Electrostatic Discharge Protection Device
AssigneeMacronix International Co., Ltd.
InventorsHsin-Liang Chen, Tzu-Yi Hung, Min-Hsin Wu
Life of this patent
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Abstract
An electrostatic discharge protection device includes: a semiconductor substrate; an N-type doped well on the substrate, the N-type doped well including a first N+ region and a first P+ region; a P-type doped well on the substrate, the P-type doped well including a second N+ region, a third N+ region, and a second P+ region between the second N+ region and the third N+ region; and a first contact positioned above a surface of the N-type doped well between the first N+ region and the first P+ region.
Claims20
An electrostatic discharge protection device comprising:
- a semiconductor substrate;
- a first N-type doped well and a second N-type doped well on the substrate, each of the first N-type doped well and the second N-type doped well comprising a first N+ region and a first P+ region;
- a P-type doped well between the first N-type doped well and the second N-typed doped well on the substrate, the P-type doped well comprising a second N+ region, a third N+ region, and a second P+ region between the second N+ region and the third N+ region;
- and
- a first contact and a second contact positioned above a surface of the first N-type doped well and above a surface of the second N-type doped well, respectively, between the first N+ region and the first P+ region;
- a poly resistor connected between the first N-type doped well and the second N− typed doped well.
An electrostatic discharge protection circuit comprising:
- a first bipolar junction transistor, wherein an emitter of the first bipolar junction transistor is electrically coupled to a base of the first bipolar junction transistor by a first resistance, and the first bipolar junction transistor is operable to turn on when a first voltage is applied to the emitter of the first bipolar junction transistor;
- a second bipolar junction transistor, wherein a collector of the second bipolar junction transistor is coupled to the base of the first bipolar junction transistor by a second resistance, and the second bipolar junction transistor is operable to turn on when a second voltage is applied to the emitter of the first bipolar junction transistor, the second voltage being greater than the first voltage;
- and
- a third bipolar junction transistor, wherein a collector and a base of the third bipolar junction transistor are tied to the collector and a base, respectively, of the second bipolar junction transistor, the base of the third bipolar junction transistor is electrically coupled to an emitter of the third bipolar junction transistor by a third resistance, and the third bipolar junction transistor is operable to turn on when a third voltage is applied to the emitter of the first bipolar junction transistor, the third voltage being greater than the second voltage.
A method of fabricating an electrostatic discharge protection device, the method comprising:
- providing a substrate;
- forming a first N-type well on the substrate;
- forming a second N-type well and a first P-type well within the first N-type well;
- forming a first N+ region and a first P+ region within the second N-type well, wherein the first N+ region and the first P+ region are spaced apart within the second N-type well;
- forming a second N+ region, a second P+ region, and a third N+ region within the first P-type well, wherein the second P+ region separates the second N+ region from the third N+ region;
- forming a first oxide layer, wherein the first oxide layer is between the first P+ region and the second N+ region;
- forming a second oxide layer, wherein the second oxide layer is positioned between the first N+ region and the first P+ region;
- and
- forming a contact layer on the first oxide layer and on the second oxide layer.
Dependencies are inferred from the claim text.