STRUCTURES AND TECHNIQUES FOR ELECTRO-STATIC DISCHARGE (ESD) PROTECTION USING RING STRUCTURED DIODES
Electro-Static Discharge (ESD) protection using at least one ring-shape diode is disclosed. The ring-shape diode can be constructed from polysilicon, active region body on insulated substrate, or junction diode on silicon substrate. The diodes can have a first type of implant in an outer ring and a second type of implant in an inner ring to serve as two terminals of a diode coupled through contacts, vias, or metals. The two types of implant ring regions are separated with an isolation structure. The isolation can be LOCOS, STI, dummy gate, or silicide block layer (SBL). The ESD structure has at least a ring-shape diode with a first terminal coupled to an I/O pad and the second terminal coupled to a first supply voltage. The contours of the ring-shape diode can be circles, polygons, or other shapes. The ring-shape ESD structures can be multiple and be constructed in concentric manner.
1 . A diode in an integrated circuit, comprising:
a ring-shape semiconductor body that having:
a first type of implant in the outer ring;
a second type of implant in the inner ring;
the two types of implant rings are separated by a spacing; and
an isolation structure provided between the first and the second type of implant regions; and
wherein the first and the second implant ring regions are coupled through contacts and vias to serve as the first and the second terminals of a diode.
2 . A diode as recited in claim 1 , wherein the semiconductor body is a polysilicon or active region body on an insulated substrate or a silicon substrate.
3 . A diode as recited in claim 1 , wherein the isolation structure is a silicide block layer, LOCOS (LOCal Oxidation), STI (Shallow Trench Isolation), or dummy gate.
4 . An ESD protection structure provided in an integrated circuit, the ESD protection structure comprising:
an I/O pad; and
at least one ring-shape diode having:
a first type of implant in the outer ring region to serve as a first terminal of a diode;
a second type of implant in the inner ring region to serve as a second terminal of a diode;
the two types of implant regions being separated by a space;
an isolation structure between the first and the second implant regions; and
one of the terminals of the diode being coupled to an I/O pad while the other terminal being coupled to a supply voltage to protect the circuits associated with the I/O pad from high voltage surges.
5 . An ESD protection structure recited in claim 4 , wherein the semiconductor body is a polysilicon or active region body on an insulated substrate or a silicon substrate.
6 . An ESD protection structure as recited in claim 4 , wherein the isolation is a silicide block layer, LOCOS (LOCal Oxidation), STI (Shallow Trench Isolation), or dummy gate.
7 . An ESD protection structure as recited in claim 4 , wherein the contour of the diode is a circle or polygon.
8 . An ESD protection structure as recited in claim 4 , wherein the diode is comparable with the I/O pad size and/or is able to be hidden under the I/O pad partially or wholly.
9 . An ESD protection structure as recited in claim 4 , wherein at least one of the diode regions are coupled to adjacent active areas that are thermally coupled to a conductive substrate.
10 . An ESD protection structure as recited in claim 4 , wherein the ESD protection structure has a second diode, wherein the first diode has a first terminal coupled to the I/O pad and a second terminal coupled to a first supply voltage, and wherein the second diode has a second terminal coupled to the I/O pad and the first terminal coupled to a second supply voltage.
11 . An electronic system, comprising:
at least one integrated circuit, the integrated circuit having at least one ESD protection structure,
the at least one ESD protection structure includes at least:
at least one ring-shape diode having a first type of implant in an outer ring region, and a second type of implant in an inner ring region, the first type of implant serving as a first terminal for the at least one ring-shape diode, the second type of implant serving as a second terminal for the at least one ring-shape diode,
wherein the first and second types of implants being separated with a space,
wherein an isolation structure is provided between the first and the second implant regions, and
wherein one of the first and second terminals of the at least one ring-shape diode is coupled to an I/O pad while the other of the first and second terminals being coupled to a supply voltage to protect circuits associated with the I/O pad from high voltage surges.
12 . An electronic system as recited in claim 11 , wherein the ring-shape diode comprises polysilicon or an active region body on an insulated substrate or a silicon substrate.
13 . An electronic system as recited in claim 11 , wherein the isolation structure is a silicide block layer, LOCOS (LOCal Oxidation), STI (Shallow Trench Isolation), or dummy gate.
14 . An electronic system as recited in claim 11 , wherein the contour of the at least one ring-shape diode is a circle or polygon.
15 . An electronic system as recited in claim 11 , wherein the at least one ring-shape diode is comparable to the I/O pad size and/or is hidden under the I/O pad partially or wholly.
16 . An electronic system as recited in claim 11 , wherein the implant ring regions of the at least one ring-shape diode are coupled to adjacent active areas that are thermally coupled to a conductive substrate.
17 . An electronic system as recited in claim 11 ,
wherein the at least one ring-shape diode is a first ring-shape diode, and
wherein the ESD protection structure has a second ring-shape diode, wherein the first ring-shape diode has a first terminal coupled to the I/O pad and the second terminal coupled to a first supply voltage, and the second ring-shape diode has a second terminal coupled to the I/O pad and the first terminal coupled to a second supply voltage.
18 . A method for providing an Electro-Static Discharge (ESD) protection, comprising:
providing at least one ring-shape diode that includes at least (i) a first type of implant region in the outer portion of the ring to serve as a first terminal of the ring-shape diode; (ii) a second type of implant region in the inner portion of the ring to serve as a second terminal of the ring-shape diode; (iii) the first and second type of implant regions being separated with a space; (iv) an isolation structure provided between the first and the second type of implant regions; and (v) one of the first and second terminals of the at least one ring-shape diode being coupled to an I/O pad and the other of the first and second terminals being coupled to a supply voltage,
wherein the ring-shape diode can protect one or more circuits from a high voltage surge.
19 . A method as recited in claim 18 , wherein the ring-shape diode is a polysilicon or an active region body on an insulated substrate or a silicon substrate.
20 . A method as recited in claim 18 , wherein the isolation structure is a silicide block layer, LOCOS (LOCal Oxidation), STI (Shallow Trench Isolation), or dummy gate.
21 . A method as recited in claim 18 , wherein the ring-shape diode has a contour, and wherein the contour of the diode is a circle or a polygon.
22 . A method as recited in claim 18 , wherein the method comprises:
providing a second ring-shape diode, wherein the first ring-shape diode has the first terminal coupled to an I/O pad and the second terminal coupled to a first supply voltage, and wherein the second ring-shape diode has a second terminal coupled to the I/O pad and the first terminal coupled to a second supply voltage.