以不同温度真空原位退火工艺为手段,促使制备在单晶Si(100)和Al2O3基底上的Cu-W薄膜发生相变。用X射线衍射(XRD)分析晶体取向,偏振相位移技术分析薄膜残余应力。结果表明,随退火温度变化,薄膜相变呈现连续变化,由初始的非晶态晶化,出现类W的亚稳态固溶体相,以及随退火温度的进一步增加,发生Spinodal分解,亚稳固溶体完全分解为W和Cu两相。薄膜发生相变时产生拉应力作用,而在晶粒生长阶段,拉应力释放。
The phase transition of Copper-tungsten films deposited on Si (100) and Al2O3 substrates took place by means of in situ annealing in vacuum chamber at different temperatures. X-ray diffraction (XRD) and the polarization phase shift technique were employed to characterize the microstructure and residual stress of Cu-W films, respectively. The results indicated that the two successive but distinctive stages of phase transition appeared with the change of annealing temperatures, i.e., W (Cu) solution formation and two-phase crystalline (W and Cu) structure formation. The relationship between phase transition and residual stress was investigated, the tensile stress was caused during phase transition, whereas it was released with crystalline growth.