氩离子束辅助淀积Cu/Si薄膜相变研究

PHASE TRANSITION OF Cu/Si SYSTEM OBTAINED BY ION BEAM ASSISTED DEPOSITION

用实验的方法研究了PVD，IBAD和IBAD－PVD复合等不同方法在硅基底上镀制Cu膜的结构特点及真空退火时的结构变化。利用XRD，RBS，SEM等分析手段对比研究它们的结构变化特点，发现IBADCu（20nm）层＋PVDCu膜（350nm）的复合薄膜样品在退火前无新相生成，而退火后形成ε相，且不同于通常Cu－Si退火系统中首先生成γ相和η”相，然后再由γ和η”反应生成ε相的相序。分析认为在Cu－Si界面退火反应系统中，ε相的形核是得到稳定相结构的关键。

Cu films were formed on Si (100) substrates by three different methods: physical vapor de position (PVD ), ion beam assisted deposition (IBAD ) and a combined IBAD - PVD technique. ε - phase (Cu15Si4) was formed directly at the interface of 1he 15keV Ar+ IBAD Cu film (350 nm) and the Si sub strates during the deposition processes. In the combined film [IBAD Cu (20 nm) +PVD Cu (350 nm)]no new phase was observed until the sample had undergone an annealing treatment (300℃, 30min), in which the ε-phase was formed. The phase sequence of the Cu-Si system in the combined films is quite different from those observed in a typical annealing process. Nucleation of ε-phase is the key factor to obtain a ther modynarmically stable phase at the Cu-Si interface during the annealing process.