US 7,601,991 B2
On-chip structure for electrostatic discharge (ESD) protection
Javier A. Salcedo, Orlando, Fla. (US); Juin J. Liou, Oviedo, Fla. (US); Joseph C. Bernier, Palm Bay, Fla. (US); and Donald K. Whitney, Jr., W. Melbourne, Fla. (US)
Assigned to Intersil Americas Inc., Milpitas, Calif. (US); and University of Central Florida, Orlando, Fla. (US)
Filed on Mar. 26, 2007, as Appl. No. 11/691,018.
Application 11/691018 is a division of application No. 11/032154, filed on Jan. 11, 2005, granted, now 7,202,114.
Claims priority of provisional application 60/535816, filed on Jan. 13, 2004.
Prior Publication US 2008/0012044 A1, Jan. 17, 2008
Int. Cl. H01L 29/72 (2006.01)
U.S. Cl. 257—173  [257/174; 257/E29.181] 14 Claims
OG exemplary drawing
 
1. A high holding, low voltage trigger silicon controlled rectifier device having first and second terminals, the device comprising:
an N-type layer on a P-type substrate;
an N-type tub region having a first portion extending from a top surface of the N-type layer to a first location of the P-type substrate, a second portion extending into the P-type substrate, and a third portion extending from the top surface of the N-type layer to a second location of the P-type substrate different from the first location;
adjacent P-type and N-type well regions in the top surface of the N-type layer between walls of the first portion and over the second portion the N-type tub region;
spaced source and drain regions of a first conductivity type in one of the wells of a conductivity type opposite the first conductivity type, the drain region extending into the other of the wells of the same conductivity type;
an insulated gate over the space between the source and drain regions;
a region of the opposite conductivity type in the other well;
a contact region of the first conductivity type in the other well and a contact region of the other conductivity type in the one well; and
a first contact connecting the gate and the source region and forming the first terminal and a second contact connected to the region of the opposite conductivity type and forming the second terminal,
wherein the P-type well region and the N-type well region both contact the N-type layer along their entire bottom surfaces.