Aim To investigate the influence of ion density( n i) on the deposition of wurtzite GaN films on the substrate of α Al 2O 3(0001) by electron cyclotron resonance plasma. Methods Langmuir probe measurement, Double crystal X ray diffraction and Hall measurement were used. Results The quality of GaN film strongly depended on its growth condition. The higher ion density resulted in a higher amount ratio of N/Ga and a lower background electron concentration of GaN film. When the GaN was prepared in the ion density of 2 0×10 11 cm -3 , the amount ratio of N/Ga was close to 1, the electron background density was 3 7×10 18 cm -3 and its full width at half magnitude(FWHM) was 16?arcmin. Conclusion The quality of GaN film can be improved by raising the plasma density.
