The influence of substrate polarity on the properties of InN layers grown by high-pressure chemical vapor deposition has been studied. The 2 Theta-omega x-ray diffraction scans on InN layers deposited on polar GaN epilayers revealed single-phase InN(0002) with a full width at half maximum (FWHM) of around 200 arc sec. InN layers grown on N-polar GaN exhibit larger FWHMs. Rocking curve analysis confirmed single-phase InN for both growth polarities, with FWHM values for omega-RC(002) at 2080 arc sec for InN grown on Ga-polar templates. The A(1)(LO) Raman mode analysis shows higher free carrier concentrations in InN grown on N-polar templates, indicating that polarity affects the incorporation of impurities. (c) 2008 American Institute of Physics.