Process for manufacture of radiation resistant power MOSFET and radiation resistant power MOSFET

A MOS-gated semiconductor device having short-circuit current limiting ballasting;

• said MOS-gated semiconductor device comprising a die of monocrystalline silicon having flat parallel upper and lower surfaces and having a body region extending from said upper surface which is of one conductivity type;
• a plurality of laterally spaced channel regions of the opposite conductivity type extending from said upper surface of said die and into said body region;
• a respective source region for each of said channel regions;
• said source regions being of said one conductivity type and extending from said upper surface of said die into their said respective channel regions for a depth less than the depth of their said respective channel regions;
• a gate electrode means disposed atop said upper surface and insulated from said spaced channel regions and operable to invert said spaced channel regions in response to the application of a suitable gate voltage to said gate electrode means;
• a metallic electrode disposed atop said upper surface and connected to at least each of said source regions;
• each of said source regions having at least a relatively high resistance portion disposed in series with the current path extending from said metallic electrode through said channel regions and to said body region;
• said metallic electrode forming a Schottky barrier connection of increased resistance to said relatively high resistance portions of said source regions to act as respective ballasting resistors in parallel with one another and to limit short-circuit current.