Polarity dependent implanted p-type dopant activation in GaN

Abstract

Here we present a direct comparison between the activation of implanted Mg ions in N-polar and Ga-polar substrates to produce p-type GaN via symmetric multicycle rapid thermal annealing (SMRTA). Physical dopant activation was achieved by annealing in moderate nitrogen pressures (3.3 MPa) in conjunction with a bi-layer cap. Photoluminescence shows activation was more readily achieved for N-polar films with measured UV luminescence up to ∼15× as intense as yellow/green luminescence compared to ∼2.4× for Ga-polar films. The greater activation of N-polar material was primarily due to a higher thermal stability compared to Ga-polar films. This demonstration of implanted Mg activation by SMRTA enables a facile route toward next generation vertical devices.