Semiconductor device including poly-silicon junction field-effect transistor and manufacturing method thereof

A semiconductor device, comprising:

• an oxide layer disposed on a substrate;
• a single poly-silicon layer comprising first and second doped poly-silicon regions and a undoped poly-silicon region and disposed on the oxide layer;
• a highly doped first conductivity type drain and source regions disposed in the first and second doped poly-silicon regions, respectively;
• a highly doped second conductivity type gate region formed in the single poly-silicon layer disposed between the highly doped first conductivity type drain and source regions,
• wherein the highly doped first conductivity type drain and source regions, and the highly doped second conductivity type gate region are each formed above the insulating film;
• and
• a first non-sal layer disposed on the single poly-silicon layer over a portion of the highly doped first conductivity type drain region and a portion of the highly doped second conductivity type gate region.