The Effect Of Preparation Process On The Structure And Optical Waveguide Characteristics Of Zinc Nitride Thin Films

With the rapid development of science and technology,semiconductor thin film materials with its excellent semiconductor properties and special small size effect has become a hot topic of material research.Zn₃N₂ thin film material of zinc is both belong to the class and nitrogen ?-?compounds,caused the wide attention of scientific researchers.Zn₃N₂ thin film has the advantages of high carrier migration rate,high conductivity and forbidden band width for the different preparation methods,meanwhile Zn₃N₂ thin film is easy to prepare and easy to operate.In this study,Zn₃N₂ thin films were prepared on Al₂O₃,MgO and Si<111> substrates by RF reactive magnetron sputtering technique,the purity of 99.99% pure metal zinc target was placed in nitrogen and argon atmosphere.The effects of substrate type,substrate temperature and the flow ratio of nitrogen and argon on the crystallinity,surface morphology and optical waveguide properties of Zn₃N₂ thin films were investigated.Zn₃N₂ thin films were grown on Al₂O₃,MgO and Si <111> under the same experimental conditions.X-ray diffraction and atomic force microscopy showed that the size of Zn₃N₂ thin on the sapphire substrate was larger and the structure of the thin film was more compact.The grain size of the thin film deposited on the Si <111> substrate was smaller,the roughness larger.And the diffraction peak of Zn₃N₂ thin film is not found on the MgO substrate.The effects of different substrate temperature on the lattice structure and optical waveguide properties of zinc nitride thin films were investigated by sputtering Zn₃N₂ films at room temperature,200? and 400?.It was found that the growth of Zn₃N₂ thin films was higher at200?,and the crystallinity of Zn₃N₂ films was lower at room temperature and higher temperature than that at 200 ?.When the substrate temperature When the temperature is high,the surface roughness of Zn₃N₂ film increases.Using the prism coupling technique to study the optical waveguide properties of the grown Zn₃N₂ thin films,two TE modes and one TM mode were observed on the sapphire substrate,and the same number of modes were observed on the MgO substrate.And the effective refractive index of the grown Zn₃N₂ thin film was measured.On the Al₂O₃ substrate,n0 = 2.338,ne= 1.757,no = 2.213,ne = 1.737 on the MgO substrate.