Patent ID: 8421117

Claim:
A semiconductor device, comprising: a first epitaxial layer of a first general conductivity type formed on a semiconductor layer of the first general conductivity type; a second epitaxial layer of a second general conductivity type formed on the first epitaxial layer; an isolation layer of the first general conductivity type formed in the second epitaxial layer and dividing the second epitaxial layer into a first protection diode forming region and a second protection diode forming region; a first embedded layer of the second general conductivity type extending from the first epitaxial layer toward the second epitaxial layer in the first protection diode forming region; a second embedded layer of the second general conductivity type extending from a bottom of the first embedded layer so as to connect to the second epitaxial layer in the first protection diode forming region; a PN junction formed with the first embedded layer and the first epitaxial layer in the first protection diode forming region; an upward diffusion layer of the first general conductivity type extending from the semiconductor layer so as to connect to the second epitaxial layer in the second protection diode forming region; and a Zener diode formed with the PN junction, using the first embedded layer as a cathode layer and the first epitaxial layer as an anode layer.