利用声表面波（SAW）的频散特性来表征超大规模集成电路（ULSI）互连系统中低介电常数（k）薄膜的物性具有准确、快速、对材料无损伤等突出优点。研究了Si（100）衬底上淀积低k薄膜的分层结构中，SAW沿任意方向传播的色散关系，引入坐标变换后，单层薄膜特征矩阵从9阶降到6阶，双层薄膜特征矩阵从15阶降到10阶，大幅度提高了计算速度，有利于生产ULSI过程中的在线监测。

The surface acoustic waves (SAWs) technique is becoming an attractive tool for accurately and nondestructively characterizing the mechanical property of the brittle low dielectric constant (low-k) thin film. The theoretical equations for describing SAWs propagating on the multi-layered structure are derived in this study. The dispersion features of SAWs propagating on different structures of low-k/SiO2/Si substrate, SiO2/low-k/Si substrate, low-k/Si substrate, and low-k/Cu/Si substrate are investigated to instruct an accurate and facile fitting process for determining Young’s modulus of low-k films. The dependence of dispersion relation on the film thickness, elastic modulus of low-k materials as well as frequency are provided and discussed in detail. The study shows an obvious influence of layered structure on the dispersion relation of SAWs. For a fixed structure, the dispersion curvature increases with the decrease of Young’s modulus of low-k films.