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ABSTRACT The III-V nitride-containing semiconductors InN, GaN, and AlN and their ternary alloys are the focus of extensive research for application to visible light emitters and as the basis for high temperature electronics. Recent advances in ion implantation doping of GaN and studies of the effect of rapid thermal annealing up to 1100 *C are making new device structures possible. Both p- and n-type implantation doping of GaN has been achieved using Mg coimplanted with P for p-type and Si-implantation for n-type. Electrical activation was achieved by rapid thermal anneals in excess of 1000 *C. Atomic force microscopy studies of the surface of GaN after a series of anneals from 750 to 1100 °C shows that the surface morphology gets smoother following anneals in Ar or N2. The photoluminescence of the annealed samples also shows enhanced bandedge emission for both annealing ambients. For the deep level emission near 2.2 eV, the sample annealed in N2 shows slightly reduced emission while the sample annealed in Ar shows increased emission. These annealing results suggest a combination of defect interactions occur during the high temperature processing.

INTRODUCTION The III-V nitride-containing semiconductors InN, GaN, and AIN and their ternary alloys are attracting renewed interest for application to visible light emittersl, 2 and as the basis for high temperature electronics. 3 -5 Their attractive material properties include bandgaps ranging from 1.9 eV (InN) to 6.2 eV (AIN), an energy gap (Eg(GaN) = 3.39 eV) close to the high breakdown fields, high saturation drift short wavelength region of the visible spectrum, 6 velocities and relatively high carrier mobilities. 7 There have been limited reports of the implantation properties of the 111-V nitrides. 8 Early work by Pankove focused on the optical properties of GaN implanted with an array of 9 elements while Khan investigated the implantation of Be or N in GaN and ALGaNl6 to improve Schottky barrier characteristics. Recently there have been reports on the implant isolation properties of Ill-Nitride materials 11, 12, 1. but there has been only one report of the achievement of implantation doping of GaN. 14 In this work we report in more detail on the properties of implantation doping in GaN. Specifically, Hall data for the sheet carrier concentration versus annealing temperature is reported. Variable temperature Hall data is reported and used to estimate the ionization energy levels for implanted Mg and Si in GaN.

801 Mat. Res. Soc. Symp. Proc. Vol. 395 ©1996Materials Research Society

In addition, secondary ion mass spectroscopy (SIMS) data is presented for as-implanted and annealed samples to study the redistribution properties of implanted Mg and Si in GaN. Furthermore, since an implant activation anneal in excess of 1000 'C is required to achieve electrical activation, data for the effect of such an anneal on the morphology and luminescence properties of GaN is presented. Results are also given for ohmic contact formation to Si-implanted GaN. EXPERIMENTAL The Ga