Activation efficiencies for a standard qualification implant in gaas annealed by a rapid thermal process

Recently a 150 keV, 2 × 10¹² cm⁻², Si²⁹ implant, with furnace annealing at 850° C for 10 min with a GaAs proximity wafer, has been proposed as a standard qualification test for semi-insulating GaAs. In general, the electrical activation efficiency of implanted wafers is determined either from Hall effect data or from capacitance-voltage (C-V) data; however, the Hall effect method requires sizable depletion corrections at low implant doses. In this paper, we examine the proposed standard, and the methods of determining activation, from three points of view: (1) rapid-thermal annealing (RTA) vs furnace annealing; (2) a Si proximity cap vs a GaAs proximity cap; and (3) Hall effect vs C-V. Our conclusions are: (1) RTA produces higher activation efficiencies, at least for our particular wafers, than furnace annealing; (2) Si and GaAs proximity caps produce nearly equivalent activation efficiencies; and (3) the Hall effect, when corrected for depletion, is a useful technique for measuring activation efficiency, and appears to be more accurate than the C-V technique.