Silicon nitride films prepared by high-density plasma chemical vapor deposition for solar cell applications

Silicon nitride films were deposited by means of high-density inductively coupled plasma chemical vapor deposition in a planar coil reactor. The process gases used were pure nitrogen and a mixture of silane and helium. Buried contact solar cells, passivated by the silicon nitride layer, show efficiency above 17%. Strong H-atom release from the growing SiN film and Si-N bond healing are responsible for the improved electrical and passivation properties of the SiN film. This paper presents the optimal refractive index of SiN for a single layer antireflection (SLAR) coating in solar cell applications.