Metal modulation epitaxy growth for extremely high hole concentrations above 1019 cm-3 in GaN

The free hole carriers in GaN have been limited to concentrations in the low 10(18) cm(-3) range due to the deep activation energy, lower solubility, and compensation from defects, therefore, limiting doping efficiency to about 1%. Herein, we report an enhanced doping efficiency up to similar to 10% in GaN by a periodic doping, metal modulation epitaxy growth technique. The hole concentrations grown by periodically modulating Ga atoms and Mg dopants were over similar to 1.5 x 10(19) cm(-3). (C) 2008 American Institute of Physics. [DOI: 10.1063/1.3005640]