Effect of growth conditions on electrical properties of Mg-doped p-GaN

In this work the effect of carrier gas and post-growth activation conditions on the electrical properties of Mg-doped p-GaN single layers grown in a vertical flow close-coupled showerhead MOCVD system is investigated. The results of Hall effect measurements show that although the optimal Mg precursor flow rate depends on the growth atmosphere and is smaller when N2 is used as a carrier gas, similar electrical properties could be realized with both H2 and N2 carrier gases. The results of SIMS analysis demonstrate that while Mg incorporation is higher for N2 carrier gas, the efficiency of Mg activation is higher when H2 is used as carrier gas. We have also observed that the structural quality of N2 grown layers is substantially lower compared to the H2 case. © 2006 Elsevier B.V. All rights reserved.