Floating guard region and process of manufacture for semiconductor reverse conducting switching device using spaced MOS transistors having a common drain region

A metal oxide semiconductor type device for switching high voltage and high current circuits;

• said device comprising a body of semiconductor material of one conductivity type extending to a given depth and having a planar surface;
• first, second and third spaced regions of the other conductivity type formed in said body and terminating on said planar surface and having depths less than said given depth;
• said second region disposed between said first and third regions;
• fourth and fifth regions of said one conductivity type formed within said first and third regions respectively and extending to said planar surface;
• said first and fourth regions and said third and fifth regions defining respective first and second elongated laterial conduction channels;
• first and second gate electrodes insulated from and disposed above said first and second conduction channels and operable to invert said conduction channels to control their conductivity;
• said second region defining a floating guard region.