A technique to enhance the hole concentration in activated Mg-doped p-type GaN epitaxial layers is described. The method consists of depositing a porous plasma-enhanced chemical vapor deposited SiOx layer on top of p-GaN after which the sample is heated to 950 degrees C in nitrogen ambient for 1 min followed by the removal of the SiOx layer in a buffered HF solution. A significant improvement of the conductivity of the p-GaN layer has been obtained. (c) 2005 The Electrochemical Society.