  
   
   
       13 . The electrostatic discharge protection circuit of  claim 12 , wherein the second P-well is installed below the third P-well.  
   
   
       14 . The electrostatic discharge protection circuit of  claim 11 , wherein the first P-well is installed below the third P-well.  
   
   
       15 . The electrostatic discharge protection circuit of  claim 14 , wherein the second P-well is installed above the third P-well.  
   
   
       16 . The electrostatic discharge protection circuit of  claim 10 , wherein any one in a first group consisting of the first N+ region, the second N+ region, the third N+ region, and the fourth N+ region has an area smaller than that of any one in a second group consisting of the first P+ region, the second P+ region, and the third P+ region.  
   
   
       17 . An electrostatic discharge protection circuit for a radio-frequency circuit, the electrostatic discharge protection circuit comprising: 
 at least an electrostatic discharge protection unit comprising: 
 a guiding structure; and  
 an equivalent capacitor.  
   
   
   
       18 . The electrostatic discharge protection circuit of  claim 17  comprising a plurality of serially connected electrostatic discharge protection units.  
   
   
       19 . The electrostatic discharge protection circuit of  claim 17 , wherein the guiding structure is a coplanar wave-guide, a transmission line, or an equivalent inductor.  
   
   
       20 . The electrostatic discharge protection circuit of  claim 17 , wherein the electrostatic discharge protection units have a quantity relating to a bandwidth of the radio-frequency circuit.  
   
   
       21 . The electrostatic discharge protection circuit of  claim 17  further comprising a matching impedance of 50 ohms.  
   
   
       22 . An electrostatic discharge protection circuit for a broadband circuit, the electrostatic discharge protection circuit comprising: 
 a first electrostatic discharge protection unit for electrically connecting to pins of an integrated circuit chip of the broadband circuit; and    a second electrostatic discharge protection unit connected in series with the first electrostatic discharge protection unit for electrically connecting to an inner circuit of the broadband circuit.    
   
   
       23 . The electrostatic discharge protection circuit of  claim 22 , wherein either of the first electrostatic discharge protection unit and the second electrostatic discharge protection unit comprises a guiding structure and an equivalent capacitor.  
   
   
       24 . The electrostatic discharge protection circuit of  claim 23 , wherein the guiding structure is a coplanar wave-guide, a transmission line, or an equivalent inductor.  
   
   
       25 . The electrostatic discharge protection circuit of  claim 22  further comprising a third electrostatic discharge protection unit installed between the first electrostatic discharge protection unit and the second electrostatic discharge protection unit.  
   
   
       26 . The electrostatic discharge protection circuit of  claim 25 , wherein either of the first electrostatic discharge protection unit and the second electrostatic discharge protection unit has an area larger than that of the third electrostatic discharge protection unit.  
   
   
       27 . The electrostatic discharge protection circuit of  claim 25 , wherein the third electrostatic discharge protection unit comprises a guiding structure and an equivalent capacitor.  
   
   
       28 . The electrostatic discharge protection circuit of  claim 27 , wherein the guiding structure is a coplanar wave-guide, a transmission line, or an equivalent inductor.  
   
   
       29 . The electrostatic discharge protection circuit of  claim 22  further comprising third and fourth electrostatic discharge protection units, both of which are installed between the first electrostatic discharge protection unit and the second electrostatic discharge protection unit.  
   
   
       30 . The electrostatic discharge protection circuit of  claim 29 , wherein the first, the second, the third and the fourth electrostatic discharge protection units are disposed to have a layout in the shape of an open rectangle.  
   
   
       31 . The electrostatic discharge protection circuit of  claim 29 , wherein either of the first electrostatic discharge protection unit and the second electrostatic discharge protection unit has an area larger than that of either of the third electrostatic discharge protection unit and the fourth electrostatic discharge protection unit.  
   
   
       32 . The electrostatic discharge protection circuit of  claim 29 , wherein either of the third electrostatic discharge protection unit and the fourth electrostatic discharge protection unit comprises a guiding structure and an equivalent capacitor.  
   
   
       33 . The electrostatic discharge protection circuit of  claim 32 , wherein the guiding structure is a coplanar wave-guide, a transmission line, or an equivalent inductor.  
   
   
       34 . The electrostatic discharge protection circuit of  claim 29  further comprising a fifth electrostatic discharge protection unit installed between the third electrostatic discharge protection unit and the fourth electrostatic discharge protection unit.  
   
