| 摘要 |
PROBLEM TO BE SOLVED: To provide a configuration capable of effectively suppressing an operation of a parasitic bipolar transistor in a semiconductor device having a Zener diode on a semiconductor substrate.SOLUTION: An N-type conductivity type first semiconductor layer (an SOI layer 2) is provided in an SOI substrate 5. On one surface of the SOI substrate 5, a P-type conductivity type second semiconductor layer (a P well layer 22 and an anode P+ layer 26) is formed. An N-type conductivity type third semiconductor layer (an N+ layer 24) is formed adjacently to the second semiconductor layer. A Zener diode ZD is configured by the second semiconductor layer and the third semiconductor layer (the N+ layer 24). Further, an N-type conductivity type fourth semiconductor layer 30 is formed outside and on one surface of the second semiconductor layer on the SOI substrate 5. A potential of an electrode layer connected to the fourth semiconductor layer 30 is higher than that of a cathode electrode connected to the third semiconductor layer (the N+ layer 24). |
