ELECTRICAL ISOLATION OF PIN PHOTODIODE DEVICES BY OXYGEN-ION BOMBARDMENT

Using the Hall-effect measurements, the resistance changes in Si-doped (5 x 10(17) cm(-3)), 1 mu m thick epilayers of InGaAs and in InP/InGa As pin structures were studied as functions of multiple-energy oxygen ion dose, implant temperature (-196 and 18 degrees C), and rapid therm al-anneal (RTA) temperatures. In the case of InGaAs epilayers, the pea k resistivity is attained following post-implant RTA at 400-500 degree s C, with samples implanted at -196 degrees C exhibiting at least a fa ctor of 10 larger resistivity than those implanted at 18 degrees C (10 (6) vs. 10(5) Ohm/square). The thermal stability of the induced resist ivity is also dependent on the implant temperature and the ion dose. T he results suggest that for InGaAs layers, sheet resistances in excess of 10(6) Ohm/square, stable to temperatures in excess of the anticipa ted pin device processing temperatures, can be produced by O-16 ion im plantation. The use of O ion bombardment to produce planar, implant-is olated pin photodiodes with excellent dark-current and frequency respo nse characteristics has been demonstrated.