氮化硅薄膜材料的表面结构和热稳定性研究

THE SURFACE STRUCTURE AND THERMAL STABILITY OF SILICON NITRIDE FILM

研究了三种方法制备的氮化硅薄膜的组成、表面结构、热氧化稳定性以及抗离子束损伤等性能。研究发现APCVD法制备氮化硅薄膜的Si3N4含量最高，PRSD法制备的薄膜次之，而PECVD法制备的薄膜Si3N4含量最低。在PRSD薄膜中没有N－H键存在，仅有少量的Si－H键存在，薄膜的热氧化稳定性和抗离子束损伤性能最好。APCVD薄膜中含有少量的N－H和Si－H键，虽然膜层的热稳定性很好，但由于膜层具有较多的缺陷，因此其抗氧化性较差，抗离子束损伤性能也不好。对于PECVD薄膜，由于其形成温度较低，膜层中含有大量的N－H和Si－H键，因此膜层的热稳定性和抗离子束损伤性能最差。此外，还发现XPS获得的N／Si原子比和膜层的真实成分校一致，而RBS和AES由于离子束损伤效应，其结果偏低。氮化硅薄膜热稳定性差和离子束损伤的本质均因氯化硅的脱氮分解。热氧化的本质是膜层中自由硅和气氛中残余氧的氧化反应。

The silicon nitride layers were deposited on Si substrate by PECVD, APCVD and PRSD technologies. The composition, structure, thermal stability and anti-ion beam damage were studied by XPS,AES and RBS. The content of silicon nitride in deposition layer ranked, from high to low, APCVD,PRSD and PECVD layers. The sequence of the,mal stability and anti-ion damage ability was PRSD, APCVD and PECVD layers. Rapid thermal anneal treatment in N, gas can induce the decomposition of PECVD layer and the oxidation of APCVD layer. The PRSD layer was very stable for RTA treating. The nature of ion beam damage was the decomposition of silicon nitride phase. The XPS ana1ysis can give more agreeable result with the real composition of the deposition layer in the three analysis techniques