| 摘要 |
PURPOSE:To completely eliminate a defect due to a parasitic thyristor effect by completely insulating a protective diode region made of a lateral Zener diode from a vertical field effect transistor forming region. CONSTITUTION:An n<+> type silicon substrate 1 form forming a drain region of an N-channel DMOSFET, an n type epitaxial layer 2, a gate p type region 3, an n<+> type source region 4, a gate insulating film 5, a polycrystalline silicn electrode 6, source and drain electrodes 7, 8 and a field insulating film 9 are provided. p type regions 11, 12, 13 for forming lateral p-n-p type Zener diode region and an n type region 14, source and gate electrodes 17, 18 are provided in the p type well 10. The Zener diode region is completely encircled by an insulating film 15 and a semiconductor insulating layer 16, electrically completely insulated and isolated from the drain region of the vertical FET, and a parasitic thyristor is not inserted between the gate and the drain of the vertical FET. |