   
       35 . The electrostatic discharge protection circuit of  claim 34 , wherein either of the first electrostatic discharge protection unit and the second electrostatic discharge protection unit has an area larger than that of either the third electrostatic discharge protection unit and the fourth electrostatic discharge protection unit, and either of the third electrostatic discharge protection unit and the fourth electrostatic discharge protection unit has an area larger than that of the fifth electrostatic discharge protection unit.  
   
   
       36 . The electrostatic discharge protection circuit of  claim 34 , wherein the fifth electrostatic discharge protection unit comprises a guiding structure and an equivalent capacitor.  
   
   
       37 . The electrostatic discharge protection circuit of  claim 36 , wherein the guiding structure is a coplanar wave-guide, a transmission line, or an equivalent inductor.  
   
   
       38 . The electrostatic discharge protection circuit of  claim 22  further comprising a matching impedance of  50  ohms.  
   
   
       39 . An electrostatic discharge protection circuit for an ultra broadband circuit, the electrostatic discharge protection circuit comprising: 
 a first electrostatic discharge protection unit for electrically connecting to pins of an integrated circuit chip of the ultra broadband circuit;    a second electrostatic discharge protection unit for electrically connecting to an inner circuit of the ultra broadband circuit;    a plurality of third electrostatic discharge protection units electrically connected to the first electrostatic discharge protection unit and to the second electrostatic discharge protection unit; and    a plurality of fourth electrostatic discharge protection units electrically connected to the third electrostatic discharge protection units.    
   
   
       40 . The electrostatic discharge protection circuit of  claim 39 , wherein the first electrostatic discharge protection unit is connected in series with one of the third electrostatic discharge protection units, one of the fourth electrostatic discharge protection units, another of the third electrostatic discharge protection units, and the second electrostatic discharge protection unit sequentially.  
   
   
       41 . The electrostatic discharge protection circuit of  claim 39 , wherein either of the first electrostatic discharge protection unit and the second electrostatic discharge protection unit has an area larger than that of any one of the third electrostatic discharge protection units.  
   
   
       42 . The electrostatic discharge protection circuit of  claim 39 , wherein any one of the third electrostatic discharge protection units has an area larger than that of any one of the fourth electrostatic discharge protection units.  
   
   
       43 . The electrostatic discharge protection circuit of  claim 39 , wherein any one in a group consisting of the first, the second, the third and the fourth electrostatic discharge protection units comprises a guiding structure and an equivalent capacitor.  
   
   
       44 . The electrostatic discharge protection circuit of  claim 43 , wherein the guiding structure is a coplanar wave-guide, a transmission line or an equivalent inductor.  
   
   
       45 . The electrostatic discharge protection circuit of  claim 39  further comprising a matching impedance of 50 ohms.  
   
   
       46 . An electrostatic discharge protection circuit for an ultra broadband circuit, the electrostatic discharge protection circuit comprising: 
 a first electrostatic discharge protection unit for electrically connecting to pins of an integrated circuit chip of the ultra broadband circuit;    a plurality of second electrostatic discharge protection units for electrically connecting to an inner circuit of the ultra broadband circuit;    a plurality of third electrostatic discharge protection units electrically connected to the first electrostatic discharge protection unit and to the second electrostatic discharge protection units; and    a fourth electrostatic discharge protection unit electrically connected to the third electrostatic discharge protection units.    
   
   
       47 . The electrostatic discharge protection circuit of  claim 46 , wherein the first electrostatic discharge protection unit is electrically connected in series with one of the third electrostatic discharge protection units, the fourth electrostatic discharge protection unit, another of the third electrostatic discharge protection units, and one of the second electrostatic discharge protection units sequentially.  
   
   
       48 . The electrostatic discharge protection circuit of  claim 46 , wherein either of the first electrostatic discharge protection unit and the second electrostatic discharge protection unit has an area larger than that of any one of the third electrostatic discharge protection units.  
   
   
       49 . The electrostatic discharge protection circuit of  claim 46 , wherein any one the third electrostatic discharge protection units has an area larger than that of the fourth electrostatic discharge protection unit.  
   
   
       50 . The electrostatic discharge protection circuit of  claim 46 , wherein any one in a group consisting of the first, the second, the third and the fourth electrostatic discharge protection units comprises a guiding structure and an equivalent capacitor.  
   
   
       51 . The electrostatic discharge protection circuit of  claim 50 , wherein the guiding structure is a coplanar wave-guide, a transmission line, or an equivalent inductor.  
   
   
       52 . The electrostatic discharge protection circuit of  claim 46  further comprising a matching impedance of 50 ohms.