Dependence of impurity incorporation on the polar direction of GaN film growth

We have investigated the dependence of impurity incorporation on the polar direction of GaN growth by using secondary ion mass spectroscopy (SIMS). GaN films were deposited under conditions used for growing device-quality materials on sapphire substrates while controlling their polar direction. It was found that the polarity of the GaN film influences the incorporation of impurities. SIMS analysis has revealed that the impurities related to carbon, oxygen, and aluminum are more readily incorporated into N-face GaN films. (C) 2000 American Institute of Physics. [S0003-6951(00)04715-X].