Circuit including a resistive element, a diode, and a switch and a method of using the same

摘要

An ESD protection element can have a high ESD protection characteristic which has a desired breakdown voltage and flows a large discharge current. A junction diode is formed by an N+ type buried layer having a proper impurity concentration and a P+ type buried layer. The P+ type buried layer is combined with a P+ type drawing layer to penetrate an N− type epitaxial layer and be connected to an anode element. An N+ type diffusion layer and a P+ typed diffusion layer connected to an surrounding the N+ type diffusion layer are formed in the N− epitaxial layer surrounded by the P+ type buried layer etc. The N+ type diffusion layer and P+ type diffusion layer are connected to a cathode electrode. An ESD protection element is formed by the PN junction diode and a parasitic PNP bipolar transistor which uses the P+ type diffusion layer as an emitted, the N− type epitaxial layer as the base, and the P+ type drawing layer etc. as the collector.

主权项

1. An integrated circuit comprising:
a substrate; a resistor having a first terminal, a second terminal, and a resistive body between the first and second terminals, wherein:
the first terminal includes an N+ type diffusion layer adjacent to a first surface of an N− type epitaxial layer and is coupled to a first power supply terminal; andthe second terminal includes an N+ type buried layer that is adjacent to a second surface of the N− type epitaxial layer opposite the first surface of the N− type epitaxial layer; a diode having an anode and a cathode, wherein the cathode includes the N+ type buried layer, and the anode includes a P+ type buried layer that abuts the N+ type buried layer; a switch having a first current terminal, a second current terminal, and a control electrode, wherein the first current terminal includes a P+ type diffusion layer, the control electrode is coupled to the second terminal of the resistor and the cathode of the diode, wherein the second current terminal includes a P+ drawing layer that abuts the P+ type buried layer and is electrically connected to a second power supply terminal; and a cathode electrode, wherein:
a portion of the N− type epitaxial layer that includes the resistive body of the resistor and the control electrode of the switch is spaced apart from the substrate by the N+ type buried layer;from a plan view at the first surface, the N+ type diffusion layer is completely surrounded by the P+ type diffusion layer, the P+ type diffusion layer is completely surrounded by the N− type epitaxial layer, and the portion of the N− type epitaxial layer is completely surrounded by the P+ type drawing layer; andthe cathode electrode directly contacts the P+ type diffusion layer and the N+ type diffusion layer.