@article {1900, title = {Thermal Annealing Characteristics of Si and Mg-implanted GaN Thin Films}, journal = {Applied Physics Letters}, volume = {68}, number = {19}, year = {1995}, month = {03/1996}, pages = {2702-2704}, chapter = {2702}, abstract = {

In this letter, we report the results of ion implantation of GaN using 28Si and 23Mg species. Structural and electrical characterizations of the GaN thin films after thermal annealing show that native defects in the GaN films dominate over implant doping effects. The formation energies of the annealing induced defects are estimated to range from 1.4 to 3.6 eV. A 30 keV10^14 cm-2 Mg implant results in the decrease of the free-carrier concentration by three orders of magnitude compared to unimplanted GaN up to an annealing temperature of 690 {\textdegree}C. Furthermore, we have observed the correlation between these annealing-induced defects to both improved optical and electrical properties.

}, keywords = {annealing, crystal doping, defect states, electrical properties, gallium nitrides, ion implantation, magnesium additions, microstructure, silicon additions}, issn = {0003-6951}, doi = {10.1063/1.116314}, author = {James S. Chan and Nathan W. Cheung and Lawrence F. Schloss and Erin C. Jones and William S. Wong and Nathan Newman and Xiaohong Liu and Eicke R. Weber and A. Gassman and Michael D. Rubin} } @article {12159, title = {P-Type Gallium Nitride by Reactive Ion-Beam Molecular Beam Epitaxy with Ion Implantation, Diffusion or Coevaporation of Mg}, journal = {Applied Physics Letters}, volume = {64}, number = {1}, year = {1993}, pages = {64-66}, chapter = {64}, abstract = {

Gallium nitride is one of the most promising materials for ultraviolet and blue light-emitting diodes and lasers. The principal technical problem that limits device applications has been achieving controllable p-type doping. Molecular beam epitaxy assisted by a nitrogen ion beam produced p-type GaN when doped via ion implantation, diffusion, or coevaporation of Mg. Nearly intrinsic p-type material was also produced without intentional doping, exhibiting hole carrier concentrations of 5{\texttimes}1011 cm-3 and hole mobilities of over 400 cm2/V/s at 250 K. This value for the hole mobility is an order of magnitude greater than previously reported.

}, keywords = {carrier density, carrier mobility, crystal doping, diffusion, evaporation, gallium nitrides, ion implantation, magnesium additions, molecular beam epitaxy, p-type conductors}, issn = {0003-6951}, doi = {10.1063/1.110870}, author = {Michael D. Rubin and Nathan Newman and James S. Chan and T.C. Fu and Jennifer T. Ross} }