JFET/SOS devices: processing and gamma radiation effects

A process for fabricating n-channel JFET/SOS (junction field-effect transistors on silicon-on-sapphire) has been researched. The gate p/sup +/-n junction was obtained by diffusion, and the conductive channel formed by a double ion implantation. Both enhancement and depletion mode transistors were fabricated in different processing conditions. From the results of the Co/sub 60/ /spl gamma/-ray irradiation experiments, we found that the devices had a good total dose radiation hardness. When the total dose was 5 Mrad(Si), their threshold voltages shift was less than 0.1 V. The variation of transconductance and the channel leakage current were also small.