A new, planar, fully ion-implanted indium phosphide (InP) junction field-effect transistor (JFET) fabrication process is described which utilizes n* source-drain implantation, Be and Be/P p+ gate implantation, a AuZn/Ni/TiW/Au gate metallization and proximity rapid thermal annealing. The JFETs exhibit a gate leakage current of approximately 40 nA at -8 V for a 1 pm x 150 μm gate, a reverse breakdown voltage of 17.5 V at 25 μA, and a maximum transconductance of 140 mS/mm. The addition of a Ni layer in the gate metallization significantly improves its adhesion. The specific contact resistance of the new gate structure is measured to be as low as 2 x 105 ohm-cm2,which is the lowest value reported to date for contacts to p-type InP.
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