Porous GaN (PGaN) produced by Pt-assisted electroless etching has been studied by Raman spectroscopy. Three different unintentionally doped GaN films grown by hydride vapor phase epitaxy on sapphire were used for this study. Pt-assisted electroless etching takes place without external contact to a current source, simplifying the generation of porous semiconductors. Raman spectra were excited with both subband gap (441.6 nm) and above-band gap (325 nm) radiation, and collected in an unpolarized backscattering configuration. In both cases, a strong increase in scattering is observed for the Raman modes, depending on the depth of the porous layer. With visible excitation, symmetry-forbidden A(1)(TO) and E-1(TO) are observed in PGaN, and spectral line shape analysis reveals the presence of the forbidden E-1(LO) mode as well. Raman spectra were also analyzed using an effective medium theory, revealing extraordinary LO phonon scattering with visible, and Frohlich scattering with UV, excitation. In addition a quasi-LO phonon is observed in the visible spectrum. All of the characteristic features of PGaN Raman scattering: symmetry-forbidden modes, quasi-LO scattering, and strong Fr6hlich mode scattering, can be attributed to the dendritic porous morphology of PGaN. (C) 2004 American Vacuum Society.