摘要 |
An ESD protection element is formed by a PN junction diode including an N+ type buried layer having a proper impurity concentration and a first P+ type buried layer and a parasitic PNP bipolar transistor which uses a second P+ type buried layer connected to a P+ type diffusion layer as the emitter, an N- type epitaxial layer as the base, and the first P+ type buried layer as the collector. The first P+ type buried layer is connected to an anode electrode, and the P+ type diffusion layer and an N+ type diffusion layer surrounding the P+ type diffusion layer are connected to a cathode electrode. When a large positive static electricity is applied to the cathode electrode, and the parasitic PNP bipolar transistor turns on to flow a large discharge current. |