Negative charge thin film, AlO(subscript x)N(subscript y) has been fabricated to passivate the surface of crystalline silicon solar cell and reduce the surface recombination velocity. The fabrication of the film was using ion-beam sputtering deposition and following annealing in oxygen ambient. The fixed charge density has increased from 10^11 cm^(-2) to 2.26×10^12 cm^(-2) after annealing. The solar cell efficiency increased from 15.9% to 17.3%.