Research On Preparation And Properties Of SiN_x/SiN_xO_y Films By Direct Current Pulse Magnetron Sputtering

Flexible OLED was considered to be one of the most promising display technologies of next generation. But because of the erosion of harmful gases such as H2O and O2, its lifetime can not obtain the minimal lifetime standard of commercial display—1×104h. It is an effective method to prepare protective layer on flexible substrate to prolong its lifetime. High density SiNx and SiNxOy film have excellent barrier property to gases.In this article, SiNx and SiNxOy film were prepared using Direct Current pulse Magnetron Sputtering method. The influence of deposited parameters (working pressure,gas flow ratio and film thickness) on performance and structure of SiNx and SiNxOy films is studied. The research results show that:1. under the circumstance of stationary N2/Ar gas flow ratio, as the reaction pressure increase, the content of Si-N bond in SiNx film decrease and the content of Si-O bond increase gradually. When the reaction pressure is higher than 1.0 Pa, Si-O bond become the main structure in film.2. under the condition of reaction pressure was fixed, as the N2/Ar gas flow ratio increases, the content of Si-N bond in SiNx film decreases and the content of Si-O bond increases gradually, Si-O bond become the main structure in film when the N2/Ar gas flow ratio higher than 0.6.3. Since the gas-blocking property,hydrophobicity of SiO2 are not as good as SiNx, under the condition of low pressure and low N2/Ar gas flow ratio, the content of Si-N is much higher in the film, so these properties were good; As the reaction pressure and N2/Ar gas flow ratio increase, the gas-blocking property,hydrophobicity of SiNx film become poor. SiNx film deposited at optimizing parameters has good hydrophobicity,remanent stress and gas-blocking properties,its visible light transmission rate is higher than 90%. It shows that SiNx film deposited at optimizing parameters can satisfy the requirement of flexible OLED.4. SiNxOy film was prepared using Direct Current pulse Magnetron Sputtering method at the optimizing parameters of SiNx film and O2 was added in the sputtering gases. The analysis results show that: because O is more active than N element, when the gas flow ratio (N2:Ar:O2) is 10:20:2, large quantity of Si-O bond exist in SiNxOy film and Si-O bond become the main structure when O2 ratio increase. The visible light transmission rate of SiNxOy film is higher than 90%. Since the gas-blocking property,hydrophobicity of SiO2 are not as good as SiNx, as the content of Si-O bond increases, these properties of the film become poor.