| US 7,538,395 B2 | ||
| Method of forming low capacitance ESD device and structure therefor | ||
| Thomas Keena, Chandler, Ariz. (US); Ki Chang, Kansas City, Mo. (US); Francine Y. Robb, Fountain Hills, Ariz. (US); Mingjiao Liu, Gilbert, Ariz. (US); Ali Salih, Mesa, Ariz. (US); John Michael Parsey, Jr., Phoenix, Ariz. (US); and George Chang, Tempe, Ariz. (US) | ||
| Assigned to Semiconductor Components Industries, L.L.C., Phoenix, Ariz. (US) | ||
| Filed on Sep. 21, 2007, as Appl. No. 11/859,570. | ||
| Prior Publication US 2009/0079022 A1, Mar. 26, 2009 | ||
| Int. Cl. H01L 23/62 (2006.01); G11C 11/36 (2006.01); H01L 21/00 (2006.01) | ||
| U.S. Cl. 257—361 [257/94; 257/96; 257/101; 257/106; 257/199; 257/461; 257/509; 257/929; 257/E29.005; 257/E29.335; 365/175; 438/22; 438/47; 438/309; 438/966; 438/983] | 7 Claims |
| 1. An electro static discharge (ESD) device comprising:
a first terminal of the ESD device;
a second terminal of the ESD device;
a zener diode having an anode coupled to the second terminal of the ESD device and also having a cathode;
a first P-N diode coupled in series with the zener diode, the first P-N diode having an anode and a cathode; and
a second P-N diode coupled in parallel with series combination of the zener diode and the first P-N diode, the second P-N
diode having a cathode and also having an anode that is coupled to the anode of the zener diode and 15 to the second terminal
of the ESD device;
wherein the ESD device comprises:
a semiconductor substrate of a first conductivity type having a first peak doping concentration no less than approximately
IX1019 atoms/cm3;
a first semiconductor region of a second conductivity type having approximately the first peak doping concentration and forming
a first P-N junction with the semiconductor substrate wherein the first P-N junction forms a junction of the zener diode;
a second semiconductor region of the second conductivity type on the first semiconductor region and also on a portion of the
semiconductor substrate wherein the second semiconductor region has a second peak doping concentration that is less than the
first peak doping concentration;
a first doped region of the first conductivity type positioned in the second semiconductor region and overlying the first
semiconductor region, the first doped region spaced a distance of at least two microns from the first semiconductor region,
the first doped region having approximately the first peak doping concentration; and
a first trench isolation region extending from a top surface of the second semiconductor region, through the first semiconductor
region, and into the semiconductor substrate wherein the first trench isolation region surrounds an outside perimeter of the
first doped region.
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