摘要
采用离子束溅射技术在Si片上先后连续淀积Ti膜和Co膜,对Co/Ti/Si三元体系固相反应特性进行了研究。在氮气氛下对Co/Ti/Si样品进行热处理,结果表明,样品薄层电阻及薄膜结构随热处理温度的升高发生显著变化。原来处于样品表面的Co穿过Ti膜与Si发生反应在薄膜内部形成钴硅化合物,在薄膜表面Ti与气氛中的N结合形成TiN。实验在有SiO_2图形的Si片上溅射Co/Ti,通过两步退火和选择腐蚀可在硅区域表面获得线条整齐的自对准TiN/CoSi_2复合薄膜。
Ti and Co films were sequentially deposited on Si substrates by ion beam sputtering. Theternary Solid phase reaction of Co/Ti/Si was investigated.The thermal annealing of Co/Ti/Sisamples was performed in a nitrogen ambient.The results show that the sheet resistance andstructure of samples change dramatically with increasing of annealing temperature. OriginalCo at the surface diffuses through Ti and react with the underlying Si to form Cosilicide, andTi moves to the surface to form a TiN layer on top of CoSi_2. Depositing a bilayer of Co/Ti onpatterned Si wafers, a good self-aligned TiN/CoSi_2 composite contact was formed on Si regionsby a two step annealing with a two step selective etching.
