In order to study preparation process recipes and nonlinear optical properties of Si/SiN

x

superla-ttice

Si/SiN

x

superlattice has been fabricated by RF magnetron sputtering technique and thermal annealing.The superlattice has been characterized by absorption measurement

and X-ray diffraction.Nonlinear optical properties of Si/SiN

x

superlattice was probed by a Z-scan technique at λ=1064 nm.The experimental results show that the nonlinear refractive index of the sample is a negative value and the nonlinear absorption is two-photon absorption.The real and imaginary parts of χ

(3)

have been found to be 1.27×10

-7

(esu)and 1.51×10

-8

(esu)according to the experimental data of Z-scan curve.The value of Si/SiN

x

superlattice is larger 5 scales than that of bulk silicon.The nonlinear mechanism of the material was discussed.The enhancement of non-linear refractive index is mainly attributed to intensive quantum confinement.The results indicate that such Si/SiN

x

superlattice material could be applied to the optoelectronics and microelectronics industry since it is compatible with Si technology.